JAVA字符串类

import java.util.*;
import java.util.regex.Pattern;
public class StrTools {
/**
* 分割字符串
*
* @param str String 原始字符串
* @param splitsign String 分隔符
* @return String[] 分割后的字符串数组
*/
@SuppressWarnings("unchecked")
public static String[] split(String str, String splitsign) {
int index;
if (str == null || splitsign == null)
return null;
ArrayList al = new ArrayList();
while ((index = str.indexOf(splitsign)) != -1) {
al.add(str.substring(0, index));
str = str.substring(index + splitsign.length());
}
al.add(str);
return (String[]) al.toArray(new String[0]);
}
/**
* 替换字符串
*
* @param from String 原始字符串
* @param to String 目标字符串
* @param source String 母字符串
* @return String 替换后的字符串
*/
public static String replace(String from, String to, String source) {
if (source == null || from == null || to == null)
return null;
StringBuffer bf = new StringBuffer("");
int index = -1;
while ((index = source.indexOf(from)) != -1) {
bf.append(source.substring(0, index) + to);
source = source.substring(index + from.length());
index = source.indexOf(from);
}
bf.append(source);
return bf.toString();
}
/**
* 替换字符串，能能够在HTML页面上直接显示(替换双引号和小于号)
*
* @param str String 原始字符串
* @return String 替换后的字符串
*/
public static String htmlencode(String str) {
if (str == null) {
return null;
}
return replace("\"", """, replace("<", "<", str));
}
/**
* 替换字符串，将被编码的转换成原始码（替换成双引号和小于号）
*
* @param str String
* @return String
*/
public static String htmldecode(String str) {
if (str == null) {
return null;
}
return replace(""", "\"", replace("<", "<", str));
}
private static final String _BR = "<br/>"