/*
* Copyright (c) 2002-2012 Alibaba Group Holding Limited.
* All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.alibaba.toolkit.util;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.UnsupportedEncodingException;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.MissingResourceException;
import java.util.ResourceBundle;
import java.util.StringTokenizer;
/**
* 和字符串有关的小工具.
*
* @author Michael Zhou
* @version $Id: StringUtil.java,v 1.1 2003/07/03 07:26:15 baobao Exp $
*/
public class StringUtil {
private static final OutputStream DUMMY_OUTPUT_STREAM = new ByteArrayOutputStream(0);
private static final String SYSTEM_CHARSET = new OutputStreamWriter(DUMMY_OUTPUT_STREAM).getEncoding();
/*
* ==========================================================================
* ==
*/
/* 以下是有关resource bundle的方法 */
/*
* ==========================================================================
* ==
*/
/**
* 使用<code>MessageFormat</code>格式化字符串.
*
* @param bundle resource bundle
* @param key 要查找的键
* @param params 参数表
* @return key对应的字符串
* @throws NullPointerException resource key为<code>null</code>或resource
* bundle为<code>null</code>
* @throws MissingResourceException 指定resource key未找到
*/
public static String getMessage(ResourceBundle bundle, Object key, Object[] params) {
String pattern = bundle.getString(key.toString());
if (params == null || params.length == 0) {
return pattern;
}
return MessageFormat.format(pattern, params);
}
/**
* 使用<code>MessageFormat</code>格式化字符串.
*
* @param bundle resource bundle
* @param key 要查找的键
* @param param1 参数1
* @return key对应的字符串
* @throws NullPointerException resource key为<code>null</code>或resource
* bundle为<code>null</code>
* @throws MissingResourceException 指定resource key未找到
*/
public static String getMessage(ResourceBundle bundle, Object key, Object param1) {
return getMessage(bundle, key, new Object[] { param1 });
}
/**
* 使用<code>MessageFormat</code>格式化字符串.
*
* @param bundle resource bundle
* @param key 要查找的键
* @param param1 参数1
* @param param2 参数2
* @return key对应的字符串
* @throws NullPointerException resource key为<code>null</code>或resource
* bundle为<code>null</code>
* @throws MissingResourceException 指定resource key未找到
*/
public static String getMessage(ResourceBundle bundle, Object key, Object param1, Object param2) {
return getMessage(bundle, key, new Object[] { param1, param2 });
}
/**
* 使用<code>MessageFormat</code>格式化字符串.
*
* @param bundle resource bundle
* @param key 要查找的键
* @param param1 参数1
* @param param2 参数2
* @param param3 参数3
* @return key对应的字符串
* @throws NullPointerException resource key为<code>null</code>或resource
* bundle为<code>null</code>
* @throws MissingResourceException 指定resource key未找到
*/
public static String getMessage(ResourceBundle bundle, Object key, Object param1, Object param2, Object param3) {
return getMessage(bundle, key, new Object[] { param1, param2, param3 });
}
/**
* 使用<code>MessageFormat</code>格式化字符串.
*
* @param bundle resource bundle
* @param key 要查找的键
* @param param1 参数1
* @param param2 参数2
* @param param3 参数3
* @param param4 参数4
* @return key对应的字符串
* @throws NullPointerException resource key为<code>null</code>或resource
* bundle为<code>null</code>
* @throws MissingResourceException 指定resource key未找到
*/
public static String getMessage(ResourceBundle bundle, Object key, Object param1, Object param2, Object param3,
Object param4) {
return getMessage(bundle, key, new Object[] { param1, param2, param3, param4 });
}
/**
* 使用<code>MessageFormat</code>格式化字符串.
*
* @param bundle resource bundle
* @param key 要查找的键
* @param param1 参数1
* @param param2 参数2
* @param param3 参数3
* @param param4 参数4
* @param param5 参数5
* @return key对应的字符串
* @throws NullPointerException resource key为<code>null</code>或resource
* bundle为<code>null</code>
* @throws MissingResourceException 指定resource key未找到
*/
public static String getMessage(ResourceBundle bundle, Object key, Object param1, Object param2, Object param3,
Object param4, Object param5) {
return getMessage(bundle, key, new Object[] { param1, param2, param3, param4, param5 });
}
/**
* 检查字符串是否为<code>null</code>或空字符串.
