java 로 구현한 escape unescape

어느 중국사이트에서 가져왔습니다.

주소

http://hi.baidu.com/ljzcome/blog/item/96bfa35801a60689800a183b.html

 

 

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 = "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("%u4e2d%u6587"));  
 }  
}