android studio 自帶的LoginActivity 添加登陸

新手入門，想看看AS自帶的DEMO怎么寫的，於是在AS中新建工程時選擇了LoginActivity。關於LoginActivity的分析，網上可以找到。直接上我改過的代碼。 

package com.example.myapplication.data;

import android.util.Log;

import com.example.myapplication.data.model.LoggedInUser;
import com.example.myapplication.data.model.Token;
import com.google.gson.Gson;
import com.squareup.okhttp.FormEncodingBuilder;
import com.squareup.okhttp.OkHttpClient;
import com.squareup.okhttp.Request;
import com.squareup.okhttp.RequestBody;
import com.squareup.okhttp.Response;

import java.io.IOException;

/**
 * Class that handles authentication w/ login credentials and retrieves user information.
 */
public class LoginDataSource{

    public LoginDataSource() {

    }

    public Result<LoggedInUser> login(String username, String password) {

        try {
            // TODO: handle loggedInUser authentication
            //Demo中這個地方直接返回fakeUser，我在這里加入了用戶驗證過程
            HttpLogin httpLogin = new HttpLogin("http://local.me/api/login",username,password);
            Thread t1 = new Thread(new Runnable() {
                public void run() {
                    httpLogin.login();
                }
            });
            t1.start();
            try {
                t1.join();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }

            LoggedInUser fakeUser =
                    new LoggedInUser(
                            httpLogin.getResultData(),
                            httpLogin.getResultData());
            return new Result.Success<>(fakeUser);
        } catch (Exception e) {
            return new Result.Error(new IOException("Error logging in", e));
        }
    }

    public void logout() {
        // TODO: revoke authentication
    }

    //登陸類，返回結果保存在resultData中
    private class HttpLogin {
        public HttpLogin(String url, String username, String password) {
            this.url = url;
            this.username = username;
            this.password = password;
            requestBody = new FormEncodingBuilder()
                    .add("username", username)
                    .add("password", password)
                    .build();
            /*Request request = new Request.Builder()
                    .url(this.url)
                    .post(requestBody)//添加post請求
                    .build();*/
            resultData = null;
        }

        private String url ;
        private String username ;
        private String password ;

        public String getResultData() {
            return resultData;
        }

        private String resultData;
        OkHttpClient okHttpClient = new OkHttpClient();
        RequestBody requestBody ;
        Request request ;

        public void login() {
            final Request request = new Request.Builder()
                    .url(this.url)
                    .post(requestBody)//添加post請求
                    .build();
            try {                final Response response = okHttpClient.newCall(request).execute();
                final String resultData = response.body().string();
                Log.d("loginResultData",resultData);
                this.resultData = resultData;

            }
            catch (Exception e){
                e.printStackTrace();
            }
        }
    }
}