JAVA js的escape函数、解析用js encodeURI编码的字符串、utf8转gb2312的函数

public static String escape(String src) {
int i;
int j;
StringBuffer tmp = new StringBuffer();
tmp.ensureCapacity(src.length() * 6);
for (i = 0; i < src.length(); i++) {
j = src.charAt(i);
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();
}

String str="K.A%C3%A4%C2%B8%C2%B4%C3%A6%C2%97%C2%B6%C3%A4%C2%BE%C2%9B%C3%A5%C2%BA%C2%94%C3%A5%C2%95%C2%86";

//str=escape(java.net.URLDecoder.decode(str,"utf-8"));
//System.out.println(java.net.URLDecoder.decode(str,"utf-8"));

str= (java.net.URLDecoder.decode(str,"utf-8"));
System.out.println(utf8Togb2312(str));

private static String utf8Togb2312(String str){
StringBuffer sb = new StringBuffer();
for(int i=0; i<str.length(); i++) {
char c = str.charAt(i);
switch (c) {
case '+':
sb.append(' ');
break;
case '%':
try {
sb.append((char)Integer.parseInt(
str.substring(i+1,i+3),16));
}
catch (NumberFormatException e) {
throw new IllegalArgumentException();
}
i += 2;
break;
default:
sb.append(c);
break;
}
}
// Undo conversion to external encoding
String result = sb.toString();
String res=null;
try{
byte[] inputBytes = result.getBytes("8859_1");
res= new String(inputBytes,"UTF-8");
}
catch(Exception e){}
return res;
}