package org.succlz123.utils;
/**
* <p>Operations on char primitives and Character objects.</p>
*
* <p>This class tries to handle {@code null} input gracefully.
* An exception will not be thrown for a {@code null} input.
* Each method documents its behaviour in more detail.</p>
*
* <p>#ThreadSafe#</p>
* @version $Id: CharUtils.java 1158279 2011-08-16 14:06:45Z ggregory $
*/
public class CharUtils {
/**
* {@code \u000a} linefeed LF ('\n').
*
* @see <a href="http://java.sun.com/docs/books/jls/third_edition/html/lexical.html#101089">JLF: Escape Sequences
* for Character and String Literals</a>
*/
public static final char LF = '\n';
/**
* {@code \u000d} carriage return CR ('\r').
*
* @see <a href="http://java.sun.com/docs/books/jls/third_edition/html/lexical.html#101089">JLF: Escape Sequences
* for Character and String Literals</a>
*/
public static final char CR = '\r';
/**
* <p>{@code CharUtils} instances should NOT be constructed in standard programming.
* Instead, the class should be used as {@code CharUtils.toString('c');}.</p>
*
* <p>This constructor is public to permit tools that require a JavaBean instance
* to operate.</p>
*/
public CharUtils() {
super();
}
//-----------------------------------------------------------------------
/**
* <p>Converts the character to the Integer it represents, throwing an
* exception if the character is not numeric.</p>
*
* <p>This method coverts the char '1' to the int 1 and so on.</p>
*
* <pre>
* CharUtils.toIntValue('3') = 3
* CharUtils.toIntValue('A') throws IllegalArgumentException
* </pre>
*
* @param ch the character to convert
* @return the int value of the character
* @throws IllegalArgumentException if the character is not ASCII numeric
*/
public static int toIntValue(char ch) {
if (ch < '0' || ch > '9') {
throw new IllegalArgumentException("The character " + ch + " is not in the range '0' - '9'");
}
return ch - 48;
}
/**
* <p>Converts the character to the Integer it represents, throwing an
* exception if the character is not numeric.</p>
*
* <p>This method coverts the char '1' to the int 1 and so on.</p>
*
* <pre>
* CharUtils.toIntValue('3', -1) = 3
* CharUtils.toIntValue('A', -1) = -1
* </pre>
*
* @param ch the character to convert
* @param defaultValue the default value to use if the character is not numeric
* @return the int value of the character
*/
public static int toIntValue(char ch, int defaultValue) {
if (ch < '0' || ch > '9') {
return defaultValue;
}
return ch - 48;
}
//--------------------------------------------------------------------------
/**
* <p>Converts the string to the Unicode format '\u0020'.</p>
*
* <p>This format is the Java source code format.</p>
*
* <pre>
* CharUtils.unicodeEscaped(' ') = "\u0020"
* CharUtils.unicodeEscaped('A') = "\u0041"
* </pre>
*
* @param ch the character to convert
* @return the escaped Unicode string
*/
public static String unicodeEscaped(char ch) {
if (ch < 0x10) {
return "\\u000" + Integer.toHexString(ch);
} else if (ch < 0x100) {
return "\\u00" + Integer.toHexString(ch);
} else if (ch < 0x1000) {
return "\\u0" + Integer.toHexString(ch);
}
return "\\u" + Integer.toHexString(ch);
}
/**
* <p>Converts the string to the Unicode format '\u0020'.</p>
*
* <p>This format is the Java source code format.</p>
*
* <p>If {@code null} is passed in, {@code null} will be returned.</p>
*
* <pre>
* CharUtils.unicodeEscaped(null) = null
* CharUtils.unicodeEscaped(' ') = "\u0020"
* CharUtils.unicodeEscaped('A') = "\u0041"
* </pre>
*
* @param ch the character to convert, may be null
* @return the escaped Unicode string, null if null input
*/
public static String unicodeEscaped(Character ch) {
if (ch == null) {
return null;
}
return unicodeEscaped(ch.charValue());
}
//--------------------------------------------------------------------------
/**
* <p>Checks whether the character is ASCII 7 bit.</p>
*
* <pre>
* CharUtils.isAscii('a') = true
* CharUtils.isAscii('A') = true
* CharUtils.isAscii('3') = true
