Android端实现用户登录

首先是web端，新建一个servlet：Sign.java

和web端登录的servlet相似

package cn.edu.hpu.android;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import cn.edu.service.impl.CompetitorManager;import cn.edu.service.impl.CompetitorManagerImpl;public class Login extends HttpServlet {public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doPost(request, response);}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {response.setContentType("text/plain");response.setCharacterEncoding("UTF-8");CompetitorManager cm = new CompetitorManagerImpl();//得到Android端传来的数据String username = request.getParameter("username");String password = request.getParameter("password");//调用登录方法，判断用户名、密码是否匹配int flag = cm.checkLogin(username, password);if(flag != 0){response.getOutputStream().write("success".getBytes());}}}

Android端，新建一个class：

package cn.edu.hpu.utils;import java.io.InputStream;import java.net.HttpURLConnection;import java.net.URL;public class LoginService {public static int LoginConnectWeb(String username,String password) throws Exception {//String path = "http://10.48.57.119:8080/tennis_game/Login?username="+username+"&&password="+password;String path = "http://192.168.0.21:8080/tennis_game/Login?username="+username+"&&password="+password;//将path包装成一个URL对象URL url = new URL(path);//System.out.println(url);HttpURLConnection conn = (HttpURLConnection)url.openConnection();//设置超时时间conn.setReadTimeout(5000);//设置请求方式conn.setRequestMethod("GET");//判断请求是否成功if(conn.getResponseCode() == 200) {//流的工具类，专门从流中读取数据（返回的是二进制数据）InputStream inStream = conn.getInputStream();//返回json解析数据return parseJSON(inStream);}return 0;}private static int parseJSON(InputStream inStream) throws Exception {//StreamTool一个输入输出流类byte[] data = StreamTool.read(inStream);String json = new String(data);if(json.equals("success")) {return 1;}else{return 0;}}}

MainActivity.java

package com.example.login;import cn.edu.hpu.utils.LoginService;import android.os.Bundle;import android.os.StrictMode;import android.annotation.SuppressLint;import android.app.Activity;import android.content.Intent;import android.content.SharedPreferences;import android.content.SharedPreferences.Editor;import android.view.View;import android.view.View.OnClickListener;import android.view.Window;import android.widget.Button;import android.widget.CheckBox;import android.widget.EditText;import android.widget.Toast;@SuppressLint("NewApi")public class MainActivity extends Activity {private Button login;private Button register;private EditText name,pwd;private CheckBox remember, login_auto;@Overrideprotected void onCreate(Bundle savedInstanceState) {this.requestWindowFeature(Window.FEATURE_NO_TITLE);//去除标题栏super.onCreate(savedInstanceState);StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder().detectDiskReads().detectDiskWrites().detectNetwork().penaltyLog().build());StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder().detectLeakedSqlLiteObjects().detectLeakedClosableObjects().penaltyLog().penaltyDeath().build());setContentView(R.layout.activity_main);name = (EditText) findViewById(R.id.username);pwd = (EditText) findViewById(R.id.password);remember = (CheckBox) findViewById(R.id.remember);login_auto = (CheckBox) findViewById(R.id.login_auto);login = (Button) findViewById(R.id.login);login.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stubString username = name.getText().toString();String password = pwd.getText().toString();//利用SharedPreferences 保存用户的登录信息SharedPreferences sp =getSharedPreferences("FILE", MODE_PRIVATE);Editor editor = sp.edit();editor.putString("username", username);editor.commit();int s = 0;try{s = LoginService.LoginConnectWeb(username, password);if(s == 1) {Intent intent = new Intent(MainActivity.this,ZhuYeActivity.class);startActivity(intent);    Toast.makeText(getApplicationContext(), "登录成功", Toast.LENGTH_SHORT).show();    }else {    Toast.makeText(getApplicationContext(), "账号或密码错误请重新输入！", Toast.LENGTH_SHORT).show();    }} catch (Exception e) {// TODO Auto-generated catch blocke.printStackTrace();}}});register = (Button) findViewById(R.id.register);register.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {Intent intent = new Intent(MainActivity.this,RegisterActivity.class);startActivity(intent);}});}}

activity_main.xml中代码较长且比较简单，故省略