Android客户端与服务端交互之登陆示例

Android客户端与服务端交互之登陆示例

今天了解了一下android客户端与服务端是怎样交互的，发现其实跟web有点类似吧，然后网上找了大神的登陆示例，是基于IntentService的

1.后台使用简单的servlet，支持GET或POST。这个servlet最终返回给前台一个字符串flag，值是true或false，表示登录是否成功。

servlet使用之前需要配置，主义servlet的servlet-name要和servlet-mapping的servlet-name一致，否则找不到路径

我是在myEclipse上创建的一个web service 项目，然后部署到tomcat服务器上以便android客户端访问

<servlet>
        <servlet-name>helloWorld</servlet-name>
        <servlet-class>com.zhongzhong.wap.action.HelloServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>helloWorld</servlet-name>
        <url-pattern>/queryOrder</url-pattern>
    </servlet-mapping>

import java.io.IOException;
import java.io.PrintWriter;
 
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
 
import com.zhongzhong.wap.bean.UserBean;
 
public class HelloServlet extends HttpServlet {
 
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
        doPost(req, resp);
    }
 
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp)
            throws ServletException, IOException {
         
         resp.setContentType(text/html); 
            PrintWriter out = resp.getWriter(); 
            Boolean flag = false;   
            String userName = req.getParameter(un); 
            String password = req.getParameter(pw);  
            if(userName.equals(htp)&&password.equals(123))
            {
                flag = true;
            }
             
            else flag = false;
            System.out.println(userName:+userName+ password:+password);
            out.print(flag); 
            out.flush(); 
            out.close();
    }
 
}

2.然后我是在安卓的ADT上创建一个安卓项目，建立两个Activity，分别作为登录界面和登录成功界面。

1 <relativelayout
 android:layout_height="match_parent" 
android:layout_width="match_parent" 
android:paddingbottom="@dimen/activity_vertical_margin" 
android:paddingleft="@dimen/activity_horizontal_margin" 
android:paddingright="@dimen/activity_horizontal_margin" 
android:paddingtop="@dimen/activity_vertical_margin" 
tools:context=".MainActivity" 
xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools">
 2  
 3     <textview android:id="@+id/textView1" 
android:layout_alignparenttop="true" 
android:layout_centerhorizontal="true" 
android:layout_height="wrap_content" 
android:layout_margintop="40dp"
 android:layout_width="wrap_content"android:text="HelloWorld登陆示例">
  
<edittext 
　  android:ems="10" 
 android:hint="请输入账号" 
 android:id="@+id/et_user" 
 android:layout_below="@+id/textView1"
 android:layout_centerhorizontal="true" 
 android:layout_height="wrap_content"
 android:layout_margintop="33dp" 
 android:layout_width="wrap_content">
  
  <requestfocus>
 </requestfocus>
</edittext>
  
<edittext 
    android:ems="10" 
 android:hint="请输入密码" 
 android:id="@+id/et_psw" 
 android:inputtype="textPassword" 
 android:layout_below="@+id/et_user" 
 android:layout_centerhorizontal="true" 
 android:layout_height="wrap_content" 
 android:layout_margintop="40dp" 
 android:layout_width="wrap_content">

<button 
　　android:id="@+id/btn_login" 
android:layout_below="@+id/et_psw" 
android:layout_centerhorizontal="true"
 android:layout_height="wrap_content" 
android:layout_margintop="37dp"
 android:layout_width="wrap_content" 
android:text="登陆">
</button>
</edittext>
</textview>
</relativelayout>

 <relativelayout android:layout_height="match_parent" android:layout_width="match_parent" android:paddingbottom="@dimen/activity_vertical_margin" android:paddingleft="@dimen/activity_horizontal_margin" android:paddingright="@dimen/activity_horizontal_margin" android:paddingtop="@dimen/activity_vertical_margin" tools:context=".NaviActivity" xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools">
  
     <textview android:layout_alignparenttop="true" android:layout_centerhorizontal="true" android:layout_height="wrap_content" android:layout_margintop="46dp" android:layout_width="wrap_content" android:text="登陆成功">
  
 </textview></relativelayout>

3.HTTP的访问公共类，用于处理GET和POST请求

package com.example.logindemo;
 
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
 
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
 
import android.content.Entity;
import android.util.Log;
 
public class HttpUtil {
    // 创建HttpClient对象
    public static HttpClient httpClient = new DefaultHttpClient();
    public static final String BASE_URL = http://192.168.3.14:8090/HelloWord/;
 
