javascript - JQuery ajax 函数发送正确的值。但 RestController 接收 null

Question

这些代码是我的spring boot项目的RestController，

@RestController
@RequestMapping(value="/rest/user")
public class UserRestController {

    @Autowired
    private UserService userService;

    @PostMapping("login")
    public ResponseEntity<Boolean> authenticated(@RequestBody User user) {

        System.out.println(user.getUsername() +":"+ user.getPassword()); //This line returns NULL password value

        Boolean blogin = userService.authenticate(user.getUsername(), user.getPassword());
        if(!blogin)
            return new ResponseEntity<Boolean>(blogin, HttpStatus.NOT_ACCEPTABLE);

        return new ResponseEntity<Boolean>(blogin, HttpStatus.OK);
    }
}

下面的代码是 JQuery ajax java 脚本代码。

function ajax_login_submit() {

    var user = {
            username: $("#username").val(),
            password: $("#password").val()
        }; 

    console.log(user);

    $.ajax({
        type: "POST",
        contentType: "application/json; charset=utf-8",
        url: "rest/user/login",
        data: JSON.stringify(user),
        dataType: 'json',
        success: function (data) {

            var resultJson = JSON.stringify(data);
            $('#helloUserDiv').html(resultJson);
            console.log("SUCCESS : ", data);
            alert(data);

        },
        error: function (e) {

            var resultJson = e.responseText;
            $('#helloUserDiv').html(resultJson);
            console.log("ERROR : ", e);
        }
    });
}

java脚本的

console.log(user);返回正确的值。

{"username":"joseph","password":"password"}

但是在RestController代码中，密码值丢失，“NULL”。System.out.println(user.getUsername() + ":"+ user.getPassword()); 行返回奇怪的值，"joseph:null"JQuery ajax方法是否可以不将json值传输到REST服务器？如果我犯了一些错误，请告诉我如何正确地将 json 值发送到 REST 服务器。

Answer 1

试试这个:

 $.ajax({
        type: "POST",
        contentType: "application/json",
        url: "rest/user/login",
        data: JSON.stringify({"username": $("#username").val(), "password": $("#password").val()}),
        dataType: 'json',
        success: function (data) {
            var resultJson = JSON.stringify(data);
            $('#helloUserDiv').html(resultJson);
            console.log("SUCCESS : ", data);
            alert(data);
        },
        error: function (e) {
            var resultJson = e.responseText;
            $('#helloUserDiv').html(resultJson);
            console.log("ERROR : ", e);
        }
});