package org.succlz123.utils;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
/**
* <p>Operations on {@link String} that are
* {@code null} safe.</p>
*
* <ul>
* <li><b>IsEmpty/IsBlank</b>
* - checks if a String contains text</li>
* <li><b>Trim/Strip</b>
* - removes leading and trailing whitespace</li>
* <li><b>Equals</b>
* - compares two strings null-safe</li>
* <li><b>startsWith</b>
* - check if a String starts with a prefix null-safe</li>
* <li><b>endsWith</b>
* - check if a String ends with a suffix null-safe</li>
* <li><b>IndexOf/LastIndexOf/Contains</b>
* - null-safe index-of checks
* <li><b>IndexOfAny/LastIndexOfAny/IndexOfAnyBut/LastIndexOfAnyBut</b>
* - index-of any of a set of Strings</li>
* <li><b>ContainsOnly/ContainsNone/ContainsAny</b>
* - does String contains only/none/any of these characters</li>
* <li><b>Substring/Left/Right/Mid</b>
* - null-safe substring extractions</li>
* <li><b>SubstringBefore/SubstringAfter/SubstringBetween</b>
* - substring extraction relative to other strings</li>
* <li><b>Split/Join</b>
* - splits a String into an array of substrings and vice versa</li>
* <li><b>Remove/Delete</b>
* - removes part of a String</li>
* <li><b>Replace</b>
* - Searches a String and replaces one String with another</li>
* <li><b>Chomp/Chop</b>
* - removes the last part of a String</li>
* <li><b>LeftPad/RightPad/Center/Repeat</b>
* - pads a String</li>
* <li><b>UpperCase/LowerCase/SwapCase/Capitalize/Uncapitalize</b>
* - changes the case of a String</li>
* <li><b>CountMatches</b>
* - counts the number of occurrences of one String in another</li>
* <li><b>IsAlpha/IsNumeric/IsWhitespace/IsAsciiPrintable</b>
* - checks the characters in a String</li>
* <li><b>DefaultString</b>
* - protects against a null input String</li>
* <li><b>Reverse/ReverseDelimited</b>
* - reverses a String</li>
* <li><b>Abbreviate</b>
* - abbreviates a string using ellipsis</li>
* <li><b>Difference</b>
* - compares Strings and reports on their differences</li>
* <li><b>LevenshteinDistance</b>
* - the number of changes needed to change one String into another</li>
* </ul>
*
* <p>The {@code StringUtils} class defines certain words related to
* String handling.</p>
*
* <ul>
* <li>null - {@code null}</li>
* <li>empty - a zero-length string ({@code ""})</li>
* <li>space - the space character ({@code ' '}, char 32)</li>
* <li>whitespace - the characters defined by {@link Character#isWhitespace(char)}</li>
* <li>trim - the characters <= 32 as in {@link String#trim()}</li>
* </ul>
*
* <p>{@code StringUtils} handles {@code null} input Strings quietly.
* That is to say that a {@code null} input will return {@code null}.
* Where a {@code boolean} or {@code int} is being returned
* details vary by method.</p>
*
* <p>A side effect of the {@code null} handling is that a
* {@code NullPointerException} should be considered a bug in
* {@code StringUtils}.</p>
*
* <p>Methods in this class give sample code to explain their operation.
* The symbol {@code *} is used to indicate any input including {@code null}.</p>
*
* <p>#ThreadSafe#</p>
* @see String
* @since 1.0
* @version $Id: StringUtils.java 1199894 2011-11-09 17:53:59Z ggregory $
*/
public class StringUtils {
/**
* The empty String {@code ""}.
*/
public static final String EMPTY = "";
/**
* Represents a failed index search.
*/
public static final int INDEX_NOT_FOUND = -1;
/**
* <p>The maximum size to which the padding constant(s) can expand.</p>
*/
private static final int PAD_LIMIT = 8192;
/**
* <p>{@code StringUtils} instances should NOT be constructed in
* standard programming. Instead, the class should be used as
* {@code StringUtils.trim(" foo ");}.</p>
*
* <p>This constructor is public to permit tools that require a JavaBean
* instance to operate.</p>
*/
public StringUtils() {
super();
}
// Empty checks
//-----------------------------------------------------------------------
/**
* <p>Checks if a CharSequence is empty ("") or null.</p>
*
* <pre>
* StringUtils.isEmpty(null) = true
* StringUtils.isEmpty("") = true
* StringUtils.isEmpty(" ") = false
* StringUtils.isEmpty("bob") = false
* StringUtils.isEmpty(" bob ") = false
* </pre>
*
* <p>NOTE: This method changed in Lang version 2.0.
* It no longer trims the CharSequence.
* That functionality is available in isBlank().</p>
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if the CharSequence is empty or null
*/
public static boolean isEmpty(CharSequence cs) {
return cs == null || cs.length() == 0;
}
/**
* <p>Checks if a CharSequence is whitespace, empty ("") or null.</p>
*
* <pre>
* StringUtils.isBlank(null) = true
* StringUtils.isBlank("") = true
* StringUtils.isBlank(" ") = true
* StringUtils.isBlank("bob") = false
* StringUtils.isBlank(" bob ") = false
* </pre>
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if the CharSequence is null, empty or whitespace
*/
public static boolean isBlank(CharSequence cs) {
int strLen;
if (cs == null || (strLen = cs.length()) == 0) {
return true;
}
for (int i = 0; i < strLen; i++) {
if (Character.isWhitespace(cs.charAt(i)) == false) {
return false;
}
}
return true;
}
// Trim
//-----------------------------------------------------------------------
/**
* <p>Removes control characters (char <= 32) from both
* ends of this String, handling {@code null} by returning
* {@code null}.</p>
*
* <p>The String is trimmed using {@link String#trim()}.
* Trim removes start and end characters <= 32.
* To strip whitespace use {@link #strip(String)}.</p>
*
* <p>To trim your choice of characters, use the
* {@link #strip(String, String)} methods.</p>
*
* <pre>
* StringUtils.trim(null) = null
* StringUtils.trim("") = ""
* StringUtils.trim(" ") = ""
* StringUtils.trim("abc") = "abc"
* StringUtils.trim(" abc ") = "abc"
* </pre>
*
* @param str the String to be trimmed, may be null
* @return the trimmed string, {@code null} if null String input
*/
public static String trim(String str) {
return str == null ? null : str.trim();
}
/**
* <p>Removes control characters (char <= 32) from both
* ends of this String returning {@code null} if the String is
* empty ("") after the trim or if it is {@code null}.
*
* <p>The String is trimmed using {@link String#trim()}.
* Trim removes start and end characters <= 32.
* To strip whitespace use {@link #stripToNull(String)}.</p>
*
* <pre>
* StringUtils.trimToNull(null) = null
* StringUtils.trimToNull("") = null
* StringUtils.trimToNull(" ") = null
* StringUtils.trimToNull("abc") = "abc"
* StringUtils.trimToNull(" abc ") = "abc"
* </pre>
*
* @param str the String to be trimmed, may be null
* @return the trimmed String,
* {@code null} if only chars <= 32, empty or null String input
*/
public static String trimToNull(String str) {
String ts = trim(str);
return isEmpty(ts) ? null : ts;
}
/**
* <p>Removes control characters (char <= 32) from both
* ends of this String returning an empty String ("") if the String
* is empty ("") after the trim or if it is {@code null}.
*
* <p>The String is trimmed using {@link String#trim()}.
* Trim removes start and end characters <= 32.
* To strip whitespace use {@link #stripToEmpty(String)}.</p>
*
* <pre>
* StringUtils.trimToEmpty(null) = ""
* StringUtils.trimToEmpty("") = ""
* StringUtils.trimToEmpty(" ") = ""
* StringUtils.trimToEmpty("abc") = "abc"
* StringUtils.trimToEmpty(" abc ") = "abc"
* </pre>
*
* @param str the String to be trimmed, may be null
* @return the trimmed String, or an empty String if {@code null} input
*/
public static String trimToEmpty(String str) {
return str == null ? EMPTY : str.trim();
}
// Stripping
//-----------------------------------------------------------------------
/**
* <p>Strips whitespace from the start and end of a String.</p>
*
* <p>This is similar to {@link #trim(String)} but removes whitespace.
* Whitespace is defined by {@link Character#isWhitespace(char)}.</p>
*
* <p>A {@code null} input String returns {@code null}.</p>
*
* <pre>
* StringUtils.strip(null) = null
* StringUtils.strip("") = ""
* StringUtils.strip(" ") = ""
* StringUtils.strip("abc") = "abc"
* StringUtils.strip(" abc") = "abc"
* StringUtils.strip("abc ") = "abc"
* StringUtils.strip(" abc ") = "abc"
* StringUtils.strip(" ab c ") = "ab c"
* </pre>
*
* @param str the String to remove whitespace from, may be null
* @return the stripped String, {@code null} if null String input
*/
public static String strip(String str) {
return strip(str, null);
}
/**
* <p>Strips whitespace from the start and end of a String returning
* {@code null} if the String is empty ("") after the strip.</p>
*
* <p>This is similar to {@link #trimToNull(String)} but removes whitespace.
* Whitespace is defined by {@link Character#isWhitespace(char)}.</p>
*
* <pre>
* StringUtils.stripToNull(null) = null
* StringUtils.stripToNull("") = null
* StringUtils.stripToNull(" ") = null
* StringUtils.stripToNull("abc") = "abc"
* StringUtils.stripToNull(" abc") = "abc"
* StringUtils.stripToNull("abc ") = "abc"
* StringUtils.stripToNull(" abc ") = "abc"
* StringUtils.stripToNull(" ab c ") = "ab c"
* </pre>
*
* @param str the String to be stripped, may be null
* @return the stripped String,
* {@code null} if whitespace, empty or null String input
*/
public static String stripToNull(String str) {
if (str == null) {
return null;
}
str = strip(str, null);
return str.length() == 0 ? null : str;
}
/**
* <p>Strips whitespace from the start and end of a String returning
* an empty String if {@code null} input.</p>
*
* <p>This is similar to {@link #trimToEmpty(String)} but removes whitespace.
* Whitespace is defined by {@link Character#isWhitespace(char)}.</p>
*
* <pre>
* StringUtils.stripToEmpty(null) = ""
* StringUtils.stripToEmpty("") = ""
* StringUtils.stripToEmpty(" ") = ""
* StringUtils.stripToEmpty("abc") = "abc"
* StringUtils.stripToEmpty(" abc") = "abc"
* StringUtils.stripToEmpty("abc ") = "abc"
* StringUtils.stripToEmpty(" abc ") = "abc"
* StringUtils.stripToEmpty(" ab c ") = "ab c"
* </pre>
*
* @param str the String to be stripped, may be null
* @return the trimmed String, or an empty String if {@code null} input
*/
public static String stripToEmpty(String str) {
return str == null ? EMPTY : strip(str, null);
}
/**
* <p>Strips any of a set of characters from the start and end of a String.
* This is similar to {@link String#trim()} but allows the characters
* to be stripped to be controlled.</p>
*
* <p>A {@code null} input String returns {@code null}.
* An empty string ("") input returns the empty string.</p>
*
* <p>If the stripChars String is {@code null}, whitespace is
* stripped as defined by {@link Character#isWhitespace(char)}.
* Alternatively use {@link #strip(String)}.</p>
*
* <pre>
* StringUtils.strip(null, *) = null
* StringUtils.strip("", *) = ""
* StringUtils.strip("abc", null) = "abc"
* StringUtils.strip(" abc", null) = "abc"
* StringUtils.strip("abc ", null) = "abc"
* StringUtils.strip(" abc ", null) = "abc"
* StringUtils.strip(" abcyx", "xyz") = " abc"
* </pre>
*
* @param str the String to remove characters from, may be null
* @param stripChars the characters to remove, null treated as whitespace
* @return the stripped String, {@code null} if null String input
*/
public static String strip(String str, String stripChars) {
if (isEmpty(str)) {
return str;
}
str = stripStart(str, stripChars);
return stripEnd(str, stripChars);
}
/**
* <p>Strips any of a set of characters from the start of a String.</p>
*
* <p>A {@code null} input String returns {@code null}.
* An empty string ("") input returns the empty string.</p>
*
* <p>If the stripChars String is {@code null}, whitespace is
* stripped as defined by {@link Character#isWhitespace(char)}.</p>
*
* <pre>
* StringUtils.stripStart(null, *) = null
* StringUtils.stripStart("", *) = ""
* StringUtils.stripStart("abc", "") = "abc"
* StringUtils.stripStart("abc", null) = "abc"
* StringUtils.stripStart(" abc", null) = "abc"
* StringUtils.stripStart("abc ", null) = "abc "
* StringUtils.stripStart(" abc ", null) = "abc "
* StringUtils.stripStart("yxabc ", "xyz") = "abc "
* </pre>
*
* @param str the String to remove characters from, may be null
* @param stripChars the characters to remove, null treated as whitespace
* @return the stripped String, {@code null} if null String input
*/
public static String stripStart(String str, String stripChars) {
int strLen;
if (str == null || (strLen = str.length()) == 0) {
return str;
}
int start = 0;
if (stripChars == null) {
while (start != strLen && Character.isWhitespace(str.charAt(start))) {
start++;
}
} else if (stripChars.length() == 0) {
return str;
} else {
while (start != strLen && stripChars.indexOf(str.charAt(start)) != INDEX_NOT_FOUND) {
start++;
}
}
return str.substring(start);
}
/**
* <p>Strips any of a set of characters from the end of a String.</p>
*
* <p>A {@code null} input String returns {@code null}.
* An empty string ("") input returns the empty string.</p>
*
* <p>If the stripChars String is {@code null}, whitespace is
* stripped as defined by {@link Character#isWhitespace(char)}.</p>
*
* <pre>
* StringUtils.stripEnd(null, *) = null
* StringUtils.stripEnd("", *) = ""
* StringUtils.stripEnd("abc", "") = "abc"
* StringUtils.stripEnd("abc", null) = "abc"
* StringUtils.stripEnd(" abc", null) = " abc"
* StringUtils.stripEnd("abc ", null) = "abc"
* StringUtils.stripEnd(" abc ", null) = " abc"
* StringUtils.stripEnd(" abcyx", "xyz") = " abc"
* StringUtils.stripEnd("120.00", ".0") = "12"
* </pre>
*
* @param str the String to remove characters from, may be null
* @param stripChars the set of characters to remove, null treated as whitespace
* @return the stripped String, {@code null} if null String input
*/
public static String stripEnd(String str, String stripChars) {
int end;
if (str == null || (end = str.length()) == 0) {
return str;
}
if (stripChars == null) {
while (end != 0 && Character.isWhitespace(str.charAt(end - 1))) {
end--;
}
} else if (stripChars.length() == 0) {
return str;
} else {
while (end != 0 && stripChars.indexOf(str.charAt(end - 1)) != INDEX_NOT_FOUND) {
end--;
}
}
return str.substring(0, end);
}
// StripAll
//-----------------------------------------------------------------------
/**
* <p>Strips whitespace from the start and end of every String in an array.
* Whitespace is defined by {@link Character#isWhitespace(char)}.</p>
*
* <p>A new array is returned each time, except for length zero.
* A {@code null} array will return {@code null}.
* An empty array will return itself.
* A {@code null} array entry will be ignored.</p>
*
* <pre>
* StringUtils.stripAll(null) = null
* StringUtils.stripAll([]) = []
* StringUtils.stripAll(["abc", " abc"]) = ["abc", "abc"]
* StringUtils.stripAll(["abc ", null]) = ["abc", null]
* </pre>
*
* @param strs the array to remove whitespace from, may be null
* @return the stripped Strings, {@code null} if null array input
*/
public static String[] stripAll(String... strs) {
return stripAll(strs, null);
}
/**
* <p>Strips any of a set of characters from the start and end of every
* String in an array.</p>
* Whitespace is defined by {@link Character#isWhitespace(char)}.</p>
*
* <p>A new array is returned each time, except for length zero.
* A {@code null} array will return {@code null}.
* An empty array will return itself.
* A {@code null} array entry will be ignored.
* A {@code null} stripChars will strip whitespace as defined by
* {@link Character#isWhitespace(char)}.</p>
*
* <pre>
* StringUtils.stripAll(null, *) = null
* StringUtils.stripAll([], *) = []
* StringUtils.stripAll(["abc", " abc"], null) = ["abc", "abc"]
* StringUtils.stripAll(["abc ", null], null) = ["abc", null]
* StringUtils.stripAll(["abc ", null], "yz") = ["abc ", null]
* StringUtils.stripAll(["yabcz", null], "yz") = ["abc", null]
* </pre>
*
* @param strs the array to remove characters from, may be null
* @param stripChars the characters to remove, null treated as whitespace
* @return the stripped Strings, {@code null} if null array input
*/
public static String[] stripAll(String[] strs, String stripChars) {
int strsLen;
if (strs == null || (strsLen = strs.length) == 0) {
return strs;
}
String[] newArr = new String[strsLen];
for (int i = 0; i < strsLen; i++) {
newArr[i] = strip(strs[i], stripChars);
}
return newArr;
}
// Equals
//-----------------------------------------------------------------------
/**
* <p>Compares two CharSequences, returning {@code true} if they are equal.</p>
*
* <p>{@code null}s are handled without exceptions. Two {@code null}
* references are considered to be equal. The comparison is case sensitive.</p>
*
* <pre>
* StringUtils.equals(null, null) = true
* StringUtils.equals(null, "abc") = false
* StringUtils.equals("abc", null) = false
* StringUtils.equals("abc", "abc") = true
* StringUtils.equals("abc", "ABC") = false
* </pre>
*
* @see String#equals(Object)
* @param cs1 the first CharSequence, may be null
* @param cs2 the second CharSequence, may be null
* @return {@code true} if the CharSequences are equal, case sensitive, or
* both {@code null}
*/
public static boolean equals(CharSequence cs1, CharSequence cs2) {
return cs1 == null ? cs2 == null : cs1.equals(cs2);
}
/**
* <p>Compares two CharSequences, returning {@code true} if they are equal ignoring
* the case.</p>
*
* <p>{@code null}s are handled without exceptions. Two {@code null}
* references are considered equal. Comparison is case insensitive.</p>
*
* <pre>
* StringUtils.equalsIgnoreCase(null, null) = true
* StringUtils.equalsIgnoreCase(null, "abc") = false
* StringUtils.equalsIgnoreCase("abc", null) = false
* StringUtils.equalsIgnoreCase("abc", "abc") = true
* StringUtils.equalsIgnoreCase("abc", "ABC") = true
* </pre>
*
* @param str1 the first CharSequence, may be null
* @param str2 the second CharSequence, may be null
* @return {@code true} if the CharSequence are equal, case insensitive, or
* both {@code null}
*/
public static boolean equalsIgnoreCase(CharSequence str1, CharSequence str2) {
if (str1 == null || str2 == null) {
return str1 == str2;
} else if (str1.length() != str2.length()) {
return false;
}
return CharSequenceUtils.regionMatches(str1, true, 0, str2, 0, Math.max(str1.length(), str2.length()));
}
// IndexOf
//-----------------------------------------------------------------------
/**
* <p>Finds the first index within a CharSequence, handling {@code null}.
