Android啓動服務的一個方面

Question

我試圖啓動一個方面的android服務。我的項目是basicly執行以下操作：

• 簡單的活動了）和
• 在我Test.aj看點稱爲callMethodA（一個方法，我想之前開始我senderServicecallMethodA（）調用。

但是，每次嘗試啓動服務時，都會引發InvocationTargetException。顯然，我的問題是在我的方面，因爲老實說，我不知道如何開始一個方面的服務。

這裏是我的Sender1Activity.java

package com.example.sender; 

    import android.app.Activity; 
    import android.content.Intent; 
    import android.os.Bundle; 
    import android.view.Menu; 
    import android.view.View; 
    import android.widget.Button; 

    public class Sender1Activity extends Activity { 
     Button btn_send; 
     Intent serviceIntent; 

     @Override 
     public void onCreate(Bundle savedInstanceState) { 
      super.onCreate(savedInstanceState); 

      setContentView(R.layout.activity_sender1); 
      btn_send = (Button) findViewById(R.id.buttonSend); 
     } 


     public void callMethodA(View v){ 

      System.out.println("Method A called"); 
     } 

     @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; 
     } 

    } 

和這裏的senderService.java：

package com.example.sender; 

import java.util.Random; 

import android.app.Service; 
import android.content.Intent; 
import android.os.Handler; 
import android.os.IBinder; 

public class senderService extends Service { 

    String value = String.valueOf("a"); 


    @Override 
    public void onCreate() { 
     super.onCreate(); 

    } 

    public int onStartCommand(Intent intent, int flags, int startId) { 



     mSendValue.removeCallbacks(hMyValueTask); 
     mSendValue.post(hMyValueTask); 
     return startId; 
    } 

    public Handler mSendValue = new Handler(); 
    public Runnable hMyValueTask = new Runnable() { 
     public void run() { 
      int n = new Random().nextInt(3000); 
      System.out.println("A random delay : " + n); 
      publishBuiltinAccelResults(value); 
      mSendValue.postDelayed(hMyValueTask, (long) n); 

     } 
    }; 

    @Override 
    public void onDestroy() { 

    } 

    public void publishBuiltinAccelResults(String value) { 

     Intent intent = new Intent("ResultsA"); 
     intent.putExtra("resultA", value); 
     sendBroadcast(intent); 
    } 



    @Override 
    public IBinder onBind(Intent intent) { 
     // TODO Auto-generated method stub 
     return null; 
    } 

} 

最後，這裏的Test.aj看點代碼：

package com.example.sender; 

import android.app.Activity; 
import android.content.Intent; 
import android.os.Bundle; 

public aspect Test extends Activity { 
    int i = 1; 

    protected void onCreate(Bundle savedInstanceState) { 

    }; 

    pointcut pointcutCatchMethod() : execution(* callMethodA(*)) 
    && within(com.example.sender.Sender1Activity); 

    before() : pointcutCatchMethod() { 
     Intent sendIntent = new Intent(this, senderService.class); 
     startService(sendIntent); 

     System.out.println(" sendBroadcast cought by Aspect , aspect No: " + i); 

    } 

} 

logcat的：

03-07 15:20:27.015: E/AndroidRuntime(6714): FATAL EXCEPTION: main 
03-07 15:20:27.015: E/AndroidRuntime(6714): java.lang.IllegalStateException: Could not execute method of the activity 
03-07 15:20:27.015: E/AndroidRuntime(6714):  at android.view.View$1.onClick(View.java:3660) 
03-07 15:20:27.015: E/AndroidRuntime(6714):  at android.view.View.performClick(View.java:4162) 
03-07 15:20:27.015: E/AndroidRuntime(6714):  at android.view.View$PerformClick.run(View.java:17082) 
03-07 15:20:27.015: E/AndroidRuntime(6714):  at android.os.Handler.handleCallback(Handler.java:615) 
03-07 15:20:27.015: E/AndroidRuntime(6714):  at android.os.Handler.dispatchMessage(Handler.java:92) 
03-07 15:20:27.015: E/AndroidRuntime(6714):  at android.os.Looper.loop(Looper.java:137) 
03-07 15:20:27.015: E/AndroidRuntime(6714):  at android.app.ActivityThread.main(ActivityThread.java:4867) 
03-07 15:20:27.015: E/AndroidRuntime(6714):  at java.lang.reflect.Method.invokeNative(Native Method) 
03-07 15:20:27.015: E/AndroidRuntime(6714):  at java.lang.reflect.Method.invoke(Method.java:511) 
03-07 15:20:27.015: E/AndroidRuntime(6714):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1007) 
03-07 15:20:27.015: E/AndroidRuntime(6714):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:774) 
03-07 15:20:27.015: E/AndroidRuntime(6714):  at dalvik.system.NativeStart.main(Native Method) 
03-07 15:20:27.015: E/AndroidRuntime(6714): Caused by: java.lang.reflect.InvocationTargetException 
03-07 15:20:27.015: E/AndroidRuntime(6714):  at java.lang.reflect.Method.invokeNative(Native Method) 
03-07 15:20:27.015: E/AndroidRuntime(6714):  at java.lang.reflect.Method.invoke(Method.java:511) 
03-07 15:20:27.015: E/AndroidRuntime(6714):  at android.view.View$1.onClick(View.java:3655) 
03-07 15:20:27.015: E/AndroidRuntime(6714):  ... 11 more 
03-07 15:20:27.015: E/AndroidRuntime(6714): Caused by: java.lang.NullPointerException 
03-07 15:20:27.015: E/AndroidRuntime(6714):  at android.content.ContextWrapper.startService(ContextWrapper.java:390) 
03-07 15:20:27.015: E/AndroidRuntime(6714):  at com.example.sender.Test.ajc$before$com_example_sender_Test$1$61afa7eb(Test.aj:23) 
03-07 15:20:27.015: E/AndroidRuntime(6714):  at com.example.sender.Sender1Activity.callMethodA(Sender1Activity.java:25) 
03-07 15:20:27.015: E/AndroidRuntime(6714):  ... 14 more 

Answer 1

一個活動需要是由android編輯的new。你在這個項目中有兩個活動，但只有主要的是由android編輯的new。第二個（方面）不是。

我會捕獲切入點中的目標（Sender1Activity），並在那裏創建一個方法來啓動一個服務，因爲這是唯一具有有效上下文的Activity。

Answer 2

我已經解決了這個問題，現在，多虧了aepurniet，這裏的解決方案，在該方面，切入點應該是：

public aspect Test extends Activity{ 
    int i = 1; 



    pointcut pointcutCatchMethod(Activity activity) : execution(* callMethodA(*)) 
    && target(activity); 


    before(Activity activity) : pointcutCatchMethod(activity) { 

     Intent sendIntent = new Intent(activity.getApplicationContext(),senderService.class); 

     activity.startService(sendIntent); 

     System.out.println(" sendBroadcast cought by Aspect , aspect No: " + i); 

    } 




}