*
* @param str 要检查的字符串
* @return 如果为空, 则返回<code>true</code>
*/
public static boolean isEmpty(String str) {
return str == null || str.length() == 0;
}
/**
* 取得系统字符集名称.
*
* @return 系统字符集名称
*/
public static String getSystemCharset() {
return SYSTEM_CHARSET;
}
/**
* 取得正规的字符集名称, 如果指定字符集不存在, 则抛出<code>UnsupportedEncodingException</code>.
*
* @param charset 字符集名称
* @return 正规的字符集名称
* @throws UnsupportedEncodingException 如果指定字符集不存在
*/
public static String getCanonicalCharset(String charset) throws UnsupportedEncodingException {
return new OutputStreamWriter(DUMMY_OUTPUT_STREAM, charset).getEncoding();
}
/**
* 取得正规的字符集名称, 如果指定字符集不存在, 则返回<code>null</code>.
*
* @param charset 字符集名称
* @return 正规的字符集名称, 如果指定字符集不存在, 则返回<code>null</code>
*/
public static String getCanonicalCharsetQuiet(String charset) {
try {
return getCanonicalCharset(charset);
} catch (UnsupportedEncodingException e) {
return null;
}
}
/**
* 展开字符串, 将"$｛"和"｝"中的变量转换成<code>System.getProperties()</code>中的值.
*
* @param value 要转换的值
* @return 展开后的值
*/
public static String expendProperty(String value) {
return expendProperty(value, System.getProperties());
}
/**
* 展开字符串, 将"$｛"和"｝"中的变量转换成指定properties中的值.
*
* @param value 要转换的值
* @param properties 可用的变量
* @return 展开后的值
*/
public static String expendProperty(String value, Map properties) {
if (value == null) {
return null;
}
int i = value.indexOf("${", 0);
if (i == -1) {
return value;
}
StringBuffer buffer = new StringBuffer(value.length());
int length = value.length();
int j = 0;
while (i < length) {
if (i > j) {
buffer.append(value.substring(j, i));
j = i;
}
int k;
for (k = i + 2; k < length && value.charAt(k) != '}'; k++) {
}
if (k == length) {
buffer.append(value.substring(i, k));
break;
}
String propertyName = value.substring(i + 2, k);
if (propertyName.equals("/")) {
buffer.append(File.separatorChar);
} else {
Object propertyValue = properties.get(propertyName);
if (propertyValue != null) {
buffer.append(propertyValue);
} else {
buffer.append("${").append(propertyName).append("}");
}
}
j = k + 1;
i = value.indexOf("${", j);
if (i == -1) {
if (j < length) {
buffer.append(value.substring(j, length));
}
break;
}
}
return buffer.toString();
}
// add by roy
/**
* 根据分割符分割字符串。 Return List,after split Split a String by a splitter(such as
* ",","hai",...)
*
* @param sStr 将要被分割的字符串。
* @param sSplitter 分割符。
* @return 一个含有分割好的字符串的List。如果分割失败将返回null,如果字符串中没有包含指定的分割符，
* 将返回只有一个元素的字符串数组，这个元素就是该字符串本身。如果这个字符串只含有分割符，将返回null。
*/
public static List splitStr(String sStr, String sSplitter) {
if (sStr == null || sStr.length() <= 0 || sSplitter == null || sSplitter.length() <= 0) {
return null;
}
StringTokenizer st = new StringTokenizer(sStr, sSplitter);
List result = new ArrayList();
while (st.hasMoreTokens()) {
result.add(st.nextToken().trim());
}
return result;
}
// add by roy
/**
* 检验一个String是否是一个数字（例如：7897897->true,789t67 -> false）。
* 注意：如果是一个负数，将会返回false. Return true if the string represents a number
*
* @param str 你想校验的字符串。
* @return 如果是一个标准的数字，将返回true，否则返回false。
*/
public static boolean isNum(String str) {
if (str == null || str.length() <= 0) {
return false;
}
char[] ch = str.toCharArray();
for (int i = 0; i < str.length(); i++) {
if (!Character.isDigit(ch[i])) {
return false;
}
}
return true;
}
}