* This method uses {@link String#indexOf(int, int)} if possible.</p>
*
* <p>A {@code null} or empty ("") CharSequence will return {@code INDEX_NOT_FOUND (-1)}.</p>
*
* <pre>
* StringUtils.indexOf(null, *) = -1
* StringUtils.indexOf("", *) = -1
* StringUtils.indexOf("aabaabaa", 'a') = 0
* StringUtils.indexOf("aabaabaa", 'b') = 2
* </pre>
*
* @param seq the CharSequence to check, may be null
* @param searchChar the character to find
* @return the first index of the search character,
* -1 if no match or {@code null} string input
*/
public static int indexOf(CharSequence seq, int searchChar) {
if (isEmpty(seq)) {
return INDEX_NOT_FOUND;
}
return CharSequenceUtils.indexOf(seq, searchChar, 0);
}
/**
* <p>Finds the first index within a CharSequence from a start position,
* handling {@code null}.
* This method uses {@link String#indexOf(int, int)} if possible.</p>
*
* <p>A {@code null} or empty ("") CharSequence will return {@code (INDEX_NOT_FOUND) -1}.
* A negative start position is treated as zero.
* A start position greater than the string length returns {@code -1}.</p>
*
* <pre>
* StringUtils.indexOf(null, *, *) = -1
* StringUtils.indexOf("", *, *) = -1
* StringUtils.indexOf("aabaabaa", 'b', 0) = 2
* StringUtils.indexOf("aabaabaa", 'b', 3) = 5
* StringUtils.indexOf("aabaabaa", 'b', 9) = -1
* StringUtils.indexOf("aabaabaa", 'b', -1) = 2
* </pre>
*
* @param seq the CharSequence to check, may be null
* @param searchChar the character to find
* @param startPos the start position, negative treated as zero
* @return the first index of the search character,
* -1 if no match or {@code null} string input
*/
public static int indexOf(CharSequence seq, int searchChar, int startPos) {
if (isEmpty(seq)) {
return INDEX_NOT_FOUND;
}
return CharSequenceUtils.indexOf(seq, searchChar, startPos);
}
/**
* <p>Finds the first index within a CharSequence, handling {@code null}.
* This method uses {@link String#indexOf(String, int)} if possible.</p>
*
* <p>A {@code null} CharSequence will return {@code -1}.</p>
*
* <pre>
* StringUtils.indexOf(null, *) = -1
* StringUtils.indexOf(*, null) = -1
* StringUtils.indexOf("", "") = 0
* StringUtils.indexOf("", *) = -1 (except when * = "")
* StringUtils.indexOf("aabaabaa", "a") = 0
* StringUtils.indexOf("aabaabaa", "b") = 2
* StringUtils.indexOf("aabaabaa", "ab") = 1
* StringUtils.indexOf("aabaabaa", "") = 0
* </pre>
*
* @param seq the CharSequence to check, may be null
* @param searchSeq the CharSequence to find, may be null
* @return the first index of the search CharSequence,
* -1 if no match or {@code null} string input
*/
public static int indexOf(CharSequence seq, CharSequence searchSeq) {
if (seq == null || searchSeq == null) {
return INDEX_NOT_FOUND;
}
return CharSequenceUtils.indexOf(seq, searchSeq, 0);
}
/**
* <p>Finds the first index within a CharSequence, handling {@code null}.
* This method uses {@link String#indexOf(String, int)} if possible.</p>
*
* <p>A {@code null} CharSequence will return {@code -1}.
* A negative start position is treated as zero.
* An empty ("") search CharSequence always matches.
* A start position greater than the string length only matches
* an empty search CharSequence.</p>
*
* <pre>
* StringUtils.indexOf(null, *, *) = -1
* StringUtils.indexOf(*, null, *) = -1
* StringUtils.indexOf("", "", 0) = 0
* StringUtils.indexOf("", *, 0) = -1 (except when * = "")
* StringUtils.indexOf("aabaabaa", "a", 0) = 0
* StringUtils.indexOf("aabaabaa", "b", 0) = 2
* StringUtils.indexOf("aabaabaa", "ab", 0) = 1
* StringUtils.indexOf("aabaabaa", "b", 3) = 5
* StringUtils.indexOf("aabaabaa", "b", 9) = -1
* StringUtils.indexOf("aabaabaa", "b", -1) = 2
* StringUtils.indexOf("aabaabaa", "", 2) = 2
* StringUtils.indexOf("abc", "", 9) = 3
* </pre>
*
* @param seq the CharSequence to check, may be null
* @param searchSeq the CharSequence to find, may be null
* @param startPos the start position, negative treated as zero
* @return the first index of the search CharSequence,
* -1 if no match or {@code null} string input
*/
public static int indexOf(CharSequence seq, CharSequence searchSeq, int startPos) {
if (seq == null || searchSeq == null) {
return INDEX_NOT_FOUND;
}
return CharSequenceUtils.indexOf(seq, searchSeq, startPos);
}
/**
* <p>Case in-sensitive find of the first index within a CharSequence.</p>
*
* <p>A {@code null} CharSequence will return {@code -1}.
* A negative start position is treated as zero.
* An empty ("") search CharSequence always matches.
* A start position greater than the string length only matches
* an empty search CharSequence.</p>
*
* <pre>
* StringUtils.indexOfIgnoreCase(null, *) = -1
* StringUtils.indexOfIgnoreCase(*, null) = -1
* StringUtils.indexOfIgnoreCase("", "") = 0
* StringUtils.indexOfIgnoreCase("aabaabaa", "a") = 0
* StringUtils.indexOfIgnoreCase("aabaabaa", "b") = 2
* StringUtils.indexOfIgnoreCase("aabaabaa", "ab") = 1
* </pre>
*
* @param str the CharSequence to check, may be null
* @param searchStr the CharSequence to find, may be null
* @return the first index of the search CharSequence,
* -1 if no match or {@code null} string input
*/
public static int indexOfIgnoreCase(CharSequence str, CharSequence searchStr) {
return indexOfIgnoreCase(str, searchStr, 0);
}
/**
* <p>Case in-sensitive find of the first index within a CharSequence
* from the specified position.</p>
*
* <p>A {@code null} CharSequence will return {@code -1}.
* A negative start position is treated as zero.
* An empty ("") search CharSequence always matches.
* A start position greater than the string length only matches
* an empty search CharSequence.</p>
*
* <pre>
* StringUtils.indexOfIgnoreCase(null, *, *) = -1
* StringUtils.indexOfIgnoreCase(*, null, *) = -1
* StringUtils.indexOfIgnoreCase("", "", 0) = 0
* StringUtils.indexOfIgnoreCase("aabaabaa", "A", 0) = 0
* StringUtils.indexOfIgnoreCase("aabaabaa", "B", 0) = 2
* StringUtils.indexOfIgnoreCase("aabaabaa", "AB", 0) = 1
* StringUtils.indexOfIgnoreCase("aabaabaa", "B", 3) = 5
* StringUtils.indexOfIgnoreCase("aabaabaa", "B", 9) = -1
* StringUtils.indexOfIgnoreCase("aabaabaa", "B", -1) = 2
* StringUtils.indexOfIgnoreCase("aabaabaa", "", 2) = 2
* StringUtils.indexOfIgnoreCase("abc", "", 9) = 3
* </pre>
*
* @param str the CharSequence to check, may be null
* @param searchStr the CharSequence to find, may be null
* @param startPos the start position, negative treated as zero
* @return the first index of the search CharSequence,
* -1 if no match or {@code null} string input
*/
public static int indexOfIgnoreCase(CharSequence str, CharSequence searchStr, int startPos) {
if (str == null || searchStr == null) {
return INDEX_NOT_FOUND;
}
if (startPos < 0) {
startPos = 0;
}
int endLimit = str.length() - searchStr.length() + 1;
if (startPos > endLimit) {
return INDEX_NOT_FOUND;
}
if (searchStr.length() == 0) {
return startPos;
}
for (int i = startPos; i < endLimit; i++) {
if (CharSequenceUtils.regionMatches(str, true, i, searchStr, 0, searchStr.length())) {
return i;
}
}
return INDEX_NOT_FOUND;
}
// LastIndexOf
//-----------------------------------------------------------------------
/**
* <p>Finds the last index within a CharSequence, handling {@code null}.
* This method uses {@link String#lastIndexOf(int)} if possible.</p>
*
* <p>A {@code null} or empty ("") CharSequence will return {@code -1}.</p>
*
* <pre>
* StringUtils.lastIndexOf(null, *) = -1
* StringUtils.lastIndexOf("", *) = -1
* StringUtils.lastIndexOf("aabaabaa", 'a') = 7
* StringUtils.lastIndexOf("aabaabaa", 'b') = 5
* </pre>
*
* @param seq the CharSequence to check, may be null
* @param searchChar the character to find
* @return the last index of the search character,
* -1 if no match or {@code null} string input
*/
public static int lastIndexOf(CharSequence seq, int searchChar) {
if (isEmpty(seq)) {
return INDEX_NOT_FOUND;
}
return CharSequenceUtils.lastIndexOf(seq, searchChar, seq.length());
}
/**
* <p>Finds the last index within a CharSequence from a start position,
* handling {@code null}.
* This method uses {@link String#lastIndexOf(int, int)} if possible.</p>
*
* <p>A {@code null} or empty ("") CharSequence will return {@code -1}.
* A negative start position returns {@code -1}.
* A start position greater than the string length searches the whole string.</p>
*
* <pre>
* StringUtils.lastIndexOf(null, *, *) = -1
* StringUtils.lastIndexOf("", *, *) = -1
* StringUtils.lastIndexOf("aabaabaa", 'b', 8) = 5
* StringUtils.lastIndexOf("aabaabaa", 'b', 4) = 2
* StringUtils.lastIndexOf("aabaabaa", 'b', 0) = -1
* StringUtils.lastIndexOf("aabaabaa", 'b', 9) = 5
* StringUtils.lastIndexOf("aabaabaa", 'b', -1) = -1
* StringUtils.lastIndexOf("aabaabaa", 'a', 0) = 0
* </pre>
*
* @param seq the CharSequence to check, may be null
* @param searchChar the character to find
* @param startPos the start position
* @return the last index of the search character,
* -1 if no match or {@code null} string input
*/
public static int lastIndexOf(CharSequence seq, int searchChar, int startPos) {
if (isEmpty(seq)) {
return INDEX_NOT_FOUND;
}
return CharSequenceUtils.lastIndexOf(seq, searchChar, startPos);
}
/**
* <p>Finds the last index within a CharSequence, handling {@code null}.
* This method uses {@link String#lastIndexOf(String)} if possible.</p>
*
* <p>A {@code null} CharSequence will return {@code -1}.</p>
*
* <pre>
* StringUtils.lastIndexOf(null, *) = -1
* StringUtils.lastIndexOf(*, null) = -1
* StringUtils.lastIndexOf("", "") = 0
* StringUtils.lastIndexOf("aabaabaa", "a") = 7
* StringUtils.lastIndexOf("aabaabaa", "b") = 5
* StringUtils.lastIndexOf("aabaabaa", "ab") = 4
* StringUtils.lastIndexOf("aabaabaa", "") = 8
* </pre>
*
* @param seq the CharSequence to check, may be null
* @param searchSeq the CharSequence to find, may be null
* @return the last index of the search String,
* -1 if no match or {@code null} string input
*/
public static int lastIndexOf(CharSequence seq, CharSequence searchSeq) {
if (seq == null || searchSeq == null) {
return INDEX_NOT_FOUND;
}
return CharSequenceUtils.lastIndexOf(seq, searchSeq, seq.length());
}
/**
* <p>Finds the first index within a CharSequence, handling {@code null}.
* This method uses {@link String#lastIndexOf(String, int)} if possible.</p>
*
* <p>A {@code null} CharSequence will return {@code -1}.
* A negative start position returns {@code -1}.
* An empty ("") search CharSequence always matches unless the start position is negative.
* A start position greater than the string length searches the whole string.</p>
*
* <pre>
* StringUtils.lastIndexOf(null, *, *) = -1
* StringUtils.lastIndexOf(*, null, *) = -1
* StringUtils.lastIndexOf("aabaabaa", "a", 8) = 7
* StringUtils.lastIndexOf("aabaabaa", "b", 8) = 5
* StringUtils.lastIndexOf("aabaabaa", "ab", 8) = 4
* StringUtils.lastIndexOf("aabaabaa", "b", 9) = 5
* StringUtils.lastIndexOf("aabaabaa", "b", -1) = -1
* StringUtils.lastIndexOf("aabaabaa", "a", 0) = 0
* StringUtils.lastIndexOf("aabaabaa", "b", 0) = -1
* </pre>
*
* @param seq the CharSequence to check, may be null
* @param searchSeq the CharSequence to find, may be null
* @param startPos the start position, negative treated as zero
* @return the first index of the search CharSequence,
* -1 if no match or {@code null} string input
*/
public static int lastIndexOf(CharSequence seq, CharSequence searchSeq, int startPos) {
if (seq == null || searchSeq == null) {
return INDEX_NOT_FOUND;
}
return CharSequenceUtils.lastIndexOf(seq, searchSeq, startPos);
}
/**
* <p>Case in-sensitive find of the last index within a CharSequence.</p>
*
* <p>A {@code null} CharSequence will return {@code -1}.
* A negative start position returns {@code -1}.
* An empty ("") search CharSequence always matches unless the start position is negative.
* A start position greater than the string length searches the whole string.</p>
*
* <pre>
* StringUtils.lastIndexOfIgnoreCase(null, *) = -1
* StringUtils.lastIndexOfIgnoreCase(*, null) = -1
* StringUtils.lastIndexOfIgnoreCase("aabaabaa", "A") = 7
* StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B") = 5
* StringUtils.lastIndexOfIgnoreCase("aabaabaa", "AB") = 4
* </pre>
*
* @param str the CharSequence to check, may be null
* @param searchStr the CharSequence to find, may be null
* @return the first index of the search CharSequence,
* -1 if no match or {@code null} string input
*/
public static int lastIndexOfIgnoreCase(CharSequence str, CharSequence searchStr) {
if (str == null || searchStr == null) {
return INDEX_NOT_FOUND;
}
return lastIndexOfIgnoreCase(str, searchStr, str.length());
}
/**
* <p>Case in-sensitive find of the last index within a CharSequence
* from the specified position.</p>
*
* <p>A {@code null} CharSequence will return {@code -1}.
* A negative start position returns {@code -1}.
* An empty ("") search CharSequence always matches unless the start position is negative.
* A start position greater than the string length searches the whole string.</p>
*
* <pre>
* StringUtils.lastIndexOfIgnoreCase(null, *, *) = -1
* StringUtils.lastIndexOfIgnoreCase(*, null, *) = -1
* StringUtils.lastIndexOfIgnoreCase("aabaabaa", "A", 8) = 7
* StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B", 8) = 5
* StringUtils.lastIndexOfIgnoreCase("aabaabaa", "AB", 8) = 4
* StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B", 9) = 5
* StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B", -1) = -1
* StringUtils.lastIndexOfIgnoreCase("aabaabaa", "A", 0) = 0
* StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B", 0) = -1
* </pre>
*
* @param str the CharSequence to check, may be null
* @param searchStr the CharSequence to find, may be null
* @param startPos the start position
* @return the first index of the search CharSequence,
* -1 if no match or {@code null} input
*/
public static int lastIndexOfIgnoreCase(CharSequence str, CharSequence searchStr, int startPos) {
if (str == null || searchStr == null) {
return INDEX_NOT_FOUND;
}
if (startPos > str.length() - searchStr.length()) {
startPos = str.length() - searchStr.length();
}
if (startPos < 0) {
return INDEX_NOT_FOUND;
}
if (searchStr.length() == 0) {
return startPos;
}
for (int i = startPos; i >= 0; i--) {
if (CharSequenceUtils.regionMatches(str, true, i, searchStr, 0, searchStr.length())) {
return i;
}
}
return INDEX_NOT_FOUND;
}
// Contains
//-----------------------------------------------------------------------
/**
* <p>Checks if CharSequence contains a search character, handling {@code null}.
* This method uses {@link String#indexOf(int)} if possible.</p>
*
* <p>A {@code null} or empty ("") CharSequence will return {@code false}.</p>
*
* <pre>
* StringUtils.contains(null, *) = false
* StringUtils.contains("", *) = false
* StringUtils.contains("abc", 'a') = true
* StringUtils.contains("abc", 'z') = false
* </pre>
*
* @param seq the CharSequence to check, may be null
* @param searchChar the character to find
* @return true if the CharSequence contains the search character,
* false if not or {@code null} string input
*/
public static boolean contains(CharSequence seq, int searchChar) {
if (isEmpty(seq)) {
return false;
}
return CharSequenceUtils.indexOf(seq, searchChar, 0) >= 0;
}
/**
* <p>Checks if CharSequence contains a search CharSequence, handling {@code null}.
