The background can only receive get requests, and the data received by post is null,. What is wrong with this?

problem description

the backend can only receive get requests, and the data received by post is null

the environmental background of the problems and what methods you have tried

take a look at the break point. The value passed by the post request is null
tested with postman. I thought it was a problem with the testing software. Then I wrote a form form test, and the result is the same.
cannot receive data using post.

related codes

/ / Please paste the code text below (do not replace the code with pictures)

@RequestMapping(value = "login.do", method = RequestMethod.GET)
@ResponseBody
public ServerResponse<User> login(String username,String password, HttpSession session){
    ServerResponse<User> response = iUserService.login(username,password);
    if(response.isSuccess()){
        session.setAttribute(Const.CURRENT_USER,response.getData());
    }

    return response;
}

what result do you expect? What is the error message actually seen?

username and password should be able to receive the value passed by the front end
, but actually not. The value is null

let params = new FormData(); params.append('username', 'test'); params.append('password', 'test'); let config = { headers: {'content-type': 'application/x-www-form-urlencoded'} }; // axios.post('login.do', params, config).then((response) => { console.log(response.data); })