Android用戶端與服務端互動_Android

本文和大家一起瞭解了一下android用戶端與服務端是怎樣互動的，具體內容如下

1.後台使用簡單的servlet，支援GET或POST。這個servlet最終返回給前台一個字串flag，值是true或false，表示登入是否成功。

servlet使用之前需要配置，主義servlet的servlet-name要和servlet-mapping的servlet-name一致，否則找不到路徑

我是在myEclipse上建立的一個web service 項目，然後部署到tomcat伺服器上以便android用戶端訪問

<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.然後我是在安卓的ADT上建立一個安卓項目，建立兩個Activity，分別作為登入介面和登入成功介面。

<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">   <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登陸樣本">   <edittext android:ems="10" android:hint="請輸入帳號" 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="請輸入密碼" 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="登陸"></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="登陸成功"> </textview></relativelayout>

 3.HTTP的訪問公用類，用於處理GET和POST請求。

 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 {  // 建立HttpClient對象  public static HttpClient httpClient = new DefaultHttpClient();  public static final String BASE_URL = http://192.168.3.14:8090/HelloWord/;   /**   *   * @param url   *      發送請求的URL   * @return 伺服器響應字串   * @throws Exception   */  public static String getRequest(String url) throws Exception {    // 建立HttpGet對象。    HttpGet get = new HttpGet(url);    // 發送GET請求    HttpResponse httpResponse = httpClient.execute(get);    // 如果伺服器成功地返迴響應    if (httpResponse.getStatusLine().getStatusCode() == 200) {      // 擷取伺服器響應字串      String result = EntityUtils.toString(httpResponse.getEntity());      return result;    } else {      Log.d(伺服器響應代碼, (new Integer(httpResponse.getStatusLine()          .getStatusCode())).toString());      return null;    }  }   /**   *   * @param url   *      發送請求的URL   * @param params   *      請求參數   * @return 伺服器響應字串   * @throws Exception   */  public static String postRequest(String url, Map<string, string=""> rawParams)      throws Exception {    // 建立HttpPost對象。    HttpPost post = new HttpPost(url);    // 如果傳遞參數個數比較多的話可以對傳遞的參數進行封裝    List<namevaluepair> params = new ArrayList<namevaluepair>();    for (String key : rawParams.keySet()) {      // 封裝請求參數      params.add(new BasicNameValuePair(key, rawParams.get(key)));    }    // 佈建要求參數    post.setEntity(new UrlEncodedFormEntity(params, UTF-8));    // 發送POST請求    HttpResponse httpResponse = httpClient.execute(post);    // 如果伺服器成功地返迴響應    if (httpResponse.getStatusLine().getStatusCode() == 200) {      // 擷取伺服器響應字串      String result = EntityUtils.toString(httpResponse.getEntity());      return result;    }    return null;  }}</namevaluepair></namevaluepair></string,>

4.IntentService服務，用於在後台以隊列方式處理耗時操作。

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    /**     * 經測試，IntentService裡面是可以進行耗時的操作的      * IntentService使用隊列的方式將請求的Intent排入佇列，     * 然後開啟一個worker thread(線程)來處理隊列中的Intent      * 對於非同步startService請求，IntentService會處理完成一個之後再處理第二個      */     Boolean flag = false;     //通過intent擷取主線程傳來的使用者名稱和密碼字串     String username = intent.getStringExtra(username);     String password = intent.getStringExtra(password);     flag = doLogin(username, password);     Log.d(登入結果, flag.toString());           Intent broadcastIntent = new Intent();     broadcastIntent.setAction(ACTION_RECV_MSG);      broadcastIntent.addCategory(Intent.CATEGORY_DEFAULT);      broadcastIntent.putExtra(result, flag.toString());     sendBroadcast(broadcastIntent);    }      // 定義發送請求的方法   private Boolean doLogin(String username, String password)   {     String strFlag = ;     // 使用Map封裝請求參數     HashMap<string, string=""> map = new HashMap<string, string="">();     map.put(un, username);     map.put(pw, password);     // 定義發送請求的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 {       // 發送請求       strFlag = HttpUtil.postRequest(url, map); //POST方式 //     strFlag = HttpUtil.getRequest(url); //GET方式       Log.d(伺服器傳回值, 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中註冊IntentService。注意uses-permission節點，為程式開啟訪問網路的許可權。 

<!--?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.登陸介面處理，注意

按鈕監聽事件中，使用Intent將要傳遞的值傳給service。接收廣播類中，同樣使用Intent將要傳遞的值傳給下一個Activity。在onCreate()中，動態註冊接收廣播類的執行個體receiver。在接收廣播類中，不要使用完畢後忘記登出接收器，否則會報一個Are you missing a call to unregisterReceiver()? 的異常。 

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();    //動態註冊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())        {          // 如果校正成功           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, 帳號不可為空,Toast.LENGTH_SHORT).show();      return false;    }    if(passWord.equals())    {      Toast.makeText(MainActivity.this, 密碼不可為空,Toast.LENGTH_SHORT).show();      return false;    }    return true;  }  //接收廣播類    public class MessageReceiver extends BroadcastReceiver {      @Override      public void onReceive(Context context, Intent intent) {        String message = intent.getStringExtra(result);        Log.i(MessageReceiver, message);     // 如果登入成功       if (message.equals(true)){         // 啟動Main Activity         Intent nextIntent = new Intent(MainActivity.this, NaviActivity.class);         startActivity(nextIntent);         // 結束該Activity         finish();         //登出廣播接收器         context.unregisterReceiver(this);       }else{         Toast.makeText(MainActivity.this, 使用者名稱或密碼錯誤，請重新輸入!,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;  } }

以上就是本文的全部內容，希望對大家的學習有所協助。