怎么将UTF-8编码的字符串“%E5%93%88%E5%93%88”转化成的汉字

如何将UTF-8编码的字符串“%E5%93%88%E5%93%88”转化成的汉字？
如题，答案是“哈哈”

------解决方案--------------------
url纺码解码.
------解决方案--------------------
String s = "%E5%93%88%E5%93%88 ";
String str = URLDecoder.decode(s, "utf-8 ");
System.out.println(str);