* This method uses {@link String#indexOf(String)} if possible.</p>
*
* <p>A {@code null} CharSequence will return {@code false}.</p>
*
* <pre>
* StringUtils.contains(null, *) = false
* StringUtils.contains(*, null) = false
* StringUtils.contains("", "") = true
* StringUtils.contains("abc", "") = true
* StringUtils.contains("abc", "a") = true
* StringUtils.contains("abc", "z") = false
* </pre>
*
* @param seq the CharSequence to check, may be null
* @param searchSeq the CharSequence to find, may be null
* @return true if the CharSequence contains the search CharSequence,
* false if not or {@code null} string input
*/
public static boolean contains(CharSequence seq, CharSequence searchSeq) {
if (seq == null || searchSeq == null) {
return false;
}
return CharSequenceUtils.indexOf(seq, searchSeq, 0) >= 0;
}
/**
* <p>Checks if CharSequence contains a search CharSequence irrespective of case,
* handling {@code null}. Case-insensitivity is defined as by
* {@link String#equalsIgnoreCase(String)}.
*
* <p>A {@code null} CharSequence will return {@code false}.</p>
*
* <pre>
* StringUtils.contains(null, *) = false
* StringUtils.contains(*, null) = false
* StringUtils.contains("", "") = true
* StringUtils.contains("abc", "") = true
* StringUtils.contains("abc", "a") = true
* StringUtils.contains("abc", "z") = false
* StringUtils.contains("abc", "A") = true
* StringUtils.contains("abc", "Z") = false
* </pre>
*
* @param str the CharSequence to check, may be null
* @param searchStr the CharSequence to find, may be null
* @return true if the CharSequence contains the search CharSequence irrespective of
* case or false if not or {@code null} string input
*/
public static boolean containsIgnoreCase(CharSequence str, CharSequence searchStr) {
if (str == null || searchStr == null) {
return false;
}
int len = searchStr.length();
int max = str.length() - len;
for (int i = 0; i <= max; i++) {
if (CharSequenceUtils.regionMatches(str, true, i, searchStr, 0, len)) {
return true;
}
}
return false;
}
// Substring
//-----------------------------------------------------------------------
/**
* <p>Gets a substring from the specified String avoiding exceptions.</p>
*
* <p>A negative start position can be used to start {@code n}
* characters from the end of the String.</p>
*
* <p>A {@code null} String will return {@code null}.
* An empty ("") String will return "".</p>
*
* <pre>
* StringUtils.substring(null, *) = null
* StringUtils.substring("", *) = ""
* StringUtils.substring("abc", 0) = "abc"
* StringUtils.substring("abc", 2) = "c"
* StringUtils.substring("abc", 4) = ""
* StringUtils.substring("abc", -2) = "bc"
* StringUtils.substring("abc", -4) = "abc"
* </pre>
*
* @param str the String to get the substring from, may be null
* @param start the position to start from, negative means
* count back from the end of the String by this many characters
* @return substring from start position, {@code null} if null String input
*/
public static String substring(String str, int start) {
if (str == null) {
return null;
}
// handle negatives, which means last n characters
if (start < 0) {
start = str.length() + start; // remember start is negative
}
if (start < 0) {
start = 0;
}
if (start > str.length()) {
return EMPTY;
}
return str.substring(start);
}
/**
* <p>Gets a substring from the specified String avoiding exceptions.</p>
*
* <p>A negative start position can be used to start/end {@code n}
* characters from the end of the String.</p>
*
* <p>The returned substring starts with the character in the {@code start}
* position and ends before the {@code end} position. All position counting is
* zero-based -- i.e., to start at the beginning of the string use
* {@code start = 0}. Negative start and end positions can be used to
* specify offsets relative to the end of the String.</p>
*
* <p>If {@code start} is not strictly to the left of {@code end}, ""
* is returned.</p>
*
* <pre>
* StringUtils.substring(null, *, *) = null
* StringUtils.substring("", * , *) = "";
* StringUtils.substring("abc", 0, 2) = "ab"
* StringUtils.substring("abc", 2, 0) = ""
* StringUtils.substring("abc", 2, 4) = "c"
* StringUtils.substring("abc", 4, 6) = ""
* StringUtils.substring("abc", 2, 2) = ""
* StringUtils.substring("abc", -2, -1) = "b"
* StringUtils.substring("abc", -4, 2) = "ab"
* </pre>
*
* @param str the String to get the substring from, may be null
* @param start the position to start from, negative means
* count back from the end of the String by this many characters
* @param end the position to end at (exclusive), negative means
* count back from the end of the String by this many characters
* @return substring from start position to end position,
* {@code null} if null String input
*/
public static String substring(String str, int start, int end) {
if (str == null) {
return null;
}
// handle negatives
if (end < 0) {
end = str.length() + end; // remember end is negative
}
if (start < 0) {
start = str.length() + start; // remember start is negative
}
// check length next
if (end > str.length()) {
end = str.length();
}
// if start is greater than end, return ""
if (start > end) {
return EMPTY;
}
if (start < 0) {
start = 0;
}
if (end < 0) {
end = 0;
}
return str.substring(start, end);
}
// Left/Right/Mid
//-----------------------------------------------------------------------
/**
* <p>Gets the leftmost {@code len} characters of a String.</p>
*
* <p>If {@code len} characters are not available, or the
* String is {@code null}, the String will be returned without
* an exception. An empty String is returned if len is negative.</p>
*
* <pre>
* StringUtils.left(null, *) = null
* StringUtils.left(*, -ve) = ""
* StringUtils.left("", *) = ""
* StringUtils.left("abc", 0) = ""
* StringUtils.left("abc", 2) = "ab"
* StringUtils.left("abc", 4) = "abc"
* </pre>
*
* @param str the String to get the leftmost characters from, may be null
* @param len the length of the required String
* @return the leftmost characters, {@code null} if null String input
*/
public static String left(String str, int len) {
if (str == null) {
return null;
}
if (len < 0) {
return EMPTY;
}
if (str.length() <= len) {
return str;
}
return str.substring(0, len);
}
/**
* <p>Gets the rightmost {@code len} characters of a String.</p>
*
* <p>If {@code len} characters are not available, or the String
* is {@code null}, the String will be returned without an
* an exception. An empty String is returned if len is negative.</p>
*
* <pre>
* StringUtils.right(null, *) = null
* StringUtils.right(*, -ve) = ""
* StringUtils.right("", *) = ""
* StringUtils.right("abc", 0) = ""
* StringUtils.right("abc", 2) = "bc"
* StringUtils.right("abc", 4) = "abc"
* </pre>
*
* @param str the String to get the rightmost characters from, may be null
* @param len the length of the required String
* @return the rightmost characters, {@code null} if null String input
*/
public static String right(String str, int len) {
if (str == null) {
return null;
}
if (len < 0) {
return EMPTY;
}
if (str.length() <= len) {
return str;
}
return str.substring(str.length() - len);
}
/**
* <p>Gets {@code len} characters from the middle of a String.</p>
*
* <p>If {@code len} characters are not available, the remainder
* of the String will be returned without an exception. If the
* String is {@code null}, {@code null} will be returned.
* An empty String is returned if len is negative or exceeds the
* length of {@code str}.</p>
*
* <pre>
* StringUtils.mid(null, *, *) = null
* StringUtils.mid(*, *, -ve) = ""
* StringUtils.mid("", 0, *) = ""
* StringUtils.mid("abc", 0, 2) = "ab"
* StringUtils.mid("abc", 0, 4) = "abc"
* StringUtils.mid("abc", 2, 4) = "c"
* StringUtils.mid("abc", 4, 2) = ""
* StringUtils.mid("abc", -2, 2) = "ab"
* </pre>
*
* @param str the String to get the characters from, may be null
* @param pos the position to start from, negative treated as zero
* @param len the length of the required String
* @return the middle characters, {@code null} if null String input
*/
public static String mid(String str, int pos, int len) {
if (str == null) {
return null;
}
if (len < 0 || pos > str.length()) {
return EMPTY;
}
if (pos < 0) {
pos = 0;
}
if (str.length() <= pos + len) {
return str.substring(pos);
}
return str.substring(pos, pos + len);
}
// SubStringAfter/SubStringBefore
//-----------------------------------------------------------------------
/**
* <p>Gets the substring before the first occurrence of a separator.
* The separator is not returned.</p>
*
* <p>A {@code null} string input will return {@code null}.
* An empty ("") string input will return the empty string.
* A {@code null} separator will return the input string.</p>
*
* <p>If nothing is found, the string input is returned.</p>
*
* <pre>
* StringUtils.substringBefore(null, *) = null
* StringUtils.substringBefore("", *) = ""
* StringUtils.substringBefore("abc", "a") = ""
* StringUtils.substringBefore("abcba", "b") = "a"
* StringUtils.substringBefore("abc", "c") = "ab"
* StringUtils.substringBefore("abc", "d") = "abc"
* StringUtils.substringBefore("abc", "") = ""
* StringUtils.substringBefore("abc", null) = "abc"
* </pre>
*
* @param str the String to get a substring from, may be null
* @param separator the String to search for, may be null
* @return the substring before the first occurrence of the separator,
* {@code null} if null String input
*/
public static String substringBefore(String str, String separator) {
if (isEmpty(str) || separator == null) {
return str;
}
if (separator.length() == 0) {
return EMPTY;
}
int pos = str.indexOf(separator);
if (pos == INDEX_NOT_FOUND) {
return str;
}
return str.substring(0, pos);
}
/**
* <p>Gets the substring after the first occurrence of a separator.
* The separator is not returned.</p>
*
* <p>A {@code null} string input will return {@code null}.
* An empty ("") string input will return the empty string.
* A {@code null} separator will return the empty string if the
* input string is not {@code null}.</p>
*
* <p>If nothing is found, the empty string is returned.</p>
*
* <pre>
* StringUtils.substringAfter(null, *) = null
* StringUtils.substringAfter("", *) = ""
* StringUtils.substringAfter(*, null) = ""
* StringUtils.substringAfter("abc", "a") = "bc"
* StringUtils.substringAfter("abcba", "b") = "cba"
* StringUtils.substringAfter("abc", "c") = ""
* StringUtils.substringAfter("abc", "d") = ""
* StringUtils.substringAfter("abc", "") = "abc"
* </pre>
*
* @param str the String to get a substring from, may be null
* @param separator the String to search for, may be null
* @return the substring after the first occurrence of the separator,
* {@code null} if null String input
*/
public static String substringAfter(String str, String separator) {
if (isEmpty(str)) {
return str;
}
if (separator == null) {
return EMPTY;
}
int pos = str.indexOf(separator);
if (pos == INDEX_NOT_FOUND) {
return EMPTY;
}
return str.substring(pos + separator.length());
}
/**
* <p>Gets the substring before the last occurrence of a separator.
* The separator is not returned.</p>
*
* <p>A {@code null} string input will return {@code null}.
* An empty ("") string input will return the empty string.
* An empty or {@code null} separator will return the input string.</p>
*
* <p>If nothing is found, the string input is returned.</p>
*
* <pre>
* StringUtils.substringBeforeLast(null, *) = null
* StringUtils.substringBeforeLast("", *) = ""
* StringUtils.substringBeforeLast("abcba", "b") = "abc"
* StringUtils.substringBeforeLast("abc", "c") = "ab"
* StringUtils.substringBeforeLast("a", "a") = ""
* StringUtils.substringBeforeLast("a", "z") = "a"
* StringUtils.substringBeforeLast("a", null) = "a"
* StringUtils.substringBeforeLast("a", "") = "a"
* </pre>
*
* @param str the String to get a substring from, may be null
* @param separator the String to search for, may be null
* @return the substring before the last occurrence of the separator,
* {@code null} if null String input
*/
public static String substringBeforeLast(String str, String separator) {
if (isEmpty(str) || isEmpty(separator)) {
return str;
}
int pos = str.lastIndexOf(separator);
if (pos == INDEX_NOT_FOUND) {
return str;
}
return str.substring(0, pos);
}
/**
* <p>Gets the substring after the last occurrence of a separator.
* The separator is not returned.</p>
*
* <p>A {@code null} string input will return {@code null}.
* An empty ("") string input will return the empty string.
* An empty or {@code null} separator will return the empty string if
* the input string is not {@code null}.</p>
*
* <p>If nothing is found, the empty string is returned.</p>
*
* <pre>
* StringUtils.substringAfterLast(null, *) = null
* StringUtils.substringAfterLast("", *) = ""
* StringUtils.substringAfterLast(*, "") = ""
* StringUtils.substringAfterLast(*, null) = ""
* StringUtils.substringAfterLast("abc", "a") = "bc"
* StringUtils.substringAfterLast("abcba", "b") = "a"
* StringUtils.substringAfterLast("abc", "c") = ""
* StringUtils.substringAfterLast("a", "a") = ""
* StringUtils.substringAfterLast("a", "z") = ""
* </pre>
*
* @param str the String to get a substring from, may be null
* @param separator the String to search for, may be null
* @return the substring after the last occurrence of the separator,
* {@code null} if null String input
*/
public static String substringAfterLast(String str, String separator) {
if (isEmpty(str)) {
return str;
}
if (isEmpty(separator)) {
return EMPTY;
}
int pos = str.lastIndexOf(separator);
if (pos == INDEX_NOT_FOUND || pos == str.length() - separator.length()) {
return EMPTY;
}
return str.substring(pos + separator.length());
}
// Substring between
//-----------------------------------------------------------------------
/**
* <p>Gets the String that is nested in between two instances of the
* same String.</p>
*
* <p>A {@code null} input String returns {@code null}.
* A {@code null} tag returns {@code null}.</p>
*
* <pre>
* StringUtils.substringBetween(null, *) = null
* StringUtils.substringBetween("", "") = ""
* StringUtils.substringBetween("", "tag") = null
* StringUtils.substringBetween("tagabctag", null) = null
* StringUtils.substringBetween("tagabctag", "") = ""
* StringUtils.substringBetween("tagabctag", "tag") = "abc"
* </pre>
*
* @param str the String containing the substring, may be null
* @param tag the String before and after the substring, may be null
* @return the substring, {@code null} if no match
*/
public static String substringBetween(String str, String tag) {
return substringBetween(str, tag, tag);
}
/**
* <p>Gets the String that is nested in between two Strings.
* Only the first match is returned.</p>
*
* <p>A {@code null} input String returns {@code null}.
* A {@code null} open/close returns {@code null} (no match).
* An empty ("") open and close returns an empty string.</p>
*
* <pre>
* StringUtils.substringBetween("wx[b]yz", "[", "]") = "b"
* StringUtils.substringBetween(null, *, *) = null
* StringUtils.substringBetween(*, null, *) = null
* StringUtils.substringBetween(*, *, null) = null
* StringUtils.substringBetween("", "", "") = ""
* StringUtils.substringBetween("", "", "]") = null
* StringUtils.substringBetween("", "[", "]") = null
* StringUtils.substringBetween("yabcz", "", "") = ""
* StringUtils.substringBetween("yabcz", "y", "z") = "abc"
* StringUtils.substringBetween("yabczyabcz", "y", "z") = "abc"
* </pre>
*
* @param str the String containing the substring, may be null
* @param open the String before the substring, may be null
* @param close the String after the substring, may be null
* @return the substring, {@code null} if no match
*/
public static String substringBetween(String str, String open, String close) {
if (str == null || open == null || close == null) {
return null;
}
int start = str.indexOf(open);
if (start != INDEX_NOT_FOUND) {
int end = str.indexOf(close, start + open.length());
if (end != INDEX_NOT_FOUND) {
return str.substring(start + open.length(), end);
}
}
return null;
}
/**
* <p>Searches a String for substrings delimited by a start and end tag,
* returning all matching substrings in an array.</p>
*
* <p>A {@code null} input String returns {@code null}.
* A {@code null} open/close returns {@code null} (no match).
* An empty ("") open/close returns {@code null} (no match).</p>
*
* <pre>
* StringUtils.substringsBetween("[a][b][c]", "[", "]") = ["a","b","c"]
* StringUtils.substringsBetween(null, *, *) = null
* StringUtils.substringsBetween(*, null, *) = null
* StringUtils.substringsBetween(*, *, null) = null
* StringUtils.substringsBetween("", "[", "]") = []
* </pre>
*
* @param str the String containing the substrings, null returns null, empty returns empty
* @param open the String identifying the start of the substring, empty returns null
* @param close the String identifying the end of the substring, empty returns null
*/
public static String[] substringsBetween(String str, String open, String close) {
if (str == null || isEmpty(open) || isEmpty(close)) {
return null;
}
int strLen = str.length();
if (strLen == 0) {
return ArrayUtils.EMPTY_STRING_ARRAY;
}
int closeLen = close.length();
int openLen = open.length();
List<String> list = new ArrayList<String>();
int pos = 0;
while (pos < strLen - closeLen) {
int start = str.indexOf(open, pos);
if (start < 0) {
break;
}
start += openLen;
int end = str.indexOf(close, start);
if (end < 0) {
break;
}
list.add(str.substring(start, end));
pos = end + closeLen;
}
if (list.isEmpty()) {
return null;
}
return list.toArray(new String [list.size()]);
}
// Nested extraction
//-----------------------------------------------------------------------
// Splitting
//-----------------------------------------------------------------------
/**
* <p>Splits the provided text into an array, using whitespace as the
* separator.
* Whitespace is defined by {@link Character#isWhitespace(char)}.</p>
*
* <p>The separator is not included in the returned String array.
* Adjacent separators are treated as one separator.
* For more control over the split use the StrTokenizer class.</p>
*
* <p>A {@code null} input String returns {@code null}.</p>
*
* <pre>
* StringUtils.split(null) = null
* StringUtils.split("") = []
* StringUtils.split("abc def") = ["abc", "def"]
* StringUtils.split("abc def") = ["abc", "def"]
* StringUtils.split(" abc ") = ["abc"]
* </pre>
*
* @param str the String to parse, may be null
* @return an array of parsed Strings, {@code null} if null String input
*/
public static String[] split(String str) {
return split(str, null, -1);
}
/**
* <p>Splits the provided text into an array, separator specified.
* This is an alternative to using StringTokenizer.</p>
*
* <p>The separator is not included in the returned String array.
