javascript 处理json相关 

 1 function showJSON() {   
 2     var user =   
 3      {   
 4         "username":"andy",   
 5         "age":20,   
 6         "info": { "tel": "123456", "cellphone": "98765"},   
 7         "address":   
 8              [   
 9                  {"city":"beijing","postcode":"222333"},   
10                  {"city":"newyork","postcode":"555666"}   
11              ]   
12      }   
13        
14      alert(user.username);   
15      alert(user.age);   
16      alert(user.info.cellphone);   
17      alert(user.address[0].city);   
18      alert(user.address[0].postcode);   
19 }   
 1 function showJSON() {   
 2     var user =   
 3      {   
 4         "username":"andy",   
 5         "age":20,   
 6         "info": { "tel": "123456", "cellphone": "98765"},   
 7         "address":   
 8              [   
 9                  {"city":"beijing","postcode":"222333"},   
10                  {"city":"newyork","postcode":"555666"}   
11              ]   
12      }   
13        
14      alert(user.username);   
15      alert(user.age);   
16      alert(user.info.cellphone);   
17      alert(user.address[0].city);   
18      alert(user.address[0].postcode);   
19        
20      user.username = "Tom";   
21      alert(user.username);   
22 }

JSON提供了json.js包，下载http://www.json.org/json.js 后，将其引入然后就可以简单的使用object.toJSONString()转换成JSON数据。

 1 function showCar() {   
 2     var carr = new Car("Dodge", "Coronet R/T", 1968, "yellow");   
 3      alert(carr.toJSONString());   
 4 }   
 5   
 6 function Car(make, model, year, color)        {   
 7      this.make   =   make;   
 8      this.model   =   model;   
 9      this.year   =   year;   
10      this.color   =   color;   
11 }

或者直接用eval来获得json对象，eval直接获得从后台获取的json str

function myEval() {   
    var str = '{ "name": "Violet", "occupation": "character" }';   
    var obj = eval('(' + str + ')');   
     alert(obj.toJSONString());   
}

或者使用parseJSON()方法

function myEval() {   
    var str = '{ "name": "Violet", "occupation": "character" }';   
    var obj = str.parseJSON();   
     alert(obj.toJSONString());   
}

prototype-1.5.1.js中提供了JSON的方法，String.evalJSON(), 可以不使用json.js, 修改上面的方法

function jsonResponse(originalRequest) {   
     alert(originalRequest.responseText);   
    var myobj = originalRequest.responseText.evalJSON(true);   
     alert(myobj.name);   
}

JSON还提供了java的jar包 http://www.json.org/java/index.html API也很简单，下面举个例子

function sendRequest() {   
    var carr = new Car("Dodge", "Coronet R/T", 1968, "yellow");   
    var pars = "car=" + carr.toJSONString();   
  
    var url = "/MyWebApp/JSONTest1";   
    var mailAjax = new Ajax.Request(   
         url,   
         {   
             method: 'get',   
             parameters: pars,   
             onComplete: jsonResponse   
         }   
     );   
}

使用JSON请求字符串就可以简单的生成JSONObject并进行解析,修改servlet添加JSON的处理(要使用json.jar)

private void doService(HttpServletRequest request, HttpServletResponse response) throws IOException {   
         String s3 = request.getParameter("car");   
        try {   
            JSONObject jsonObj = new JSONObject(s3);   
             System.out.println(jsonObj.getString("model"));   
             System.out.println(jsonObj.getInt("year"));   
         } catch (JSONException e) {   
             e.printStackTrace();   
         }   
         response.getWriter().print("{ \"name\": \"Violet\", \"occupation\": \"character\" }");   
     }

 

 

 

posted @ 2012-04-27 08:53  lostyue  阅读(338)  评论(0)  编辑  收藏  举报