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：