xUtils3 post方法传json参数

今天写程序的时候遇到了这个问题 记录一下

  String url = HTTP_URL+"add";

  User user = new User("张三", (long) 1);
  String json = JSON.toJSONString(user);
  RequestParams params = new RequestParams(url);
  
  params.setAsJsonContent(true);
  params.setBodyContent(json);

  x.http().post(params, new Callback.CommonCallback() {
                    @Override
                    public void onSuccess(String result) {
                        Toast.makeText(MainActivity.this, result, Toast.LENGTH_LONG).show();
                    }

                    @Override
                    public void onError(Throwable ex, boolean isOnCallback) {
                        Toast.makeText(MainActivity.this, ex.toString(), Toast.LENGTH_LONG).show();
                    }

                    @Override
                    public void onCancelled(CancelledException cex) {
                        Toast.makeText(MainActivity.this, "onCancelled", Toast.LENGTH_LONG).show();
                    }

                    @Override
                    public void onFinished() {
                        Toast.makeText(MainActivity.this, "onFinished", Toast.LENGTH_LONG).show();
                    }
                });

params.setAsJsonContent(true);
params.setBodyContent(json);
这两句是关键
后台部分代码

@RequestMapping("/add")
@ResponseBody
public List add(@RequestBody User user){  
    userService.add(user);
    return userService.findAll();
};