java實現javascript中的escape和unescape函數

/**


java實現javascript中的escape和unescape函數
多用于URL編碼與解碼
*/
public class EscapeUnescape {
 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();

}
public static void main(String[] args) {

 String tmp = "測試！";

 System.out.println("編碼：   " + escape(tmp));
 System.out.println("解碼：   " + unescape(tmp));

}
}</pre>