    /**
     *
     * @param url
     *            发送请求的URL
     * @return 服务器响应字符串
     * @throws Exception
     */
    public static String getRequest(String url) throws Exception {
        // 创建HttpGet对象。
        HttpGet get = new HttpGet(url);
        // 发送GET请求
        HttpResponse httpResponse = httpClient.execute(get);
        // 如果服务器成功地返回响应
        if (httpResponse.getStatusLine().getStatusCode() == 200) {
            // 获取服务器响应字符串
            String result = EntityUtils.toString(httpResponse.getEntity());
            return result;
        } else {
            Log.d(服务器响应代码, (new Integer(httpResponse.getStatusLine()
                    .getStatusCode())).toString());
            return null;
        }
    }
 
    /**
     *
     * @param url
     *            发送请求的URL
     * @param params
     *            请求参数
     * @return 服务器响应字符串
     * @throws Exception
     */
    public static String postRequest(String url, Map<string, string=""> rawParams)
            throws Exception {
        // 创建HttpPost对象。
        HttpPost post = new HttpPost(url);
        // 如果传递参数个数比较多的话可以对传递的参数进行封装
        List<namevaluepair> params = new ArrayList<namevaluepair>();
        for (String key : rawParams.keySet()) {
            // 封装请求参数
            params.add(new BasicNameValuePair(key, rawParams.get(key)));
        }
        // 设置请求参数
        post.setEntity(new UrlEncodedFormEntity(params, UTF-8));
        // 发送POST请求
        HttpResponse httpResponse = httpClient.execute(post);
        // 如果服务器成功地返回响应
        if (httpResponse.getStatusLine().getStatusCode() == 200) {
            // 获取服务器响应字符串
            String result = EntityUtils.toString(httpResponse.getEntity());
            return result;
        }
        return null;
    }
}
</namevaluepair></namevaluepair></string,>

4.IntentService服务，用于在后台以队列方式处理耗时操作。

package com.example.logindemo;
 
import java.util.HashMap;
 
import android.app.IntentService;
import android.content.Intent;
import android.util.Log;
 
public class ConnectService extends IntentService {
    private static final String ACTION_RECV_MSG = com.example.logindemo.action.RECEIVE_MESSAGE;
 
    public ConnectService() {
        super(TestIntentService);
        // TODO Auto-generated constructor stub
    }
     
    @Override
    protected void onHandleIntent(Intent intent) {
        // TODO Auto-generated method stub
        /**
         * 经测试，IntentService里面是可以进行耗时的操作的 
         * IntentService使用队列的方式将请求的Intent加入队列，
         * 然后开启一个worker thread(线程)来处理队列中的Intent  
         * 对于异步的startService请求，IntentService会处理完成一个之后再处理第二个  
         */ 
        Boolean flag = false; 
        //通过intent获取主线程传来的用户名和密码字符串 
        String username = intent.getStringExtra(username); 
        String password = intent.getStringExtra(password); 
        flag = doLogin(username, password); 
        Log.d(登录结果, flag.toString()); 
           
        Intent broadcastIntent = new Intent(); 
        broadcastIntent.setAction(ACTION_RECV_MSG);   
        broadcastIntent.addCategory(Intent.CATEGORY_DEFAULT);   
        broadcastIntent.putExtra(result, flag.toString()); 
        sendBroadcast(broadcastIntent); 
 
    }
     
     // 定义发送请求的方法 
    private Boolean doLogin(String username, String password) 
    { 
        String strFlag = ; 
        // 使用Map封装请求参数 
        HashMap<string, string=""> map = new HashMap<string, string="">(); 
        map.put(un, username); 
        map.put(pw, password); 
        // 定义发送请求的URL 
      String url = HttpUtil.BASE_URL + queryOrder?un= + username + &pw= + password;  //GET方式 
       // String url = HttpUtil.BASE_URL + LoginServlet; //POST方式 
        Log.d(url, url); 
        Log.d(username, username); 
        Log.d(password, password); 
        try { 
            // 发送请求 
            strFlag = HttpUtil.postRequest(url, map);  //POST方式 
//          strFlag = HttpUtil.getRequest(url);  //GET方式 
            Log.d(服务器返回值, strFlag); 
        } catch (Exception e) { 
            // TODO Auto-generated catch block 
            e.printStackTrace(); 
        } 
           
        if(strFlag.trim().equals(true)){ 
            return true; 
        }else{ 
            return false; 
        } 
           
    } 
}
</string,></string,>

 

