JSON与Java对象的互相转换

• 例一（单个对象进行赋值）：

    @RequestMapping("test1.do")@ResponseBodypublic JSONObject test1(HttpServletRequest request, HttpServletResponse response) {JSONObject jsonObject = new JSONObject();jsonObject.put("key1", "value1");jsonObject.put("key2", "value2");jsonObject.put("key3", "value3");return jsonObject;}

• 例二（多个对象进行转换）：

    @RequestMapping("TestListQrcode.do")@ResponseBodypublic JSONObject TestListQrcode(HttpServletRequest request, HttpServletResponse response)throws Exception {//String user_phone = request.getParameter("user_phone");String user_phone ="13652458975";Qrcode qrcode = new Qrcode();qrcode.setUser_phone(user_phone);qrcode.setQrcode_type("普通型");List<Qrcode> list  = qrcodeService.selectQrcodeList(qrcode);//创建json集合//用的包：import net.sf.json.JSONArray;JSONArray jsonArray = JSONArray.fromObject(list);System.out.println(jsonArray.toString());JSONObject jsonObject = new JSONObject();jsonObject.put("code", 1);jsonObject.put("data", jsonArray.toString());return jsonObject;}

• 例三（字符串的拼接，我只在servlet中用过）：

    String value1 = "1";int value2 = count-1;System.out.println("给前面传的count："+value2);String photo_file = par[0] + "/" + par[1] + "/images";//进行拼凑json字符串String jsonStr ="{" + '"'+ "success" + '"'  +":" + '"' + value1 + '"' + ","+ '"' + "count" + '"' +":" + '"' + value2 + '"' + ","+ '"' + "photo_file" + '"' +":" + '"' + photo_file + '"' +"}" ;PrintWriter out =null ;out =response.getWriter() ;out.write(jsonStr);out.close();