* CharUtils.isAscii('-') = true
* CharUtils.isAscii('\n') = true
* CharUtils.isAscii('©') = false
* </pre>
*
* @param ch the character to check
* @return true if less than 128
*/
public static boolean isAscii(char ch) {
return ch < 128;
}
/**
* <p>Checks whether the character is ASCII 7 bit printable.</p>
*
* <pre>
* CharUtils.isAsciiPrintable('a') = true
* CharUtils.isAsciiPrintable('A') = true
* CharUtils.isAsciiPrintable('3') = true
* CharUtils.isAsciiPrintable('-') = true
* CharUtils.isAsciiPrintable('\n') = false
* CharUtils.isAsciiPrintable('©') = false
* </pre>
*
* @param ch the character to check
* @return true if between 32 and 126 inclusive
*/
public static boolean isAsciiPrintable(char ch) {
return ch >= 32 && ch < 127;
}
/**
* <p>Checks whether the character is ASCII 7 bit control.</p>
*
* <pre>
* CharUtils.isAsciiControl('a') = false
* CharUtils.isAsciiControl('A') = false
* CharUtils.isAsciiControl('3') = false
* CharUtils.isAsciiControl('-') = false
* CharUtils.isAsciiControl('\n') = true
* CharUtils.isAsciiControl('©') = false
* </pre>
*
* @param ch the character to check
* @return true if less than 32 or equals 127
*/
public static boolean isAsciiControl(char ch) {
return ch < 32 || ch == 127;
}
/**
* <p>Checks whether the character is ASCII 7 bit alphabetic.</p>
*
* <pre>
* CharUtils.isAsciiAlpha('a') = true
* CharUtils.isAsciiAlpha('A') = true
* CharUtils.isAsciiAlpha('3') = false
* CharUtils.isAsciiAlpha('-') = false
* CharUtils.isAsciiAlpha('\n') = false
* CharUtils.isAsciiAlpha('©') = false
* </pre>
*
* @param ch the character to check
* @return true if between 65 and 90 or 97 and 122 inclusive
*/
public static boolean isAsciiAlpha(char ch) {
return (ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z');
}
/**
* <p>Checks whether the character is ASCII 7 bit alphabetic upper case.</p>
*
* <pre>
* CharUtils.isAsciiAlphaUpper('a') = false
* CharUtils.isAsciiAlphaUpper('A') = true
* CharUtils.isAsciiAlphaUpper('3') = false
* CharUtils.isAsciiAlphaUpper('-') = false
* CharUtils.isAsciiAlphaUpper('\n') = false
* CharUtils.isAsciiAlphaUpper('©') = false
* </pre>
*
* @param ch the character to check
* @return true if between 65 and 90 inclusive
*/
public static boolean isAsciiAlphaUpper(char ch) {
return ch >= 'A' && ch <= 'Z';
}
/**
* <p>Checks whether the character is ASCII 7 bit alphabetic lower case.</p>
*
* <pre>
* CharUtils.isAsciiAlphaLower('a') = true
* CharUtils.isAsciiAlphaLower('A') = false
* CharUtils.isAsciiAlphaLower('3') = false
* CharUtils.isAsciiAlphaLower('-') = false
* CharUtils.isAsciiAlphaLower('\n') = false
* CharUtils.isAsciiAlphaLower('©') = false
* </pre>
*
* @param ch the character to check
* @return true if between 97 and 122 inclusive
*/
public static boolean isAsciiAlphaLower(char ch) {
return ch >= 'a' && ch <= 'z';
}
/**
* <p>Checks whether the character is ASCII 7 bit numeric.</p>
*
* <pre>
* CharUtils.isAsciiNumeric('a') = false
* CharUtils.isAsciiNumeric('A') = false
* CharUtils.isAsciiNumeric('3') = true
* CharUtils.isAsciiNumeric('-') = false
* CharUtils.isAsciiNumeric('\n') = false
* CharUtils.isAsciiNumeric('©') = false
* </pre>
*
* @param ch the character to check
* @return true if between 48 and 57 inclusive
*/
public static boolean isAsciiNumeric(char ch) {
return ch >= '0' && ch <= '9';
}
/**
* <p>Checks whether the character is ASCII 7 bit numeric.</p>
*
* <pre>
* CharUtils.isAsciiAlphanumeric('a') = true
* CharUtils.isAsciiAlphanumeric('A') = true
* CharUtils.isAsciiAlphanumeric('3') = true
* CharUtils.isAsciiAlphanumeric('-') = false
* CharUtils.isAsciiAlphanumeric('\n') = false
* CharUtils.isAsciiAlphanumeric('©') = false
* </pre>
*
* @param ch the character to check
* @return true if between 48 and 57 or 65 and 90 or 97 and 122 inclusive
*/
public static boolean isAsciiAlphanumeric(char ch) {
return (ch >= 'A' && ch <= 'Z') || (ch >= 'a' && ch <= 'z') || (ch >= '0' && ch <= '9');
}
}