* Adjacent separators are treated as one separator.
* For more control over the split use the StrTokenizer class.</p>
*
* <p>A {@code null} input String returns {@code null}.</p>
*
* <pre>
* StringUtils.split(null, *) = null
* StringUtils.split("", *) = []
* StringUtils.split("a.b.c", '.') = ["a", "b", "c"]
* StringUtils.split("a.b.c.", '.') = ["a", "b", "c"]
* StringUtils.split("a..b.c", '.') = ["a", "b", "c"]
* StringUtils.split("a:b:c", '.') = ["a:b:c"]
* StringUtils.split("a b c", ' ') = ["a", "b", "c"]
* </pre>
*
* @param str the String to parse, may be null
* @param separatorChar the character used as the delimiter
* @return an array of parsed Strings, {@code null} if null String input
*/
public static String[] split(String str, char separatorChar) {
return splitWorker(str, separatorChar, false);
}
/**
* <p>Splits the provided text into an array, separators specified.
* This is an alternative to using StringTokenizer.</p>
*
* <p>The separator is not included in the returned String array.
* Adjacent separators are treated as one separator.
* For more control over the split use the StrTokenizer class.</p>
*
* <p>A {@code null} input String returns {@code null}.
* A {@code null} separatorChars splits on whitespace.</p>
*
* <pre>
* StringUtils.split(null, *) = null
* StringUtils.split("", *) = []
* StringUtils.split("abc def", null) = ["abc", "def"]
* StringUtils.split("abc def", " ") = ["abc", "def"]
* StringUtils.split("abc def", " ") = ["abc", "def"]
* StringUtils.split("ab:cd:ef", ":") = ["ab", "cd", "ef"]
* </pre>
*
* @param str the String to parse, may be null
* @param separatorChars the characters used as the delimiters,
* {@code null} splits on whitespace
* @return an array of parsed Strings, {@code null} if null String input
*/
public static String[] split(String str, String separatorChars) {
return splitWorker(str, separatorChars, -1, false);
}
/**
* <p>Splits the provided text into an array with a maximum length,
* separators specified.</p>
*
* <p>The separator is not included in the returned String array.
* Adjacent separators are treated as one separator.</p>
*
* <p>A {@code null} input String returns {@code null}.
* A {@code null} separatorChars splits on whitespace.</p>
*
* <p>If more than {@code max} delimited substrings are found, the last
* returned string includes all characters after the first {@code max - 1}
* returned strings (including separator characters).</p>
*
* <pre>
* StringUtils.split(null, *, *) = null
* StringUtils.split("", *, *) = []
* StringUtils.split("ab de fg", null, 0) = ["ab", "cd", "ef"]
* StringUtils.split("ab de fg", null, 0) = ["ab", "cd", "ef"]
* StringUtils.split("ab:cd:ef", ":", 0) = ["ab", "cd", "ef"]
* StringUtils.split("ab:cd:ef", ":", 2) = ["ab", "cd:ef"]
* </pre>
*
* @param str the String to parse, may be null
* @param separatorChars the characters used as the delimiters,
* {@code null} splits on whitespace
* @param max the maximum number of elements to include in the
* array. A zero or negative value implies no limit
* @return an array of parsed Strings, {@code null} if null String input
*/
public static String[] split(String str, String separatorChars, int max) {
return splitWorker(str, separatorChars, max, false);
}
/**
* <p>Splits the provided text into an array, separator string specified.</p>
*
* <p>The separator(s) will not be included in the returned String array.
* Adjacent separators are treated as one separator.</p>
*
* <p>A {@code null} input String returns {@code null}.
* A {@code null} separator splits on whitespace.</p>
*
* <pre>
* StringUtils.splitByWholeSeparator(null, *) = null
* StringUtils.splitByWholeSeparator("", *) = []
* StringUtils.splitByWholeSeparator("ab de fg", null) = ["ab", "de", "fg"]
* StringUtils.splitByWholeSeparator("ab de fg", null) = ["ab", "de", "fg"]
* StringUtils.splitByWholeSeparator("ab:cd:ef", ":") = ["ab", "cd", "ef"]
* StringUtils.splitByWholeSeparator("ab-!-cd-!-ef", "-!-") = ["ab", "cd", "ef"]
* </pre>
*
* @param str the String to parse, may be null
* @param separator String containing the String to be used as a delimiter,
* {@code null} splits on whitespace
* @return an array of parsed Strings, {@code null} if null String was input
*/
public static String[] splitByWholeSeparator(String str, String separator) {
return splitByWholeSeparatorWorker( str, separator, -1, false ) ;
}
/**
* <p>Splits the provided text into an array, separator string specified.
* Returns a maximum of {@code max} substrings.</p>
*
* <p>The separator(s) will not be included in the returned String array.
* Adjacent separators are treated as one separator.</p>
*
* <p>A {@code null} input String returns {@code null}.
* A {@code null} separator splits on whitespace.</p>
*
* <pre>
* StringUtils.splitByWholeSeparator(null, *, *) = null
* StringUtils.splitByWholeSeparator("", *, *) = []
* StringUtils.splitByWholeSeparator("ab de fg", null, 0) = ["ab", "de", "fg"]
* StringUtils.splitByWholeSeparator("ab de fg", null, 0) = ["ab", "de", "fg"]
* StringUtils.splitByWholeSeparator("ab:cd:ef", ":", 2) = ["ab", "cd:ef"]
* StringUtils.splitByWholeSeparator("ab-!-cd-!-ef", "-!-", 5) = ["ab", "cd", "ef"]
* StringUtils.splitByWholeSeparator("ab-!-cd-!-ef", "-!-", 2) = ["ab", "cd-!-ef"]
* </pre>
*
* @param str the String to parse, may be null
* @param separator String containing the String to be used as a delimiter,
* {@code null} splits on whitespace
* @param max the maximum number of elements to include in the returned
* array. A zero or negative value implies no limit.
* @return an array of parsed Strings, {@code null} if null String was input
*/
public static String[] splitByWholeSeparator( String str, String separator, int max ) {
return splitByWholeSeparatorWorker(str, separator, max, false);
}
/**
* <p>Splits the provided text into an array, separator string specified. </p>
*
* <p>The separator is not included in the returned String array.
* Adjacent separators are treated as separators for empty tokens.
* For more control over the split use the StrTokenizer class.</p>
*
* <p>A {@code null} input String returns {@code null}.
* A {@code null} separator splits on whitespace.</p>
*
* <pre>
* StringUtils.splitByWholeSeparatorPreserveAllTokens(null, *) = null
* StringUtils.splitByWholeSeparatorPreserveAllTokens("", *) = []
* StringUtils.splitByWholeSeparatorPreserveAllTokens("ab de fg", null) = ["ab", "de", "fg"]
* StringUtils.splitByWholeSeparatorPreserveAllTokens("ab de fg", null) = ["ab", "", "", "de", "fg"]
* StringUtils.splitByWholeSeparatorPreserveAllTokens("ab:cd:ef", ":") = ["ab", "cd", "ef"]
* StringUtils.splitByWholeSeparatorPreserveAllTokens("ab-!-cd-!-ef", "-!-") = ["ab", "cd", "ef"]
* </pre>
*
* @param str the String to parse, may be null
* @param separator String containing the String to be used as a delimiter,
* {@code null} splits on whitespace
* @return an array of parsed Strings, {@code null} if null String was input
*/
public static String[] splitByWholeSeparatorPreserveAllTokens(String str, String separator) {
return splitByWholeSeparatorWorker(str, separator, -1, true);
}
/**
* <p>Splits the provided text into an array, separator string specified.
* Returns a maximum of {@code max} substrings.</p>
*
* <p>The separator is not included in the returned String array.
* Adjacent separators are treated as separators for empty tokens.
* For more control over the split use the StrTokenizer class.</p>
*
* <p>A {@code null} input String returns {@code null}.
* A {@code null} separator splits on whitespace.</p>
*
* <pre>
* StringUtils.splitByWholeSeparatorPreserveAllTokens(null, *, *) = null
* StringUtils.splitByWholeSeparatorPreserveAllTokens("", *, *) = []
* StringUtils.splitByWholeSeparatorPreserveAllTokens("ab de fg", null, 0) = ["ab", "de", "fg"]
* StringUtils.splitByWholeSeparatorPreserveAllTokens("ab de fg", null, 0) = ["ab", "", "", "de", "fg"]
* StringUtils.splitByWholeSeparatorPreserveAllTokens("ab:cd:ef", ":", 2) = ["ab", "cd:ef"]
* StringUtils.splitByWholeSeparatorPreserveAllTokens("ab-!-cd-!-ef", "-!-", 5) = ["ab", "cd", "ef"]
* StringUtils.splitByWholeSeparatorPreserveAllTokens("ab-!-cd-!-ef", "-!-", 2) = ["ab", "cd-!-ef"]
* </pre>
*
* @param str the String to parse, may be null
* @param separator String containing the String to be used as a delimiter,
* {@code null} splits on whitespace
* @param max the maximum number of elements to include in the returned
* array. A zero or negative value implies no limit.
* @return an array of parsed Strings, {@code null} if null String was input
*/
public static String[] splitByWholeSeparatorPreserveAllTokens(String str, String separator, int max) {
return splitByWholeSeparatorWorker(str, separator, max, true);
}
/**
* Performs the logic for the {@code splitByWholeSeparatorPreserveAllTokens} methods.
*
* @param str the String to parse, may be {@code null}
* @param separator String containing the String to be used as a delimiter,
* {@code null} splits on whitespace
* @param max the maximum number of elements to include in the returned
* array. A zero or negative value implies no limit.
* @param preserveAllTokens if {@code true}, adjacent separators are
* treated as empty token separators; if {@code false}, adjacent
* separators are treated as one separator.
* @return an array of parsed Strings, {@code null} if null String input
*/
private static String[] splitByWholeSeparatorWorker(
String str, String separator, int max, boolean preserveAllTokens) {
if (str == null) {
return null;
}
int len = str.length();
if (len == 0) {
return ArrayUtils.EMPTY_STRING_ARRAY;
}
if (separator == null || EMPTY.equals(separator)) {
// Split on whitespace.
return splitWorker(str, null, max, preserveAllTokens);
}
int separatorLength = separator.length();
ArrayList<String> substrings = new ArrayList<String>();
int numberOfSubstrings = 0;
int beg = 0;
int end = 0;
while (end < len) {
end = str.indexOf(separator, beg);
if (end > -1) {
if (end > beg) {
numberOfSubstrings += 1;
if (numberOfSubstrings == max) {
end = len;
substrings.add(str.substring(beg));
} else {
// The following is OK, because String.substring( beg, end ) excludes
// the character at the position 'end'.
substrings.add(str.substring(beg, end));
// Set the starting point for the next search.
// The following is equivalent to beg = end + (separatorLength - 1) + 1,
// which is the right calculation:
beg = end + separatorLength;
}
} else {
// We found a consecutive occurrence of the separator, so skip it.
if (preserveAllTokens) {
numberOfSubstrings += 1;
if (numberOfSubstrings == max) {
end = len;
substrings.add(str.substring(beg));
} else {
substrings.add(EMPTY);
}
}
beg = end + separatorLength;
}
} else {
// String.substring( beg ) goes from 'beg' to the end of the String.
substrings.add(str.substring(beg));
end = len;
}
}
return substrings.toArray(new String[substrings.size()]);
}
// -----------------------------------------------------------------------
/**
* <p>Splits the provided text into an array, using whitespace as the
* separator, preserving all tokens, including empty tokens created by
* adjacent separators. This is an alternative to using StringTokenizer.
* Whitespace is defined by {@link Character#isWhitespace(char)}.</p>
*
* <p>The separator is not included in the returned String array.
* Adjacent separators are treated as separators for empty tokens.
* For more control over the split use the StrTokenizer class.</p>
*
* <p>A {@code null} input String returns {@code null}.</p>
*
* <pre>
* StringUtils.splitPreserveAllTokens(null) = null
* StringUtils.splitPreserveAllTokens("") = []
* StringUtils.splitPreserveAllTokens("abc def") = ["abc", "def"]
* StringUtils.splitPreserveAllTokens("abc def") = ["abc", "", "def"]
* StringUtils.splitPreserveAllTokens(" abc ") = ["", "abc", ""]
* </pre>
*
* @param str the String to parse, may be {@code null}
* @return an array of parsed Strings, {@code null} if null String input
*/
public static String[] splitPreserveAllTokens(String str) {
return splitWorker(str, null, -1, true);
}
/**
* <p>Splits the provided text into an array, separator specified,
* preserving all tokens, including empty tokens created by adjacent
* separators. This is an alternative to using StringTokenizer.</p>
*
* <p>The separator is not included in the returned String array.
* Adjacent separators are treated as separators for empty tokens.
* For more control over the split use the StrTokenizer class.</p>
*
* <p>A {@code null} input String returns {@code null}.</p>
*
* <pre>
* StringUtils.splitPreserveAllTokens(null, *) = null
* StringUtils.splitPreserveAllTokens("", *) = []
* StringUtils.splitPreserveAllTokens("a.b.c", '.') = ["a", "b", "c"]
* StringUtils.splitPreserveAllTokens("a..b.c", '.') = ["a", "", "b", "c"]
* StringUtils.splitPreserveAllTokens("a:b:c", '.') = ["a:b:c"]
* StringUtils.splitPreserveAllTokens("a\tb\nc", null) = ["a", "b", "c"]
* StringUtils.splitPreserveAllTokens("a b c", ' ') = ["a", "b", "c"]
* StringUtils.splitPreserveAllTokens("a b c ", ' ') = ["a", "b", "c", ""]
* StringUtils.splitPreserveAllTokens("a b c ", ' ') = ["a", "b", "c", "", ""]
* StringUtils.splitPreserveAllTokens(" a b c", ' ') = ["", a", "b", "c"]
* StringUtils.splitPreserveAllTokens(" a b c", ' ') = ["", "", a", "b", "c"]
* StringUtils.splitPreserveAllTokens(" a b c ", ' ') = ["", a", "b", "c", ""]
* </pre>
*
* @param str the String to parse, may be {@code null}
* @param separatorChar the character used as the delimiter,
* {@code null} splits on whitespace
* @return an array of parsed Strings, {@code null} if null String input
*/
public static String[] splitPreserveAllTokens(String str, char separatorChar) {
return splitWorker(str, separatorChar, true);
}
/**
* Performs the logic for the {@code split} and
* {@code splitPreserveAllTokens} methods that do not return a
* maximum array length.
*
* @param str the String to parse, may be {@code null}
* @param separatorChar the separate character
* @param preserveAllTokens if {@code true}, adjacent separators are
* treated as empty token separators; if {@code false}, adjacent
* separators are treated as one separator.
* @return an array of parsed Strings, {@code null} if null String input
*/
private static String[] splitWorker(String str, char separatorChar, boolean preserveAllTokens) {
// Performance tuned for 2.0 (JDK1.4)
if (str == null) {
return null;
}
int len = str.length();
if (len == 0) {
return ArrayUtils.EMPTY_STRING_ARRAY;
}
List<String> list = new ArrayList<String>();
int i = 0, start = 0;
boolean match = false;
boolean lastMatch = false;
while (i < len) {
if (str.charAt(i) == separatorChar) {
if (match || preserveAllTokens) {
list.add(str.substring(start, i));
match = false;
lastMatch = true;
}
start = ++i;
continue;
}
lastMatch = false;
match = true;
i++;
}
if (match || preserveAllTokens && lastMatch) {
list.add(str.substring(start, i));
}
return list.toArray(new String[list.size()]);
}
/**
* <p>Splits the provided text into an array, separators specified,
* preserving all tokens, including empty tokens created by adjacent
* separators. This is an alternative to using StringTokenizer.</p>
*
* <p>The separator is not included in the returned String array.
* Adjacent separators are treated as separators for empty tokens.
* For more control over the split use the StrTokenizer class.</p>
*
* <p>A {@code null} input String returns {@code null}.
* A {@code null} separatorChars splits on whitespace.</p>
*
* <pre>
* StringUtils.splitPreserveAllTokens(null, *) = null
* StringUtils.splitPreserveAllTokens("", *) = []
* StringUtils.splitPreserveAllTokens("abc def", null) = ["abc", "def"]
* StringUtils.splitPreserveAllTokens("abc def", " ") = ["abc", "def"]
* StringUtils.splitPreserveAllTokens("abc def", " ") = ["abc", "", def"]
* StringUtils.splitPreserveAllTokens("ab:cd:ef", ":") = ["ab", "cd", "ef"]
* StringUtils.splitPreserveAllTokens("ab:cd:ef:", ":") = ["ab", "cd", "ef", ""]
* StringUtils.splitPreserveAllTokens("ab:cd:ef::", ":") = ["ab", "cd", "ef", "", ""]
* StringUtils.splitPreserveAllTokens("ab::cd:ef", ":") = ["ab", "", cd", "ef"]
* StringUtils.splitPreserveAllTokens(":cd:ef", ":") = ["", cd", "ef"]
* StringUtils.splitPreserveAllTokens("::cd:ef", ":") = ["", "", cd", "ef"]
* StringUtils.splitPreserveAllTokens(":cd:ef:", ":") = ["", cd", "ef", ""]
* </pre>
*
* @param str the String to parse, may be {@code null}
* @param separatorChars the characters used as the delimiters,
* {@code null} splits on whitespace
* @return an array of parsed Strings, {@code null} if null String input
*/
public static String[] splitPreserveAllTokens(String str, String separatorChars) {
return splitWorker(str, separatorChars, -1, true);
}
/**
* <p>Splits the provided text into an array with a maximum length,
* separators specified, preserving all tokens, including empty tokens
* created by adjacent separators.</p>
*
* <p>The separator is not included in the returned String array.
* Adjacent separators are treated as separators for empty tokens.
* Adjacent separators are treated as one separator.</p>
*
* <p>A {@code null} input String returns {@code null}.
