java中的escape和unescape

      在js中，可以将url中的中文参数通过escape("中文")函数来将中文转换为unicode编码的字符串，即百分号+u+字母/数字。当服务器端未自动对其进行解码时，我们可以自己编写函数来进行转码，如下：

      public static String escape(String src) {  
        int i;  
        char j;  
        StringBuffer tmp = new StringBuffer();  
        tmp.ensureCapacity(src.length() * 6);  
        for (i = 0; i < src.length(); i++) {  
            j = src.charAt(i);  
            if (Character.isDigit(j) || Character.isLowerCase(j)  
                    || Character.isUpperCase(j))  
                tmp.append(j);  
            else if (j < 256) {  
                tmp.append("%");  
                if (j < 16)  
                    tmp.append("0");  
                tmp.append(Integer.toString(j, 16));  
            } else {  
                tmp.append("%u");  
                tmp.append(Integer.toString(j, 16));  
            }  
        }  
        return tmp.toString();  
    }  

    public static String unescape(String src) {  
        StringBuffer tmp = new StringBuffer();  
        tmp.ensureCapacity(src.length());  
        int lastPos = 0, pos = 0;  
        char ch;  
        while (lastPos < src.length()) {  
            pos = src.indexOf("%", lastPos);  
            if (pos == lastPos) {  
                if (src.charAt(pos + 1) == 'u') {  
                    ch = (char) Integer.parseInt(src  
                            .substring(pos + 2, pos + 6), 16);  
                    tmp.append(ch);  
                    lastPos = pos + 6;  
                } else {  
                    ch = (char) Integer.parseInt(src  
                            .substring(pos + 1, pos + 3), 16);  
                    tmp.append(ch);  
                    lastPos = pos + 3;  
                }  
            } else {  
                if (pos == -1) {  
                    tmp.append(src.substring(lastPos));  
                    lastPos = src.length();  
                } else {  
                    tmp.append(src.substring(lastPos, pos));  
                    lastPos = pos;  
                }  
            }  
        }  
        return tmp.toString();  
    }  

/**
* @disc 对字符串重新编码
* @param src
* @return
*/
public static String isoToGB(String src) {
   String strRet = null;
   try {
    strRet = new String(src.getBytes("ISO_8859_1"), "GB2312");
   } catch (Exception e) {

   }
   return strRet;
}

/**
* @disc 对字符串重新编码
* @param src
* @return
*/
public static String isoToUTF(String src) {
   String strRet = null;
   try {
    strRet = new String(src.getBytes("ISO_8859_1"), "UTF-8");
   } catch (Exception e) {

   }
   return strRet;
}


    public static void main(String[] args) {  
        String tmp = "中文";  
        System.out.println("testing escape : " + tmp);  
        tmp = escape(tmp);  
        System.out.println(tmp);  
        System.out.println("testing unescape :" + tmp);  
        System.out.println(unescape("%u6211%u4eec"));  
    }   

      当通过js使用escape()函数来转码url中的中文时，如果服务器端接受不到该中文参数，就改用encodeURI()函数来代替escape()函数。