5。在AndroidManifest.xml中注册IntentService。注意uses-permission节点，为程序开启访问网络的权限。

<!--?xml version=1.0 encoding=utf-8?-->
<manifest android:versioncode="1" android:versionname="1.0" package="com.example.logindemo" xmlns:android="http://schemas.android.com/apk/res/android">
 
    <uses-sdk android:minsdkversion="8" android:targetsdkversion="18">
 
    <uses-permission android:name="android.permission.INTERNET">
 
     
         
            <intent-filter>
                 
 
                <category android:name="android.intent.category.LAUNCHER">
            </category></action></intent-filter>
        </activity>
         
        </activity>
 
        <service android:name="com.example.logindemo.ConnectService">
        </service>
    </application>
 
</uses-permission></uses-sdk></manifest>

 

6.登陆界面处理，注意

1. 按钮监听事件中，使用Intent将要传递的值传给service。接收广播类中，同样使用Intent将要传递的值传给下一个Activity。在onCreate()中，动态注册接收广播类的实例receiver。在接收广播类中，不要使用完毕后忘记注销接收器，否则会报一个Are you missing a call to unregisterReceiver()? 的异常。
   

   package com.example.logindemo;
    
   import android.os.Bundle;
   import android.app.Activity;
   import android.content.BroadcastReceiver;
   import android.content.Context;
   import android.content.Intent;
   import android.content.IntentFilter;
   import android.util.Log;
   import android.view.Menu;
   import android.view.View;
   import android.view.View.OnClickListener;
   import android.widget.Button;
   import android.widget.EditText;
   import android.widget.Toast;
    
   public class MainActivity extends Activity {
        private static final String ACTION_RECV_MSG = com.example.logindemo.action.RECEIVE_MESSAGE;
       private Button loginBtn;
       private EditText et_username;
       private EditText et_password;
       private String userName;
       private String passWord;
       private MessageReceiver receiver ;
       @Override
       protected void onCreate(Bundle savedInstanceState) {
           super.onCreate(savedInstanceState);
           setContentView(R.layout.activity_main);
           initView();
           //动态注册receiver   
           IntentFilter filter = new IntentFilter(ACTION_RECV_MSG);   
           filter.addCategory(Intent.CATEGORY_DEFAULT);   
           receiver = new MessageReceiver();   
           registerReceiver(receiver, filter);
       }
        
       private void initView() {
           // TODO Auto-generated method stub
           et_username = (EditText)findViewById(R.id.et_user);
           et_password =( EditText)findViewById(R.id.et_psw);
           loginBtn = (Button)findViewById(R.id.btn_login);
           loginBtn.setOnClickListener(new OnClickListener() {
                
               @Override
               public void onClick(View v) {
                   // TODO Auto-generated method stub
                   if(matchLoginMsg())
                   {
                       // 如果校验成功 
                       Intent msgIntent = new Intent(MainActivity.this, ConnectService.class); 
                       msgIntent.putExtra(username, et_username.getText().toString().trim()); 
                       msgIntent.putExtra(password, et_password.getText().toString().trim()); 
                       startService(msgIntent);
                   }
                    
               }
           });
       }
        
       protected boolean matchLoginMsg() {
           // TODO Auto-generated method stub
           userName = et_username.getText().toString().trim();
           passWord = et_password.getText().toString().trim();
           if(userName.equals())
           {
               Toast.makeText(MainActivity.this, 账号不能为空,Toast.LENGTH_SHORT).show();
               return false;
           }
           if(passWord.equals())
           {
               Toast.makeText(MainActivity.this, 密码不能为空,Toast.LENGTH_SHORT).show();
               return false;
           }
           return true;
       }
       //接收广播类   
       public class MessageReceiver extends BroadcastReceiver {   
           @Override   
           public void onReceive(Context context, Intent intent) {   
              String message = intent.getStringExtra(result);   
              Log.i(MessageReceiver, message); 
           // 如果登录成功 
               if (message.equals(true)){ 
                   // 启动Main Activity 
                   Intent nextIntent = new Intent(MainActivity.this, NaviActivity.class); 
                   startActivity(nextIntent); 
                   // 结束该Activity 
                   finish(); 
                   //注销广播接收器 
                   context.unregisterReceiver(this); 
               }else{ 
                   Toast.makeText(MainActivity.this, 用户名或密码错误，请重新输入!,Toast.LENGTH_SHORT).show(); 
               } 
                  
           }   
       }   
       @Override
       public boolean onCreateOptionsMenu(Menu menu) {
           // Inflate the menu; this adds items to the action bar if it is present.
           getMenuInflater().inflate(R.menu.main, menu);
           return true;
       }
    
   }

    
   
   
   

   运行截图：