* A {@code null} separatorChars splits on whitespace.</p>
*
* <p>If more than {@code max} delimited substrings are found, the last
* returned string includes all characters after the first {@code max - 1}
* returned strings (including separator characters).</p>
*
* <pre>
* StringUtils.splitPreserveAllTokens(null, *, *) = null
* StringUtils.splitPreserveAllTokens("", *, *) = []
* StringUtils.splitPreserveAllTokens("ab de fg", null, 0) = ["ab", "cd", "ef"]
* StringUtils.splitPreserveAllTokens("ab de fg", null, 0) = ["ab", "cd", "ef"]
* StringUtils.splitPreserveAllTokens("ab:cd:ef", ":", 0) = ["ab", "cd", "ef"]
* StringUtils.splitPreserveAllTokens("ab:cd:ef", ":", 2) = ["ab", "cd:ef"]
* StringUtils.splitPreserveAllTokens("ab de fg", null, 2) = ["ab", " de fg"]
* StringUtils.splitPreserveAllTokens("ab de fg", null, 3) = ["ab", "", " de fg"]
* StringUtils.splitPreserveAllTokens("ab de fg", null, 4) = ["ab", "", "", "de fg"]
* </pre>
*
* @param str the String to parse, may be {@code null}
* @param separatorChars the characters used as the delimiters,
* {@code null} splits on whitespace
* @param max the maximum number of elements to include in the
* array. A zero or negative value implies no limit
* @return an array of parsed Strings, {@code null} if null String input
*/
public static String[] splitPreserveAllTokens(String str, String separatorChars, int max) {
return splitWorker(str, separatorChars, max, true);
}
/**
* Performs the logic for the {@code split} and
* {@code splitPreserveAllTokens} methods that return a maximum array
* length.
*
* @param str the String to parse, may be {@code null}
* @param separatorChars the separate character
* @param max the maximum number of elements to include in the
* array. A zero or negative value implies no limit.
* @param preserveAllTokens if {@code true}, adjacent separators are
* treated as empty token separators; if {@code false}, adjacent
* separators are treated as one separator.
* @return an array of parsed Strings, {@code null} if null String input
*/
private static String[] splitWorker(String str, String separatorChars, int max, boolean preserveAllTokens) {
// Performance tuned for 2.0 (JDK1.4)
// Direct code is quicker than StringTokenizer.
// Also, StringTokenizer uses isSpace() not isWhitespace()
if (str == null) {
return null;
}
int len = str.length();
if (len == 0) {
return ArrayUtils.EMPTY_STRING_ARRAY;
}
List<String> list = new ArrayList<String>();
int sizePlus1 = 1;
int i = 0, start = 0;
boolean match = false;
boolean lastMatch = false;
if (separatorChars == null) {
// Null separator means use whitespace
while (i < len) {
if (Character.isWhitespace(str.charAt(i))) {
if (match || preserveAllTokens) {
lastMatch = true;
if (sizePlus1++ == max) {
i = len;
lastMatch = false;
}
list.add(str.substring(start, i));
match = false;
}
start = ++i;
continue;
}
lastMatch = false;
match = true;
i++;
}
} else if (separatorChars.length() == 1) {
// Optimise 1 character case
char sep = separatorChars.charAt(0);
while (i < len) {
if (str.charAt(i) == sep) {
if (match || preserveAllTokens) {
lastMatch = true;
if (sizePlus1++ == max) {
i = len;
lastMatch = false;
}
list.add(str.substring(start, i));
match = false;
}
start = ++i;
continue;
}
lastMatch = false;
match = true;
i++;
}
} else {
// standard case
while (i < len) {
if (separatorChars.indexOf(str.charAt(i)) >= 0) {
if (match || preserveAllTokens) {
lastMatch = true;
if (sizePlus1++ == max) {
i = len;
lastMatch = false;
}
list.add(str.substring(start, i));
match = false;
}
start = ++i;
continue;
}
lastMatch = false;
match = true;
i++;
}
}
if (match || preserveAllTokens && lastMatch) {
list.add(str.substring(start, i));
}
return list.toArray(new String[list.size()]);
}
/**
* <p>Splits a String by Character type as returned by
* {@code java.lang.Character.getType(char)}. Groups of contiguous
* characters of the same type are returned as complete tokens.
* <pre>
* StringUtils.splitByCharacterType(null) = null
* StringUtils.splitByCharacterType("") = []
* StringUtils.splitByCharacterType("ab de fg") = ["ab", " ", "de", " ", "fg"]
* StringUtils.splitByCharacterType("ab de fg") = ["ab", " ", "de", " ", "fg"]
* StringUtils.splitByCharacterType("ab:cd:ef") = ["ab", ":", "cd", ":", "ef"]
* StringUtils.splitByCharacterType("number5") = ["number", "5"]
* StringUtils.splitByCharacterType("fooBar") = ["foo", "B", "ar"]
* StringUtils.splitByCharacterType("foo200Bar") = ["foo", "200", "B", "ar"]
* StringUtils.splitByCharacterType("ASFRules") = ["ASFR", "ules"]
* </pre>
* @param str the String to split, may be {@code null}
* @return an array of parsed Strings, {@code null} if null String input
*/
public static String[] splitByCharacterType(String str) {
return splitByCharacterType(str, false);
}
/**
* <p>Splits a String by Character type as returned by
* {@code java.lang.Character.getType(char)}. Groups of contiguous
* characters of the same type are returned as complete tokens, with the
* following exception: the character of type
* {@code Character.UPPERCASE_LETTER}, if any, immediately
* preceding a token of type {@code Character.LOWERCASE_LETTER}
* will belong to the following token rather than to the preceding, if any,
* {@code Character.UPPERCASE_LETTER} token.
* <pre>
* StringUtils.splitByCharacterTypeCamelCase(null) = null
* StringUtils.splitByCharacterTypeCamelCase("") = []
* StringUtils.splitByCharacterTypeCamelCase("ab de fg") = ["ab", " ", "de", " ", "fg"]
* StringUtils.splitByCharacterTypeCamelCase("ab de fg") = ["ab", " ", "de", " ", "fg"]
* StringUtils.splitByCharacterTypeCamelCase("ab:cd:ef") = ["ab", ":", "cd", ":", "ef"]
* StringUtils.splitByCharacterTypeCamelCase("number5") = ["number", "5"]
* StringUtils.splitByCharacterTypeCamelCase("fooBar") = ["foo", "Bar"]
* StringUtils.splitByCharacterTypeCamelCase("foo200Bar") = ["foo", "200", "Bar"]
* StringUtils.splitByCharacterTypeCamelCase("ASFRules") = ["ASF", "Rules"]
* </pre>
* @param str the String to split, may be {@code null}
* @return an array of parsed Strings, {@code null} if null String input
*/
public static String[] splitByCharacterTypeCamelCase(String str) {
return splitByCharacterType(str, true);
}
/**
* <p>Splits a String by Character type as returned by
* {@code java.lang.Character.getType(char)}. Groups of contiguous
* characters of the same type are returned as complete tokens, with the
* following exception: if {@code camelCase} is {@code true},
* the character of type {@code Character.UPPERCASE_LETTER}, if any,
* immediately preceding a token of type {@code Character.LOWERCASE_LETTER}
* will belong to the following token rather than to the preceding, if any,
* {@code Character.UPPERCASE_LETTER} token.
* @param str the String to split, may be {@code null}
* @param camelCase whether to use so-called "camel-case" for letter types
* @return an array of parsed Strings, {@code null} if null String input
*/
private static String[] splitByCharacterType(String str, boolean camelCase) {
if (str == null) {
return null;
}
if (str.length() == 0) {
return ArrayUtils.EMPTY_STRING_ARRAY;
}
char[] c = str.toCharArray();
List<String> list = new ArrayList<String>();
int tokenStart = 0;
int currentType = Character.getType(c[tokenStart]);
for (int pos = tokenStart + 1; pos < c.length; pos++) {
int type = Character.getType(c[pos]);
if (type == currentType) {
continue;
}
if (camelCase && type == Character.LOWERCASE_LETTER && currentType == Character.UPPERCASE_LETTER) {
int newTokenStart = pos - 1;
if (newTokenStart != tokenStart) {
list.add(new String(c, tokenStart, newTokenStart - tokenStart));
tokenStart = newTokenStart;
}
} else {
list.add(new String(c, tokenStart, pos - tokenStart));
tokenStart = pos;
}
currentType = type;
}
list.add(new String(c, tokenStart, c.length - tokenStart));
return list.toArray(new String[list.size()]);
}
// Joining
//-----------------------------------------------------------------------
/**
* <p>Joins the elements of the provided array into a single String
* containing the provided list of elements.</p>
*
* <p>No delimiter is added before or after the list.
* Null objects or empty strings within the array are represented by
* empty strings.</p>
*
* <pre>
* StringUtils.join(null, *) = null
* StringUtils.join([], *) = ""
* StringUtils.join([null], *) = ""
* StringUtils.join(["a", "b", "c"], ';') = "a;b;c"
* StringUtils.join(["a", "b", "c"], null) = "abc"
* StringUtils.join([null, "", "a"], ';') = ";;a"
* </pre>
*
* @param array the array of values to join together, may be null
* @param separator the separator character to use
* @return the joined String, {@code null} if null array input
*/
public static String join(Object[] array, char separator) {
if (array == null) {
return null;
}
return join(array, separator, 0, array.length);
}
/**
* <p>Joins the elements of the provided array into a single String
* containing the provided list of elements.</p>
*
* <p>No delimiter is added before or after the list.
* Null objects or empty strings within the array are represented by
* empty strings.</p>
*
* <pre>
* StringUtils.join(null, *) = null
* StringUtils.join([], *) = ""
* StringUtils.join([null], *) = ""
* StringUtils.join(["a", "b", "c"], ';') = "a;b;c"
* StringUtils.join(["a", "b", "c"], null) = "abc"
* StringUtils.join([null, "", "a"], ';') = ";;a"
* </pre>
*
* @param array the array of values to join together, may be null
* @param separator the separator character to use
* @param startIndex the first index to start joining from. It is
* an error to pass in an end index past the end of the array
* @param endIndex the index to stop joining from (exclusive). It is
* an error to pass in an end index past the end of the array
* @return the joined String, {@code null} if null array input
*/
public static String join(Object[] array, char separator, int startIndex, int endIndex) {
if (array == null) {
return null;
}
int noOfItems = endIndex - startIndex;
if (noOfItems <= 0) {
return EMPTY;
}
StringBuilder buf = new StringBuilder(noOfItems * 16);
for (int i = startIndex; i < endIndex; i++) {
if (i > startIndex) {
buf.append(separator);
}
if (array[i] != null) {
buf.append(array[i]);
}
}
return buf.toString();
}
/**
* <p>Joins the elements of the provided array into a single String
* containing the provided list of elements.</p>
*
* <p>No delimiter is added before or after the list.
* A {@code null} separator is the same as an empty String ("").
* Null objects or empty strings within the array are represented by
* empty strings.</p>
*
* <pre>
* StringUtils.join(null, *) = null
* StringUtils.join([], *) = ""
* StringUtils.join([null], *) = ""
* StringUtils.join(["a", "b", "c"], "--") = "a--b--c"
* StringUtils.join(["a", "b", "c"], null) = "abc"
* StringUtils.join(["a", "b", "c"], "") = "abc"
* StringUtils.join([null, "", "a"], ',') = ",,a"
* </pre>
*
* @param array the array of values to join together, may be null
* @param separator the separator character to use, null treated as ""
* @return the joined String, {@code null} if null array input
*/
public static String join(Object[] array, String separator) {
if (array == null) {
return null;
}
return join(array, separator, 0, array.length);
}
/**
* <p>Joins the elements of the provided array into a single String
* containing the provided list of elements.</p>
*
* <p>No delimiter is added before or after the list.
* A {@code null} separator is the same as an empty String ("").
* Null objects or empty strings within the array are represented by
* empty strings.</p>
*
* <pre>
* StringUtils.join(null, *) = null
* StringUtils.join([], *) = ""
* StringUtils.join([null], *) = ""
* StringUtils.join(["a", "b", "c"], "--") = "a--b--c"
* StringUtils.join(["a", "b", "c"], null) = "abc"
* StringUtils.join(["a", "b", "c"], "") = "abc"
* StringUtils.join([null, "", "a"], ',') = ",,a"
* </pre>
*
* @param array the array of values to join together, may be null
* @param separator the separator character to use, null treated as ""
* @param startIndex the first index to start joining from. It is
* an error to pass in an end index past the end of the array
* @param endIndex the index to stop joining from (exclusive). It is
* an error to pass in an end index past the end of the array
* @return the joined String, {@code null} if null array input
*/
public static String join(Object[] array, String separator, int startIndex, int endIndex) {
if (array == null) {
return null;
}
if (separator == null) {
separator = EMPTY;
}
// endIndex - startIndex > 0: Len = NofStrings *(len(firstString) + len(separator))
// (Assuming that all Strings are roughly equally long)
int noOfItems = endIndex - startIndex;
if (noOfItems <= 0) {
return EMPTY;
}
StringBuilder buf = new StringBuilder(noOfItems * 16);
for (int i = startIndex; i < endIndex; i++) {
if (i > startIndex) {
buf.append(separator);
}
if (array[i] != null) {
buf.append(array[i]);
}
}
return buf.toString();
}
/**
* <p>Joins the elements of the provided {@code Iterator} into
* a single String containing the provided elements.</p>
*
* <p>No delimiter is added before or after the list. Null objects or empty
* strings within the iteration are represented by empty strings.</p>
*
* <p>See the examples here: {@link #join(Object[],char)}. </p>
*
* @param iterator the {@code Iterator} of values to join together, may be null
* @param separator the separator character to use
* @return the joined String, {@code null} if null iterator input
*/
public static String join(Iterator<?> iterator, char separator) {
// handle null, zero and one elements before building a buffer
if (iterator == null) {
return null;
}
if (!iterator.hasNext()) {
return EMPTY;
}
Object first = iterator.next();
if (!iterator.hasNext()) {
return ObjectUtils.toString(first);
}
// two or more elements
StringBuilder buf = new StringBuilder(64); // Java default is 16, probably too small
if (first != null) {
buf.append(first);
}
while (iterator.hasNext()) {
buf.append(separator);
Object obj = iterator.next();
if (obj != null) {
buf.append(obj);
}
}
return buf.toString();
}
/**
* <p>Joins the elements of the provided {@code Iterator} into
* a single String containing the provided elements.</p>
*
* <p>No delimiter is added before or after the list.
* A {@code null} separator is the same as an empty String ("").</p>
*
* <p>See the examples here: {@link #join(Object[],String)}. </p>
*
* @param iterator the {@code Iterator} of values to join together, may be null
* @param separator the separator character to use, null treated as ""
* @return the joined String, {@code null} if null iterator input
*/
public static String join(Iterator<?> iterator, String separator) {
// handle null, zero and one elements before building a buffer
if (iterator == null) {
return null;
}
if (!iterator.hasNext()) {
return EMPTY;
}
Object first = iterator.next();
if (!iterator.hasNext()) {
return ObjectUtils.toString(first);
}
// two or more elements
StringBuilder buf = new StringBuilder(64); // Java default is 16, probably too small
if (first != null) {
buf.append(first);
}
while (iterator.hasNext()) {
if (separator != null) {
buf.append(separator);
}
Object obj = iterator.next();
if (obj != null) {
buf.append(obj);
}
}
return buf.toString();
}
/**
* <p>Joins the elements of the provided {@code Iterable} into
* a single String containing the provided elements.</p>
*
* <p>No delimiter is added before or after the list. Null objects or empty
* strings within the iteration are represented by empty strings.</p>
*
* <p>See the examples here: {@link #join(Object[],char)}. </p>
*
* @param iterable the {@code Iterable} providing the values to join together, may be null
* @param separator the separator character to use
* @return the joined String, {@code null} if null iterator input
*/
public static String join(Iterable<?> iterable, char separator) {
if (iterable == null) {
return null;
}
return join(iterable.iterator(), separator);
}
/**
* <p>Joins the elements of the provided {@code Iterable} into
* a single String containing the provided elements.</p>
*
* <p>No delimiter is added before or after the list.
* A {@code null} separator is the same as an empty String ("").</p>
*
* <p>See the examples here: {@link #join(Object[],String)}. </p>
*
* @param iterable the {@code Iterable} providing the values to join together, may be null
* @param separator the separator character to use, null treated as ""
* @return the joined String, {@code null} if null iterator input
*/
public static String join(Iterable<?> iterable, String separator) {
if (iterable == null) {
return null;
}
return join(iterable.iterator(), separator);
}
// Delete
//-----------------------------------------------------------------------
/**
* <p>Deletes all whitespaces from a String as defined by
* {@link Character#isWhitespace(char)}.</p>
*
* <pre>
* StringUtils.deleteWhitespace(null) = null
* StringUtils.deleteWhitespace("") = ""
* StringUtils.deleteWhitespace("abc") = "abc"
* StringUtils.deleteWhitespace(" ab c ") = "abc"
* </pre>
*
* @param str the String to delete whitespace from, may be null
* @return the String without whitespaces, {@code null} if null String input
*/
public static String deleteWhitespace(String str) {
if (isEmpty(str)) {
return str;
}
int sz = str.length();
char[] chs = new char[sz];
int count = 0;
for (int i = 0; i < sz; i++) {
if (!Character.isWhitespace(str.charAt(i))) {
chs[count++] = str.charAt(i);
}
}
if (count == sz) {
return str;
}
return new String(chs, 0, count);
}
// Remove
//-----------------------------------------------------------------------
/**
* <p>Removes all occurrences of a substring from within the source string.</p>
*
* <p>A {@code null} source string will return {@code null}.
* An empty ("") source string will return the empty string.
* A {@code null} remove string will return the source string.
* An empty ("") remove string will return the source string.</p>
*
* <pre>
* StringUtils.remove(null, *) = null
* StringUtils.remove("", *) = ""
* StringUtils.remove(*, null) = *
* StringUtils.remove(*, "") = *
* StringUtils.remove("queued", "ue") = "qd"
* StringUtils.remove("queued", "zz") = "queued"
* </pre>
*
* @param str the source String to search, may be null
* @param remove the String to search for and remove, may be null
* @return the substring with the string removed if found,
* {@code null} if null String input
*/
public static String remove(String str, String remove) {
if (isEmpty(str) || isEmpty(remove)) {
return str;
}
return replace(str, remove, EMPTY, -1);
}
/**
* <p>Removes all occurrences of a character from within the source string.</p>
*
* <p>A {@code null} source string will return {@code null}.
