SpringMVC method of passing JSON data

1. Use application/x-www-form-urlencoded to transfer data

The default format of Ajax is: application/x-www-form-urlencoded, which is equivalent to (username="admin"&password=123) to pass data (this is a fixed format for GET requests)

Front-end code:

当Ajax以默认格式上传时，data数据直接使用JSON对象user，不用转换为JSON字符串（很方便）
 var user= {
    
    
                "username" : username,
                "password" : password,
                "rememberMe":rememberMe
            };
$.ajax({
    
    
    url : "http://...../jsontest.do",
    type : "POST",
    data : user,
    dataType : 'json',
    success : function(data) {
    
    
    }
});

Backend code:

@RequestMapping("/jsontest.do")
public void test(User user,String username,String password,Boolean rememberMe){
    
    
    System.out.println(user);
    System.out.println("username: " + username);
    System.out.println("password: " + password);
    System.out.println("rememberMe: " + rememberMe);
    
}

Second, use application/json format to transfer data

Front-end code:

var user= {
    
    
                "username" : username,
                "password" : password
          };
$.ajax({
    
    
        url : "http://...../jsontest.do",
        type : "POST",
        async : true,
        contentType: "application/json; charset=utf-8",
        data : JSON.stringify(user),
        dataType : 'json',
        success : function(data) {
    
    
        }
 });

Backend code:

//必须使用@RequestBody 注解
@RequestMapping("/jsontest")
public void test(@RequestBody User user){
    
    
    String username = user.getUsername();
    String password = user.getPassword();
}

或者

@RequestMapping("/jsontest")
public void test(@RequestBody Map map){
    
    
    String username = map.get("username").toString();
    String password = map.get("password").toString();
}

或者

 public void test(@RequestBody String jsonData) {
    
    
    JSONObject jsonObject = JSON.parseObject(jsonData);
    String username= jsonObject.getString("username");
    String username= jsonObject.getString("password");
 }