servlet request getQueryString 汉字的URI编码如何转码

JavaScript中编码有三种方法:escape、encodeURI、encodeURIComponent，地址栏中那些%XX就是汉字对应的字节被encodeURI编码格式转了。一个字节对应一个%

转换方式如下：

public void doGet(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {

String line = request.getQueryString();
  System.out.println(line);
  
  String isDecodeUrl = URLDecoder.decode(line, "UTF-8");//将带汉字的encodeURI编码转换成字节，然后用UTF-8格式对字节解码
  System.out.println(isDecodeUrl); 
  
  String reg = "[\\u4e00-\\u9fa5]+";//汉字的unicode范围
  StringBuilder chineseWord = new StringBuilder();
  Pattern p = Pattern.compile(reg);//匹配规则封装
  Matcher m = p.matcher(isDecodeUrl);//将匹配规则和要匹配的字符串组合生成匹配引擎
    while(m.find())
     chineseWord.append(m.group());//用正则取得所有汉字
  System.out.println(chineseWord.toString());

String cnm = URLEncoder.encode(chineseWord.toString(), "GBK");//将汉字用GBK编码转成字节，然后用encodeURI进行编码。
  System.out.println(cnm);
  
  isDecodeUrl = URLDecoder.decode(cnm, "GBK");//做个试验验证是不是能正常转回来
  System.out.println(isDecodeUrl);
  
  response.setCharacterEncoding("GBK");
  response.setHeader("Content-type","text/html;charset=GBK");
  PrintWriter out = response.getWriter();
  out.println(isDecodeUrl);
 }