* An empty ("") source string will return the empty string.</p>
*
* <pre>
* StringUtils.remove(null, *) = null
* StringUtils.remove("", *) = ""
* StringUtils.remove("queued", 'u') = "qeed"
* StringUtils.remove("queued", 'z') = "queued"
* </pre>
*
* @param str the source String to search, may be null
* @param remove the char to search for and remove, may be null
* @return the substring with the char removed if found,
* {@code null} if null String input
*/
public static String remove(String str, char remove) {
if (isEmpty(str) || str.indexOf(remove) == INDEX_NOT_FOUND) {
return str;
}
char[] chars = str.toCharArray();
int pos = 0;
for (int i = 0; i < chars.length; i++) {
if (chars[i] != remove) {
chars[pos++] = chars[i];
}
}
return new String(chars, 0, pos);
}
// Replacing
//-----------------------------------------------------------------------
/**
* <p>Replaces a String with another String inside a larger String, once.</p>
*
* <p>A {@code null} reference passed to this method is a no-op.</p>
*
* <pre>
* StringUtils.replaceOnce(null, *, *) = null
* StringUtils.replaceOnce("", *, *) = ""
* StringUtils.replaceOnce("any", null, *) = "any"
* StringUtils.replaceOnce("any", *, null) = "any"
* StringUtils.replaceOnce("any", "", *) = "any"
* StringUtils.replaceOnce("aba", "a", null) = "aba"
* StringUtils.replaceOnce("aba", "a", "") = "ba"
* StringUtils.replaceOnce("aba", "a", "z") = "zba"
* </pre>
*
* @see #replace(String text, String searchString, String replacement, int max)
* @param text text to search and replace in, may be null
* @param searchString the String to search for, may be null
* @param replacement the String to replace with, may be null
* @return the text with any replacements processed,
* {@code null} if null String input
*/
public static String replaceOnce(String text, String searchString, String replacement) {
return replace(text, searchString, replacement, 1);
}
/**
* <p>Replaces all occurrences of a String within another String.</p>
*
* <p>A {@code null} reference passed to this method is a no-op.</p>
*
* <pre>
* StringUtils.replace(null, *, *) = null
* StringUtils.replace("", *, *) = ""
* StringUtils.replace("any", null, *) = "any"
* StringUtils.replace("any", *, null) = "any"
* StringUtils.replace("any", "", *) = "any"
* StringUtils.replace("aba", "a", null) = "aba"
* StringUtils.replace("aba", "a", "") = "b"
* StringUtils.replace("aba", "a", "z") = "zbz"
* </pre>
*
* @see #replace(String text, String searchString, String replacement, int max)
* @param text text to search and replace in, may be null
* @param searchString the String to search for, may be null
* @param replacement the String to replace it with, may be null
* @return the text with any replacements processed,
* {@code null} if null String input
*/
public static String replace(String text, String searchString, String replacement) {
return replace(text, searchString, replacement, -1);
}
/**
* <p>Replaces a String with another String inside a larger String,
* for the first {@code max} values of the search String.</p>
*
* <p>A {@code null} reference passed to this method is a no-op.</p>
*
* <pre>
* StringUtils.replace(null, *, *, *) = null
* StringUtils.replace("", *, *, *) = ""
* StringUtils.replace("any", null, *, *) = "any"
* StringUtils.replace("any", *, null, *) = "any"
* StringUtils.replace("any", "", *, *) = "any"
* StringUtils.replace("any", *, *, 0) = "any"
* StringUtils.replace("abaa", "a", null, -1) = "abaa"
* StringUtils.replace("abaa", "a", "", -1) = "b"
* StringUtils.replace("abaa", "a", "z", 0) = "abaa"
* StringUtils.replace("abaa", "a", "z", 1) = "zbaa"
* StringUtils.replace("abaa", "a", "z", 2) = "zbza"
* StringUtils.replace("abaa", "a", "z", -1) = "zbzz"
* </pre>
*
* @param text text to search and replace in, may be null
* @param searchString the String to search for, may be null
* @param replacement the String to replace it with, may be null
* @param max maximum number of values to replace, or {@code -1} if no maximum
* @return the text with any replacements processed,
* {@code null} if null String input
*/
public static String replace(String text, String searchString, String replacement, int max) {
if (isEmpty(text) || isEmpty(searchString) || replacement == null || max == 0) {
return text;
}
int start = 0;
int end = text.indexOf(searchString, start);
if (end == INDEX_NOT_FOUND) {
return text;
}
int replLength = searchString.length();
int increase = replacement.length() - replLength;
increase = increase < 0 ? 0 : increase;
increase *= max < 0 ? 16 : max > 64 ? 64 : max;
StringBuilder buf = new StringBuilder(text.length() + increase);
while (end != INDEX_NOT_FOUND) {
buf.append(text.substring(start, end)).append(replacement);
start = end + replLength;
if (--max == 0) {
break;
}
end = text.indexOf(searchString, start);
}
buf.append(text.substring(start));
return buf.toString();
}
// Replace, character based
//-----------------------------------------------------------------------
/**
* <p>Replaces all occurrences of a character in a String with another.
* This is a null-safe version of {@link String#replace(char, char)}.</p>
*
* <p>A {@code null} string input returns {@code null}.
* An empty ("") string input returns an empty string.</p>
*
* <pre>
* StringUtils.replaceChars(null, *, *) = null
* StringUtils.replaceChars("", *, *) = ""
* StringUtils.replaceChars("abcba", 'b', 'y') = "aycya"
* StringUtils.replaceChars("abcba", 'z', 'y') = "abcba"
* </pre>
*
* @param str String to replace characters in, may be null
* @param searchChar the character to search for, may be null
* @param replaceChar the character to replace, may be null
* @return modified String, {@code null} if null string input
*/
public static String replaceChars(String str, char searchChar, char replaceChar) {
if (str == null) {
return null;
}
return str.replace(searchChar, replaceChar);
}
/**
* <p>Replaces multiple characters in a String in one go.
* This method can also be used to delete characters.</p>
*
* <p>For example:<br />
* <code>replaceChars("hello", "ho", "jy") = jelly</code>.</p>
*
* <p>A {@code null} string input returns {@code null}.
* An empty ("") string input returns an empty string.
* A null or empty set of search characters returns the input string.</p>
*
* <p>The length of the search characters should normally equal the length
* of the replace characters.
* If the search characters is longer, then the extra search characters
* are deleted.
* If the search characters is shorter, then the extra replace characters
* are ignored.</p>
*
* <pre>
* StringUtils.replaceChars(null, *, *) = null
* StringUtils.replaceChars("", *, *) = ""
* StringUtils.replaceChars("abc", null, *) = "abc"
* StringUtils.replaceChars("abc", "", *) = "abc"
* StringUtils.replaceChars("abc", "b", null) = "ac"
* StringUtils.replaceChars("abc", "b", "") = "ac"
* StringUtils.replaceChars("abcba", "bc", "yz") = "ayzya"
* StringUtils.replaceChars("abcba", "bc", "y") = "ayya"
* StringUtils.replaceChars("abcba", "bc", "yzx") = "ayzya"
* </pre>
*
* @param str String to replace characters in, may be null
* @param searchChars a set of characters to search for, may be null
* @param replaceChars a set of characters to replace, may be null
* @return modified String, {@code null} if null string input
*/
public static String replaceChars(String str, String searchChars, String replaceChars) {
if (isEmpty(str) || isEmpty(searchChars)) {
return str;
}
if (replaceChars == null) {
replaceChars = EMPTY;
}
boolean modified = false;
int replaceCharsLength = replaceChars.length();
int strLength = str.length();
StringBuilder buf = new StringBuilder(strLength);
for (int i = 0; i < strLength; i++) {
char ch = str.charAt(i);
int index = searchChars.indexOf(ch);
if (index >= 0) {
modified = true;
if (index < replaceCharsLength) {
buf.append(replaceChars.charAt(index));
}
} else {
buf.append(ch);
}
}
if (modified) {
return buf.toString();
}
return str;
}
// Chomping
//-----------------------------------------------------------------------
/**
* <p>Removes one newline from end of a String if it's there,
* otherwise leave it alone. A newline is "{@code \n}",
* "{@code \r}", or "{@code \r\n}".</p>
*
* <p>NOTE: This method changed in 2.0.
* It now more closely matches Perl chomp.</p>
*
* <pre>
* StringUtils.chomp(null) = null
* StringUtils.chomp("") = ""
* StringUtils.chomp("abc \r") = "abc "
* StringUtils.chomp("abc\n") = "abc"
* StringUtils.chomp("abc\r\n") = "abc"
* StringUtils.chomp("abc\r\n\r\n") = "abc\r\n"
* StringUtils.chomp("abc\n\r") = "abc\n"
* StringUtils.chomp("abc\n\rabc") = "abc\n\rabc"
* StringUtils.chomp("\r") = ""
* StringUtils.chomp("\n") = ""
* StringUtils.chomp("\r\n") = ""
* </pre>
*
* @param str the String to chomp a newline from, may be null
* @return String without newline, {@code null} if null String input
*/
public static String chomp(String str) {
if (isEmpty(str)) {
return str;
}
if (str.length() == 1) {
char ch = str.charAt(0);
if (ch == CharUtils.CR || ch == CharUtils.LF) {
return EMPTY;
}
return str;
}
int lastIdx = str.length() - 1;
char last = str.charAt(lastIdx);
if (last == CharUtils.LF) {
if (str.charAt(lastIdx - 1) == CharUtils.CR) {
lastIdx--;
}
} else if (last != CharUtils.CR) {
lastIdx++;
}
return str.substring(0, lastIdx);
}
// Chopping
//-----------------------------------------------------------------------
/**
* <p>Remove the last character from a String.</p>
*
* <p>If the String ends in {@code \r\n}, then remove both
* of them.</p>
*
* <pre>
* StringUtils.chop(null) = null
* StringUtils.chop("") = ""
* StringUtils.chop("abc \r") = "abc "
* StringUtils.chop("abc\n") = "abc"
* StringUtils.chop("abc\r\n") = "abc"
* StringUtils.chop("abc") = "ab"
* StringUtils.chop("abc\nabc") = "abc\nab"
* StringUtils.chop("a") = ""
* StringUtils.chop("\r") = ""
* StringUtils.chop("\n") = ""
* StringUtils.chop("\r\n") = ""
* </pre>
*
* @param str the String to chop last character from, may be null
* @return String without last character, {@code null} if null String input
*/
public static String chop(String str) {
if (str == null) {
return null;
}
int strLen = str.length();
if (strLen < 2) {
return EMPTY;
}
int lastIdx = strLen - 1;
String ret = str.substring(0, lastIdx);
char last = str.charAt(lastIdx);
if (last == CharUtils.LF && ret.charAt(lastIdx - 1) == CharUtils.CR) {
return ret.substring(0, lastIdx - 1);
}
return ret;
}
// Padding
//-----------------------------------------------------------------------
/**
* <p>Repeat a String {@code repeat} times to form a
* new String.</p>
*
* <pre>
* StringUtils.repeat(null, 2) = null
* StringUtils.repeat("", 0) = ""
* StringUtils.repeat("", 2) = ""
* StringUtils.repeat("a", 3) = "aaa"
* StringUtils.repeat("ab", 2) = "abab"
* StringUtils.repeat("a", -2) = ""
* </pre>
*
* @param str the String to repeat, may be null
* @param repeat number of times to repeat str, negative treated as zero
* @return a new String consisting of the original String repeated,
* {@code null} if null String input
*/
public static String repeat(String str, int repeat) {
// Performance tuned for 2.0 (JDK1.4)
if (str == null) {
return null;
}
if (repeat <= 0) {
return EMPTY;
}
int inputLength = str.length();
if (repeat == 1 || inputLength == 0) {
return str;
}
if (inputLength == 1 && repeat <= PAD_LIMIT) {
return repeat(str.charAt(0), repeat);
}
int outputLength = inputLength * repeat;
switch (inputLength) {
case 1 :
return repeat(str.charAt(0), repeat);
case 2 :
char ch0 = str.charAt(0);
char ch1 = str.charAt(1);
char[] output2 = new char[outputLength];
for (int i = repeat * 2 - 2; i >= 0; i--, i--) {
output2[i] = ch0;
output2[i + 1] = ch1;
}
return new String(output2);
default :
StringBuilder buf = new StringBuilder(outputLength);
for (int i = 0; i < repeat; i++) {
buf.append(str);
}
return buf.toString();
}
}
/**
* <p>Returns padding using the specified delimiter repeated
* to a given length.</p>
*
* <pre>
* StringUtils.repeat(0, 'e') = ""
* StringUtils.repeat(3, 'e') = "eee"
* StringUtils.repeat(-2, 'e') = ""
* </pre>
*
* <p>Note: this method doesn't not support padding with
* <a href="http://www.unicode.org/glossary/#supplementary_character">Unicode Supplementary Characters</a>
* as they require a pair of {@code char}s to be represented.
* If you are needing to support full I18N of your applications
* consider using {@link #repeat(String, int)} instead.
* </p>
*
* @param ch character to repeat
* @param repeat number of times to repeat char, negative treated as zero
* @return String with repeated character
* @see #repeat(String, int)
*/
public static String repeat(char ch, int repeat) {
char[] buf = new char[repeat];
for (int i = repeat - 1; i >= 0; i--) {
buf[i] = ch;
}
return new String(buf);
}
/**
* <p>Right pad a String with spaces (' ').</p>
*
* <p>The String is padded to the size of {@code size}.</p>
*
* <pre>
* StringUtils.rightPad(null, *) = null
* StringUtils.rightPad("", 3) = " "
* StringUtils.rightPad("bat", 3) = "bat"
* StringUtils.rightPad("bat", 5) = "bat "
* StringUtils.rightPad("bat", 1) = "bat"
* StringUtils.rightPad("bat", -1) = "bat"
* </pre>
*
* @param str the String to pad out, may be null
* @param size the size to pad to
* @return right padded String or original String if no padding is necessary,
* {@code null} if null String input
*/
public static String rightPad(String str, int size) {
return rightPad(str, size, ' ');
}
/**
* <p>Right pad a String with a specified character.</p>
*
* <p>The String is padded to the size of {@code size}.</p>
*
* <pre>
* StringUtils.rightPad(null, *, *) = null
* StringUtils.rightPad("", 3, 'z') = "zzz"
* StringUtils.rightPad("bat", 3, 'z') = "bat"
* StringUtils.rightPad("bat", 5, 'z') = "batzz"
* StringUtils.rightPad("bat", 1, 'z') = "bat"
* StringUtils.rightPad("bat", -1, 'z') = "bat"
* </pre>
*
* @param str the String to pad out, may be null
* @param size the size to pad to
* @param padChar the character to pad with
* @return right padded String or original String if no padding is necessary,
* {@code null} if null String input
*/
public static String rightPad(String str, int size, char padChar) {
if (str == null) {
return null;
}
int pads = size - str.length();
if (pads <= 0) {
return str; // returns original String when possible
}
if (pads > PAD_LIMIT) {
return rightPad(str, size, String.valueOf(padChar));
}
return str.concat(repeat(padChar, pads));
}
/**
* <p>Right pad a String with a specified String.</p>
*
* <p>The String is padded to the size of {@code size}.</p>
*
* <pre>
* StringUtils.rightPad(null, *, *) = null
* StringUtils.rightPad("", 3, "z") = "zzz"
* StringUtils.rightPad("bat", 3, "yz") = "bat"
* StringUtils.rightPad("bat", 5, "yz") = "batyz"
* StringUtils.rightPad("bat", 8, "yz") = "batyzyzy"
* StringUtils.rightPad("bat", 1, "yz") = "bat"
* StringUtils.rightPad("bat", -1, "yz") = "bat"
* StringUtils.rightPad("bat", 5, null) = "bat "
* StringUtils.rightPad("bat", 5, "") = "bat "
* </pre>
*
* @param str the String to pad out, may be null
* @param size the size to pad to
* @param padStr the String to pad with, null or empty treated as single space
* @return right padded String or original String if no padding is necessary,
* {@code null} if null String input
*/
public static String rightPad(String str, int size, String padStr) {
if (str == null) {
return null;
}
if (isEmpty(padStr)) {
padStr = " ";
}
int padLen = padStr.length();
int strLen = str.length();
int pads = size - strLen;
if (pads <= 0) {
return str; // returns original String when possible
}
if (padLen == 1 && pads <= PAD_LIMIT) {
return rightPad(str, size, padStr.charAt(0));
}
if (pads == padLen) {
return str.concat(padStr);
} else if (pads < padLen) {
return str.concat(padStr.substring(0, pads));
} else {
char[] padding = new char[pads];
char[] padChars = padStr.toCharArray();
for (int i = 0; i < pads; i++) {
padding[i] = padChars[i % padLen];
}
return str.concat(new String(padding));
}
}
/**
* <p>Left pad a String with spaces (' ').</p>
*
* <p>The String is padded to the size of {@code size}.</p>
*
* <pre>
* StringUtils.leftPad(null, *) = null
* StringUtils.leftPad("", 3) = " "
* StringUtils.leftPad("bat", 3) = "bat"
* StringUtils.leftPad("bat", 5) = " bat"
* StringUtils.leftPad("bat", 1) = "bat"
* StringUtils.leftPad("bat", -1) = "bat"
* </pre>
*
* @param str the String to pad out, may be null
* @param size the size to pad to
* @return left padded String or original String if no padding is necessary,
* {@code null} if null String input
*/
public static String leftPad(String str, int size) {
return leftPad(str, size, ' ');
}
/**
* <p>Left pad a String with a specified character.</p>
*
* <p>Pad to a size of {@code size}.</p>
*
* <pre>
* StringUtils.leftPad(null, *, *) = null
* StringUtils.leftPad("", 3, 'z') = "zzz"
* StringUtils.leftPad("bat", 3, 'z') = "bat"
* StringUtils.leftPad("bat", 5, 'z') = "zzbat"
* StringUtils.leftPad("bat", 1, 'z') = "bat"
* StringUtils.leftPad("bat", -1, 'z') = "bat"
* </pre>
*
* @param str the String to pad out, may be null
* @param size the size to pad to
* @param padChar the character to pad with
* @return left padded String or original String if no padding is necessary,
* {@code null} if null String input
*/
public static String leftPad(String str, int size, char padChar) {
if (str == null) {
return null;
}
int pads = size - str.length();
if (pads <= 0) {
return str; // returns original String when possible
}
if (pads > PAD_LIMIT) {
return leftPad(str, size, String.valueOf(padChar));
}
return repeat(padChar, pads).concat(str);
}
/**
* <p>Left pad a String with a specified String.</p>
*
* <p>Pad to a size of {@code size}.</p>
*
* <pre>
* StringUtils.leftPad(null, *, *) = null
* StringUtils.leftPad("", 3, "z") = "zzz"
* StringUtils.leftPad("bat", 3, "yz") = "bat"
* StringUtils.leftPad("bat", 5, "yz") = "yzbat"
* StringUtils.leftPad("bat", 8, "yz") = "yzyzybat"
* StringUtils.leftPad("bat", 1, "yz") = "bat"
* StringUtils.leftPad("bat", -1, "yz") = "bat"
* StringUtils.leftPad("bat", 5, null) = " bat"
* StringUtils.leftPad("bat", 5, "") = " bat"
* </pre>
*
* @param str the String to pad out, may be null
* @param size the size to pad to
* @param padStr the String to pad with, null or empty treated as single space
* @return left padded String or original String if no padding is necessary,
* {@code null} if null String input
*/
public static String leftPad(String str, int size, String padStr) {
if (str == null) {
return null;
}
if (isEmpty(padStr)) {
padStr = " ";
}
int padLen = padStr.length();
int strLen = str.length();
int pads = size - strLen;
if (pads <= 0) {
return str; // returns original String when possible
}
if (padLen == 1 && pads <= PAD_LIMIT) {
return leftPad(str, size, padStr.charAt(0));
}
if (pads == padLen) {
return padStr.concat(str);
} else if (pads < padLen) {
return padStr.substring(0, pads).concat(str);
} else {
char[] padding = new char[pads];
char[] padChars = padStr.toCharArray();
for (int i = 0; i < pads; i++) {
padding[i] = padChars[i % padLen];
}
return new String(padding).concat(str);
}
}
/**
* Gets a CharSequence length or {@code 0} if the CharSequence is
* {@code null}.
