java.net.URLEncode编码 与 URLDecode解码问题

String mytext = java.net.URLEncoder.encode("中国", "utf-8");

String mytext2 = java.net.URLDecoder.decode(mytext, "utf-8");

这两条语句在同一个页面中的话,得到的结果是:

mytext: %E4%B8%AD%E5%9B%BD

mytex2: 中国

String zhongguo=new String(request.getParameter("zhongguo").getBytes("iso8859_1"));

zhongguo=java.net.URLDecoder.decode(zhongguo,"utf-8");