js解析后台map的json

A. js解析后台map转成的json方法

JavaBean(以User为例)转成json格式
1.转成JSONArray类型
User user = new User();
user.setUsername("cxl");
user.setPassword("1234");
JSONArray json = JSONArray.fromObject(user);
System.out.println(json);//[{"password":"1234","username":"cxl"}]
response.getWriter().print(json.toString());
在js文件取数据
$.getJSON("http://localhost:8080/jQueryDemo/servlet/UserServlet",null,function(data) {
alert(data[0].username);
alert(data[0].password);
});
2.转成JSONObject类型
JSONObject jsonObj = JSONObject.fromObject(user);
System.out.println(jsonObj);//{"password":"1234","username":"cxl"}
response.getWriter().print(jsonObj);
在js文件取数据
alert(data.username);
alert(data.password);

List转成json格式
List<User> users = new ArrayList<User>();
User user = new User();
user.setUsername("cxl");
user.setPassword("1234");
User u = new User();
u.setUsername("lhl");
u.setPassword("1234");
users.add(user);
users.add(u);
1.转成JSONArray类型
JSONArray json = JSONArray.fromObject(users);
System.out.println(json.toString());
//[{"password":"1234","username":"cxl"},{"password":"1234","username":"lhl"}]
response.getWriter().print(json.toString());
js中取数据：alert(alert(data[0].username));