*
* @param cs
* a CharSequence or {@code null}
* @return CharSequence length or {@code 0} if the CharSequence is
* {@code null}.
*/
public static int length(CharSequence cs) {
return cs == null ? 0 : cs.length();
}
// Case conversion
//-----------------------------------------------------------------------
/**
* <p>Converts a String to upper case as per {@link String#toUpperCase()}.</p>
*
* <p>A {@code null} input String returns {@code null}.</p>
*
* <pre>
* StringUtils.upperCase(null) = null
* StringUtils.upperCase("") = ""
* StringUtils.upperCase("aBc") = "ABC"
* </pre>
*
* <p><strong>Note:</strong> As described in the documentation for {@link String#toUpperCase()},
* the result of this method is affected by the current locale.
* For platform-independent case transformations, the method {@link #lowerCase(String, Locale)}
* should be used with a specific locale (e.g. {@link Locale#ENGLISH}).</p>
*
* @param str the String to upper case, may be null
* @return the upper cased String, {@code null} if null String input
*/
public static String upperCase(String str) {
if (str == null) {
return null;
}
return str.toUpperCase();
}
/**
* <p>Converts a String to upper case as per {@link String#toUpperCase(Locale)}.</p>
*
* <p>A {@code null} input String returns {@code null}.</p>
*
* <pre>
* StringUtils.upperCase(null, Locale.ENGLISH) = null
* StringUtils.upperCase("", Locale.ENGLISH) = ""
* StringUtils.upperCase("aBc", Locale.ENGLISH) = "ABC"
* </pre>
*
* @param str the String to upper case, may be null
* @param locale the locale that defines the case transformation rules, must not be null
* @return the upper cased String, {@code null} if null String input
*/
public static String upperCase(String str, Locale locale) {
if (str == null) {
return null;
}
return str.toUpperCase(locale);
}
/**
* <p>Converts a String to lower case as per {@link String#toLowerCase()}.</p>
*
* <p>A {@code null} input String returns {@code null}.</p>
*
* <pre>
* StringUtils.lowerCase(null) = null
* StringUtils.lowerCase("") = ""
* StringUtils.lowerCase("aBc") = "abc"
* </pre>
*
* <p><strong>Note:</strong> As described in the documentation for {@link String#toLowerCase()},
* the result of this method is affected by the current locale.
* For platform-independent case transformations, the method {@link #lowerCase(String, Locale)}
* should be used with a specific locale (e.g. {@link Locale#ENGLISH}).</p>
*
* @param str the String to lower case, may be null
* @return the lower cased String, {@code null} if null String input
*/
public static String lowerCase(String str) {
if (str == null) {
return null;
}
return str.toLowerCase();
}
/**
* <p>Converts a String to lower case as per {@link String#toLowerCase(Locale)}.</p>
*
* <p>A {@code null} input String returns {@code null}.</p>
*
* <pre>
* StringUtils.lowerCase(null, Locale.ENGLISH) = null
* StringUtils.lowerCase("", Locale.ENGLISH) = ""
* StringUtils.lowerCase("aBc", Locale.ENGLISH) = "abc"
* </pre>
*
* @param str the String to lower case, may be null
* @param locale the locale that defines the case transformation rules, must not be null
* @return the lower cased String, {@code null} if null String input
*/
public static String lowerCase(String str, Locale locale) {
if (str == null) {
return null;
}
return str.toLowerCase(locale);
}
/**
* <p>Capitalizes a String changing the first letter to title case as
* per {@link Character#toTitleCase(char)}. No other letters are changed.</p>
*
* <pre>
* StringUtils.capitalize(null) = null
* StringUtils.capitalize("") = ""
* StringUtils.capitalize("cat") = "Cat"
* StringUtils.capitalize("cAt") = "CAt"
* </pre>
*
* @param str the String to capitalize, may be null
* @return the capitalized String, {@code null} if null String input
* @see #uncapitalize(String)
*/
public static String capitalize(String str) {
if (str == null || str.length() == 0) {
return str;
}
if (Character.isLowerCase(str.charAt(0))) {
char[] buffer = str.toCharArray();
buffer[0] = Character.toUpperCase(buffer[0]);
return new String(buffer);
}
return str;
}
/**
* <p>Uncapitalizes a String changing the first letter to title case as
* per {@link Character#toLowerCase(char)}. No other letters are changed.</p>
*
* <pre>
* StringUtils.uncapitalize(null) = null
* StringUtils.uncapitalize("") = ""
* StringUtils.uncapitalize("Cat") = "cat"
* StringUtils.uncapitalize("CAT") = "cAT"
* </pre>
*
* @param str the String to uncapitalize, may be null
* @return the uncapitalized String, {@code null} if null String input
* @see #capitalize(String)
*/
public static String uncapitalize(String str) {
if (str == null || str.length() == 0) {
return str;
}
if (Character.isUpperCase(str.charAt(0))) {
char[] buffer = str.toCharArray();
buffer[0] = Character.toLowerCase(buffer[0]);
return new String(buffer);
}
return str;
}
/**
* <p>Swaps the case of a String changing upper and title case to
* lower case, and lower case to upper case.</p>
*
* <ul>
* <li>Upper case character converts to Lower case</li>
* <li>Title case character converts to Lower case</li>
* <li>Lower case character converts to Upper case</li>
* </ul>
*
*
* <pre>
* StringUtils.swapCase(null) = null
* StringUtils.swapCase("") = ""
* StringUtils.swapCase("The dog has a BONE") = "tHE DOG HAS A bone"
* </pre>
*
* <p>NOTE: This method changed in Lang version 2.0.
* It no longer performs a word based algorithm.
* If you only use ASCII, you will notice no change.
* That functionality is available in org.apache.commons.lang3.text.WordUtils.</p>
*
* @param str the String to swap case, may be null
* @return the changed String, {@code null} if null String input
*/
public static String swapCase(String str) {
if (isEmpty(str)) {
return str;
}
char[] buffer = str.toCharArray();
for (int i = 0; i < buffer.length; i++) {
char ch = buffer[i];
if (Character.isUpperCase(ch) || Character.isTitleCase(ch)) {
buffer[i] = Character.toLowerCase(ch);
} else if (Character.isLowerCase(ch)) {
buffer[i] = Character.toUpperCase(ch);
}
}
return new String(buffer);
}
// Count matches
//-----------------------------------------------------------------------
/**
* <p>Counts how many times the substring appears in the larger string.</p>
*
* <p>A {@code null} or empty ("") String input returns {@code 0}.</p>
*
* <pre>
* StringUtils.countMatches(null, *) = 0
* StringUtils.countMatches("", *) = 0
* StringUtils.countMatches("abba", null) = 0
* StringUtils.countMatches("abba", "") = 0
* StringUtils.countMatches("abba", "a") = 2
* StringUtils.countMatches("abba", "ab") = 1
* StringUtils.countMatches("abba", "xxx") = 0
* </pre>
*
* @param str the CharSequence to check, may be null
* @param sub the substring to count, may be null
* @return the number of occurrences, 0 if either CharSequence is {@code null}
*/
public static int countMatches(CharSequence str, CharSequence sub) {
if (isEmpty(str) || isEmpty(sub)) {
return 0;
}
int count = 0;
int idx = 0;
while ((idx = CharSequenceUtils.indexOf(str, sub, idx)) != INDEX_NOT_FOUND) {
count++;
idx += sub.length();
}
return count;
}
// Character Tests
//-----------------------------------------------------------------------
/**
* <p>Checks if the CharSequence contains only Unicode letters.</p>
*
* <p>{@code null} will return {@code false}.
* An empty CharSequence (length()=0) will return {@code false}.</p>
*
* <pre>
* StringUtils.isAlpha(null) = false
* StringUtils.isAlpha("") = false
* StringUtils.isAlpha(" ") = false
* StringUtils.isAlpha("abc") = true
* StringUtils.isAlpha("ab2c") = false
* StringUtils.isAlpha("ab-c") = false
* </pre>
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if only contains letters, and is non-null
*/
public static boolean isAlpha(CharSequence cs) {
if (cs == null || cs.length() == 0) {
return false;
}
int sz = cs.length();
for (int i = 0; i < sz; i++) {
if (Character.isLetter(cs.charAt(i)) == false) {
return false;
}
}
return true;
}
/**
* <p>Checks if the CharSequence contains only Unicode letters and
* space (' ').</p>
*
* <p>{@code null} will return {@code false}
* An empty CharSequence (length()=0) will return {@code true}.</p>
*
* <pre>
* StringUtils.isAlphaSpace(null) = false
* StringUtils.isAlphaSpace("") = true
* StringUtils.isAlphaSpace(" ") = true
* StringUtils.isAlphaSpace("abc") = true
* StringUtils.isAlphaSpace("ab c") = true
* StringUtils.isAlphaSpace("ab2c") = false
* StringUtils.isAlphaSpace("ab-c") = false
* </pre>
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if only contains letters and space,
* and is non-null
*/
public static boolean isAlphaSpace(CharSequence cs) {
if (cs == null) {
return false;
}
int sz = cs.length();
for (int i = 0; i < sz; i++) {
if (Character.isLetter(cs.charAt(i)) == false && cs.charAt(i) != ' ') {
return false;
}
}
return true;
}
/**
* <p>Checks if the CharSequence contains only Unicode letters or digits.</p>
*
* <p>{@code null} will return {@code false}.
* An empty CharSequence (length()=0) will return {@code false}.</p>
*
* <pre>
* StringUtils.isAlphanumeric(null) = false
* StringUtils.isAlphanumeric("") = false
* StringUtils.isAlphanumeric(" ") = false
* StringUtils.isAlphanumeric("abc") = true
* StringUtils.isAlphanumeric("ab c") = false
* StringUtils.isAlphanumeric("ab2c") = true
* StringUtils.isAlphanumeric("ab-c") = false
* </pre>
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if only contains letters or digits,
* and is non-null
*/
public static boolean isAlphanumeric(CharSequence cs) {
if (cs == null || cs.length() == 0) {
return false;
}
int sz = cs.length();
for (int i = 0; i < sz; i++) {
if (Character.isLetterOrDigit(cs.charAt(i)) == false) {
return false;
}
}
return true;
}
/**
* <p>Checks if the CharSequence contains only Unicode letters, digits
* or space ({@code ' '}).</p>
*
* <p>{@code null} will return {@code false}.
* An empty CharSequence (length()=0) will return {@code true}.</p>
*
* <pre>
* StringUtils.isAlphanumericSpace(null) = false
* StringUtils.isAlphanumericSpace("") = true
* StringUtils.isAlphanumericSpace(" ") = true
* StringUtils.isAlphanumericSpace("abc") = true
* StringUtils.isAlphanumericSpace("ab c") = true
* StringUtils.isAlphanumericSpace("ab2c") = true
* StringUtils.isAlphanumericSpace("ab-c") = false
* </pre>
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if only contains letters, digits or space,
* and is non-null
*/
public static boolean isAlphanumericSpace(CharSequence cs) {
if (cs == null) {
return false;
}
int sz = cs.length();
for (int i = 0; i < sz; i++) {
if (Character.isLetterOrDigit(cs.charAt(i)) == false && cs.charAt(i) != ' ') {
return false;
}
}
return true;
}
/**
* <p>Checks if the CharSequence contains only ASCII printable characters.</p>
*
* <p>{@code null} will return {@code false}.
* An empty CharSequence (length()=0) will return {@code true}.</p>
*
* <pre>
* StringUtils.isAsciiPrintable(null) = false
* StringUtils.isAsciiPrintable("") = true
* StringUtils.isAsciiPrintable(" ") = true
* StringUtils.isAsciiPrintable("Ceki") = true
* StringUtils.isAsciiPrintable("ab2c") = true
* StringUtils.isAsciiPrintable("!ab-c~") = true
* StringUtils.isAsciiPrintable("\u0020") = true
* StringUtils.isAsciiPrintable("\u0021") = true
* StringUtils.isAsciiPrintable("\u007e") = true
* StringUtils.isAsciiPrintable("\u007f") = false
* StringUtils.isAsciiPrintable("Ceki G\u00fclc\u00fc") = false
* </pre>
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if every character is in the range
* 32 thru 126
*/
public static boolean isAsciiPrintable(CharSequence cs) {
if (cs == null) {
return false;
}
int sz = cs.length();
for (int i = 0; i < sz; i++) {
if (CharUtils.isAsciiPrintable(cs.charAt(i)) == false) {
return false;
}
}
return true;
}
/**
* <p>Checks if the CharSequence contains only Unicode digits.
* A decimal point is not a Unicode digit and returns false.</p>
*
* <p>{@code null} will return {@code false}.
* An empty CharSequence (length()=0) will return {@code false}.</p>
*
* <pre>
* StringUtils.isNumeric(null) = false
* StringUtils.isNumeric("") = false
* StringUtils.isNumeric(" ") = false
* StringUtils.isNumeric("123") = true
* StringUtils.isNumeric("12 3") = false
* StringUtils.isNumeric("ab2c") = false
* StringUtils.isNumeric("12-3") = false
* StringUtils.isNumeric("12.3") = false
* </pre>
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if only contains digits, and is non-null
*/
public static boolean isNumeric(CharSequence cs) {
if (cs == null || cs.length() == 0) {
return false;
}
int sz = cs.length();
for (int i = 0; i < sz; i++) {
if (Character.isDigit(cs.charAt(i)) == false) {
return false;
}
}
return true;
}
/**
* <p>Checks if the CharSequence contains only Unicode digits or space
* ({@code ' '}).
* A decimal point is not a Unicode digit and returns false.</p>
*
* <p>{@code null} will return {@code false}.
* An empty CharSequence (length()=0) will return {@code true}.</p>
*
* <pre>
* StringUtils.isNumericSpace(null) = false
* StringUtils.isNumericSpace("") = true
* StringUtils.isNumericSpace(" ") = true
* StringUtils.isNumericSpace("123") = true
* StringUtils.isNumericSpace("12 3") = true
* StringUtils.isNumericSpace("ab2c") = false
* StringUtils.isNumericSpace("12-3") = false
* StringUtils.isNumericSpace("12.3") = false
* </pre>
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if only contains digits or space,
* and is non-null
*/
public static boolean isNumericSpace(CharSequence cs) {
if (cs == null) {
return false;
}
int sz = cs.length();
for (int i = 0; i < sz; i++) {
if (Character.isDigit(cs.charAt(i)) == false && cs.charAt(i) != ' ') {
return false;
}
}
return true;
}
/**
* <p>Checks if the CharSequence contains only whitespace.</p>
*
* <p>{@code null} will return {@code false}.
* An empty CharSequence (length()=0) will return {@code true}.</p>
*
* <pre>
* StringUtils.isWhitespace(null) = false
* StringUtils.isWhitespace("") = true
* StringUtils.isWhitespace(" ") = true
* StringUtils.isWhitespace("abc") = false
* StringUtils.isWhitespace("ab2c") = false
* StringUtils.isWhitespace("ab-c") = false
* </pre>
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if only contains whitespace, and is non-null
*/
public static boolean isWhitespace(CharSequence cs) {
if (cs == null) {
return false;
}
int sz = cs.length();
for (int i = 0; i < sz; i++) {
if (Character.isWhitespace(cs.charAt(i)) == false) {
return false;
}
}
return true;
}
/**
* <p>Checks if the CharSequence contains only lowercase characters.</p>
*
* <p>{@code null} will return {@code false}.
