SpringBoot 获取前端传递Json的几种方法

var val = {id: 1, name: "小明"};
$.ajax({
    url: "/getJson",
    dataType: "JSON",
    type: "post",
    contentType: ‘application/json;charset=UTF-8‘,
    data: JSON.stringify(val),
    success: function (msg) {
        console.log(msg)
    }
})

@PostMapping("/getJson")
@ResponseBody
public Map<String,Object> getJsonVal(@RequestBody Map<String,Object> user) {
    System.out.println("user = " + user.get("id"));
    System.out.println("user = " + user.get("name"));
    return user;
}

@PostMapping("/getJson")
@ResponseBody
public User getJsonVal(@RequestBody User user) {
    return user;
}

var val = {"id": 1, "name": "小明"};
$.ajax({
    url: "/getJson",
    dataType: "JSON",
    type: "post",
    // contentType: ‘application/json;charset=UTF-8‘, //不能加
    data: val,
    success: function (msg) {
        console.log(msg)
    }
})

@PostMapping("/getJson")
@ResponseBody
public User getJsonVal(@RequestParam("id") String id,@RequestParam("name") String name) {
    User user = new User();
    user.setId(Integer.parseInt(id));
    user.setName(name);
    return user;
}

var val = [{"id": 1, "name": "小明"},{"id": 2, "name": "小红"}];
$.ajax({
    url: "/getJson",
    dataType: "JSON",
    type: "post",
    contentType: ‘application/json;charset=UTF-8‘, //不能加
    data: JSON.stringify(val),
    success: function (msg) {
        console.log(msg)
    }
})

@PostMapping("/getJson")
@ResponseBody
public List<User> getJsonVal(@RequestBody List<User> user) throws IOException {
    for(User user2 : user){
        System.out.println("user2 = " + user2);
    }
    return user;
}