* An empty CharSequence (length()=0) will return {@code false}.</p>
*
* <pre>
* StringUtils.isAllLowerCase(null) = false
* StringUtils.isAllLowerCase("") = false
* StringUtils.isAllLowerCase(" ") = false
* StringUtils.isAllLowerCase("abc") = true
* StringUtils.isAllLowerCase("abC") = false
* </pre>
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if only contains lowercase characters, and is non-null
*/
public static boolean isAllLowerCase(CharSequence cs) {
if (cs == null || isEmpty(cs)) {
return false;
}
int sz = cs.length();
for (int i = 0; i < sz; i++) {
if (Character.isLowerCase(cs.charAt(i)) == false) {
return false;
}
}
return true;
}
/**
* <p>Checks if the CharSequence contains only uppercase characters.</p>
*
* <p>{@code null} will return {@code false}.
* An empty String (length()=0) will return {@code false}.</p>
*
* <pre>
* StringUtils.isAllUpperCase(null) = false
* StringUtils.isAllUpperCase("") = false
* StringUtils.isAllUpperCase(" ") = false
* StringUtils.isAllUpperCase("ABC") = true
* StringUtils.isAllUpperCase("aBC") = false
* </pre>
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if only contains uppercase characters, and is non-null
*/
public static boolean isAllUpperCase(CharSequence cs) {
if (cs == null || isEmpty(cs)) {
return false;
}
int sz = cs.length();
for (int i = 0; i < sz; i++) {
if (Character.isUpperCase(cs.charAt(i)) == false) {
return false;
}
}
return true;
}
// Defaults
//-----------------------------------------------------------------------
/**
* <p>Returns either the passed in String,
* or if the String is {@code null}, an empty String ("").</p>
*
* <pre>
* StringUtils.defaultString(null) = ""
* StringUtils.defaultString("") = ""
* StringUtils.defaultString("bat") = "bat"
* </pre>
*
* @see ObjectUtils#toString(Object)
* @see String#valueOf(Object)
* @param str the String to check, may be null
* @return the passed in String, or the empty String if it
* was {@code null}
*/
public static String defaultString(String str) {
return str == null ? EMPTY : str;
}
/**
* <p>Returns either the passed in String, or if the String is
* {@code null}, the value of {@code defaultStr}.</p>
*
* <pre>
* StringUtils.defaultString(null, "NULL") = "NULL"
* StringUtils.defaultString("", "NULL") = ""
* StringUtils.defaultString("bat", "NULL") = "bat"
* </pre>
*
* @see ObjectUtils#toString(Object,String)
* @see String#valueOf(Object)
* @param str the String to check, may be null
* @param defaultStr the default String to return
* if the input is {@code null}, may be null
* @return the passed in String, or the default if it was {@code null}
*/
public static String defaultString(String str, String defaultStr) {
return str == null ? defaultStr : str;
}
/**
* <p>Returns either the passed in CharSequence, or if the CharSequence is
* empty or {@code null}, the value of {@code defaultStr}.</p>
*
* <pre>
* StringUtils.defaultIfEmpty(null, "NULL") = "NULL"
* StringUtils.defaultIfEmpty("", "NULL") = "NULL"
* StringUtils.defaultIfEmpty(" ", "NULL") = " "
* StringUtils.defaultIfEmpty("bat", "NULL") = "bat"
* StringUtils.defaultIfEmpty("", null) = null
* </pre>
* @param <T> the specific kind of CharSequence
* @param str the CharSequence to check, may be null
* @param defaultStr the default CharSequence to return
* if the input is empty ("") or {@code null}, may be null
* @return the passed in CharSequence, or the default
*/
public static <T extends CharSequence> T defaultIfEmpty(T str, T defaultStr) {
return isEmpty(str) ? defaultStr : str;
}
// Reversing
//-----------------------------------------------------------------------
/**
* <p>Reverses a String as per {@link StringBuilder#reverse()}.</p>
*
* <p>A {@code null} String returns {@code null}.</p>
*
* <pre>
* StringUtils.reverse(null) = null
* StringUtils.reverse("") = ""
* StringUtils.reverse("bat") = "tab"
* </pre>
*
* @param str the String to reverse, may be null
* @return the reversed String, {@code null} if null String input
*/
public static String reverse(String str) {
if (str == null) {
return null;
}
return new StringBuilder(str).reverse().toString();
}
// Abbreviating
//-----------------------------------------------------------------------
/**
* <p>Abbreviates a String using ellipses. This will turn
* "Now is the time for all good men" into "Now is the time for..."</p>
*
* <p>Specifically:
* <ul>
* <li>If {@code str} is less than {@code maxWidth} characters
* long, return it.</li>
* <li>Else abbreviate it to {@code (substring(str, 0, max-3) + "...")}.</li>
* <li>If {@code maxWidth} is less than {@code 4}, throw an
* {@code IllegalArgumentException}.</li>
* <li>In no case will it return a String of length greater than
* {@code maxWidth}.</li>
* </ul>
* </p>
*
* <pre>
* StringUtils.abbreviate(null, *) = null
* StringUtils.abbreviate("", 4) = ""
* StringUtils.abbreviate("abcdefg", 6) = "abc..."
* StringUtils.abbreviate("abcdefg", 7) = "abcdefg"
* StringUtils.abbreviate("abcdefg", 8) = "abcdefg"
* StringUtils.abbreviate("abcdefg", 4) = "a..."
* StringUtils.abbreviate("abcdefg", 3) = IllegalArgumentException
* </pre>
*
* @param str the String to check, may be null
* @param maxWidth maximum length of result String, must be at least 4
* @return abbreviated String, {@code null} if null String input
* @throws IllegalArgumentException if the width is too small
*/
public static String abbreviate(String str, int maxWidth) {
return abbreviate(str, 0, maxWidth);
}
/**
* <p>Abbreviates a String using ellipses. This will turn
* "Now is the time for all good men" into "...is the time for..."</p>
*
* <p>Works like {@code abbreviate(String, int)}, but allows you to specify
* a "left edge" offset. Note that this left edge is not necessarily going to
* be the leftmost character in the result, or the first character following the
* ellipses, but it will appear somewhere in the result.
*
* <p>In no case will it return a String of length greater than
* {@code maxWidth}.</p>
*
* <pre>
* StringUtils.abbreviate(null, *, *) = null
* StringUtils.abbreviate("", 0, 4) = ""
* StringUtils.abbreviate("abcdefghijklmno", -1, 10) = "abcdefg..."
* StringUtils.abbreviate("abcdefghijklmno", 0, 10) = "abcdefg..."
* StringUtils.abbreviate("abcdefghijklmno", 1, 10) = "abcdefg..."
* StringUtils.abbreviate("abcdefghijklmno", 4, 10) = "abcdefg..."
* StringUtils.abbreviate("abcdefghijklmno", 5, 10) = "...fghi..."
* StringUtils.abbreviate("abcdefghijklmno", 6, 10) = "...ghij..."
* StringUtils.abbreviate("abcdefghijklmno", 8, 10) = "...ijklmno"
* StringUtils.abbreviate("abcdefghijklmno", 10, 10) = "...ijklmno"
* StringUtils.abbreviate("abcdefghijklmno", 12, 10) = "...ijklmno"
* StringUtils.abbreviate("abcdefghij", 0, 3) = IllegalArgumentException
* StringUtils.abbreviate("abcdefghij", 5, 6) = IllegalArgumentException
* </pre>
*
* @param str the String to check, may be null
* @param offset left edge of source String
* @param maxWidth maximum length of result String, must be at least 4
* @return abbreviated String, {@code null} if null String input
* @throws IllegalArgumentException if the width is too small
*/
public static String abbreviate(String str, int offset, int maxWidth) {
if (str == null) {
return null;
}
if (maxWidth < 4) {
throw new IllegalArgumentException("Minimum abbreviation width is 4");
}
if (str.length() <= maxWidth) {
return str;
}
if (offset > str.length()) {
offset = str.length();
}
if (str.length() - offset < maxWidth - 3) {
offset = str.length() - (maxWidth - 3);
}
final String abrevMarker = "...";
if (offset <= 4) {
return str.substring(0, maxWidth - 3) + abrevMarker;
}
if (maxWidth < 7) {
throw new IllegalArgumentException("Minimum abbreviation width with offset is 7");
}
if (offset + maxWidth - 3 < str.length()) {
return abrevMarker + abbreviate(str.substring(offset), maxWidth - 3);
}
return abrevMarker + str.substring(str.length() - (maxWidth - 3));
}
/**
* <p>Abbreviates a String to the length passed, replacing the middle characters with the supplied
* replacement String.</p>
*
* <p>This abbreviation only occurs if the following criteria is met:
* <ul>
* <li>Neither the String for abbreviation nor the replacement String are null or empty </li>
* <li>The length to truncate to is less than the length of the supplied String</li>
* <li>The length to truncate to is greater than 0</li>
* <li>The abbreviated String will have enough room for the length supplied replacement String
* and the first and last characters of the supplied String for abbreviation</li>
* </ul>
* Otherwise, the returned String will be the same as the supplied String for abbreviation.
* </p>
*
* <pre>
* StringUtils.abbreviateMiddle(null, null, 0) = null
* StringUtils.abbreviateMiddle("abc", null, 0) = "abc"
* StringUtils.abbreviateMiddle("abc", ".", 0) = "abc"
* StringUtils.abbreviateMiddle("abc", ".", 3) = "abc"
* StringUtils.abbreviateMiddle("abcdef", ".", 4) = "ab.f"
* </pre>
*
* @param str the String to abbreviate, may be null
* @param middle the String to replace the middle characters with, may be null
* @param length the length to abbreviate {@code str} to.
* @return the abbreviated String if the above criteria is met, or the original String supplied for abbreviation.
*/
public static String abbreviateMiddle(String str, String middle, int length) {
if (isEmpty(str) || isEmpty(middle)) {
return str;
}
if (length >= str.length() || length < middle.length()+2) {
return str;
}
int targetSting = length-middle.length();
int startOffset = targetSting/2+targetSting%2;
int endOffset = str.length()-targetSting/2;
StringBuilder builder = new StringBuilder(length);
builder.append(str.substring(0,startOffset));
builder.append(middle);
builder.append(str.substring(endOffset));
return builder.toString();
}
// startsWith
//-----------------------------------------------------------------------
/**
* <p>Check if a CharSequence starts with a specified prefix.</p>
*
* <p>{@code null}s are handled without exceptions. Two {@code null}
* references are considered to be equal. The comparison is case sensitive.</p>
*
* <pre>
* StringUtils.startsWith(null, null) = true
* StringUtils.startsWith(null, "abc") = false
* StringUtils.startsWith("abcdef", null) = false
* StringUtils.startsWith("abcdef", "abc") = true
* StringUtils.startsWith("ABCDEF", "abc") = false
* </pre>
*
* @see String#startsWith(String)
* @param str the CharSequence to check, may be null
* @param prefix the prefix to find, may be null
* @return {@code true} if the CharSequence starts with the prefix, case sensitive, or
* both {@code null}
*/
public static boolean startsWith(CharSequence str, CharSequence prefix) {
return startsWith(str, prefix, false);
}
/**
* <p>Case insensitive check if a CharSequence starts with a specified prefix.</p>
*
* <p>{@code null}s are handled without exceptions. Two {@code null}
* references are considered to be equal. The comparison is case insensitive.</p>
*
* <pre>
* StringUtils.startsWithIgnoreCase(null, null) = true
* StringUtils.startsWithIgnoreCase(null, "abc") = false
* StringUtils.startsWithIgnoreCase("abcdef", null) = false
* StringUtils.startsWithIgnoreCase("abcdef", "abc") = true
* StringUtils.startsWithIgnoreCase("ABCDEF", "abc") = true
* </pre>
*
* @see String#startsWith(String)
* @param str the CharSequence to check, may be null
* @param prefix the prefix to find, may be null
* @return {@code true} if the CharSequence starts with the prefix, case insensitive, or
* both {@code null}
*/
public static boolean startsWithIgnoreCase(CharSequence str, CharSequence prefix) {
return startsWith(str, prefix, true);
}
/**
* <p>Check if a CharSequence starts with a specified prefix (optionally case insensitive).</p>
*
* @see String#startsWith(String)
* @param str the CharSequence to check, may be null
* @param prefix the prefix to find, may be null
* @param ignoreCase indicates whether the compare should ignore case
* (case insensitive) or not.
* @return {@code true} if the CharSequence starts with the prefix or
* both {@code null}
*/
private static boolean startsWith(CharSequence str, CharSequence prefix, boolean ignoreCase) {
if (str == null || prefix == null) {
return str == null && prefix == null;
}
if (prefix.length() > str.length()) {
return false;
}
return CharSequenceUtils.regionMatches(str, ignoreCase, 0, prefix, 0, prefix.length());
}
/**
* <p>Check if a CharSequence starts with any of an array of specified strings.</p>
*
* <pre>
* StringUtils.startsWithAny(null, null) = false
* StringUtils.startsWithAny(null, new String[] {"abc"}) = false
* StringUtils.startsWithAny("abcxyz", null) = false
* StringUtils.startsWithAny("abcxyz", new String[] {""}) = false
* StringUtils.startsWithAny("abcxyz", new String[] {"abc"}) = true
* StringUtils.startsWithAny("abcxyz", new String[] {null, "xyz", "abc"}) = true
* </pre>
*
* @param string the CharSequence to check, may be null
* @param searchStrings the CharSequences to find, may be null or empty
* @return {@code true} if the CharSequence starts with any of the the prefixes, case insensitive, or
* both {@code null}
*/
public static boolean startsWithAny(CharSequence string, CharSequence... searchStrings) {
if (isEmpty(string) || ArrayUtils.isEmpty(searchStrings)) {
return false;
}
for (CharSequence searchString : searchStrings) {
if (StringUtils.startsWith(string, searchString)) {
return true;
}
}
return false;
}
// endsWith
//-----------------------------------------------------------------------
/**
* <p>Check if a CharSequence ends with a specified suffix.</p>
*
* <p>{@code null}s are handled without exceptions. Two {@code null}
* references are considered to be equal. The comparison is case sensitive.</p>
*
* <pre>
* StringUtils.endsWith(null, null) = true
* StringUtils.endsWith(null, "def") = false
* StringUtils.endsWith("abcdef", null) = false
* StringUtils.endsWith("abcdef", "def") = true
* StringUtils.endsWith("ABCDEF", "def") = false
* StringUtils.endsWith("ABCDEF", "cde") = false
* </pre>
*
* @see String#endsWith(String)
* @param str the CharSequence to check, may be null
* @param suffix the suffix to find, may be null
* @return {@code true} if the CharSequence ends with the suffix, case sensitive, or
* both {@code null}
*/
public static boolean endsWith(CharSequence str, CharSequence suffix) {
return endsWith(str, suffix, false);
}
/**
* <p>Case insensitive check if a CharSequence ends with a specified suffix.</p>
*
* <p>{@code null}s are handled without exceptions. Two {@code null}
* references are considered to be equal. The comparison is case insensitive.</p>
*
* <pre>
* StringUtils.endsWithIgnoreCase(null, null) = true
* StringUtils.endsWithIgnoreCase(null, "def") = false
* StringUtils.endsWithIgnoreCase("abcdef", null) = false
* StringUtils.endsWithIgnoreCase("abcdef", "def") = true
* StringUtils.endsWithIgnoreCase("ABCDEF", "def") = true
* StringUtils.endsWithIgnoreCase("ABCDEF", "cde") = false
* </pre>
*
* @see String#endsWith(String)
* @param str the CharSequence to check, may be null
* @param suffix the suffix to find, may be null
* @return {@code true} if the CharSequence ends with the suffix, case insensitive, or
* both {@code null}
*/
public static boolean endsWithIgnoreCase(CharSequence str, CharSequence suffix) {
return endsWith(str, suffix, true);
}
/**
* <p>Check if a CharSequence ends with a specified suffix (optionally case insensitive).</p>
*
* @see String#endsWith(String)
* @param str the CharSequence to check, may be null
* @param suffix the suffix to find, may be null
* @param ignoreCase indicates whether the compare should ignore case
* (case insensitive) or not.
* @return {@code true} if the CharSequence starts with the prefix or
* both {@code null}
*/
private static boolean endsWith(CharSequence str, CharSequence suffix, boolean ignoreCase) {
if (str == null || suffix == null) {
return str == null && suffix == null;
}
if (suffix.length() > str.length()) {
return false;
}
int strOffset = str.length() - suffix.length();
return CharSequenceUtils.regionMatches(str, ignoreCase, strOffset, suffix, 0, suffix.length());
}
/**
* <p>Check if a CharSequence ends with any of an array of specified strings.</p>
*
* <pre>
* StringUtils.endsWithAny(null, null) = false
* StringUtils.endsWithAny(null, new String[] {"abc"}) = false
* StringUtils.endsWithAny("abcxyz", null) = false
* StringUtils.endsWithAny("abcxyz", new String[] {""}) = true
* StringUtils.endsWithAny("abcxyz", new String[] {"xyz"}) = true
* StringUtils.endsWithAny("abcxyz", new String[] {null, "xyz", "abc"}) = true
* </pre>
*
* @param string the CharSequence to check, may be null
* @param searchStrings the CharSequences to find, may be null or empty
* @return {@code true} if the CharSequence ends with any of the the prefixes, case insensitive, or
* both {@code null}
*/
public static boolean endsWithAny(CharSequence string, CharSequence... searchStrings) {
if (isEmpty(string) || ArrayUtils.isEmpty(searchStrings)) {
return false;
}
for (CharSequence searchString : searchStrings) {
if (StringUtils.endsWith(string, searchString)) {
return true;
}
}
return false;
}
/**
* Converts a <code>byte[]</code> to a String using the specified character encoding.
*
* @param bytes
* the byte array to read from
* @param charsetName
* the encoding to use, if null then use the platform default
* @return a new String
* @throws UnsupportedEncodingException
* If the named charset is not supported
* @throws NullPointerException
* if the input is null
*/
public static String toString(byte[] bytes, String charsetName) throws UnsupportedEncodingException {
return charsetName == null ? new String(bytes) : new String(bytes, charsetName);
}
}