IntentService を使ってみる：android

http://developer.android.com/guide/components/services.html で紹介されているソースコードを実行してみる。
サービスの終了操作を気にしないでいいようです。
５秒後にサービス終了するコード。

package com.example.intentservice;

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

public class MainActivity extends Activity {

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);

  Intent intent = new Intent(this, HelloIntentService.class);
  startService(intent);
 }
}

package com.example.intentservice;

import android.app.IntentService;
import android.content.Intent;
import android.util.Log;

public class HelloIntentService extends IntentService {

 private static final String TAG = "HelloIntentService";

 /** 
  * A constructor is required, and must call the super IntentService(String)
  * constructor with a name for the worker thread.
  */
 public HelloIntentService() {
  super("HelloIntentService");

  Log.v(TAG, "HelloIntentService");
 }

 /**
  * The IntentService calls this method from the default worker thread with
  * the intent that started the service. When this method returns, IntentService
  * stops the service, as appropriate.
  */
 @Override
 protected void onHandleIntent(Intent intent) {
  Log.v(TAG, "onHandleIntent");

  // Normally we would do some work here, like download a file.
  // For our sample, we just sleep for 5 seconds.
  long endTime = System.currentTimeMillis() + 5 * 1000;
  while (System.currentTimeMillis() < endTime) {
   synchronized (this) {
    try {
     wait(endTime - System.currentTimeMillis());
    } catch (Exception e) {
    }
   }
  }
  Log.v(TAG, "onHandleIntent 終了");
 }

 @Override
 public void onDestroy() {
  Log.v(TAG, "onDestroy");
 }

}

---

UIの変更を考えてみる

package com.example.intentservice;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.os.Messenger;
import android.widget.TextView;

public class MainActivity extends Activity {

 public static class SampleHandler extends Handler {
  private MainActivity con;

  public SampleHandler(MainActivity mainActivity) {
   // TODO 自動生成されたコンストラクター・スタブ
   this.con = mainActivity;
  }

  @Override
  public void handleMessage(Message msg) {
   Bundle bundle = msg.getData();
   
    TextView textView = (TextView) con.findViewById(R.id.textView1);
    textView.setText( bundle.getString("mystring") );
  }
 }

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  
  SampleHandler handler = new SampleHandler(this);

  Intent intent = new Intent(this, HelloIntentService.class);
  intent.putExtra("messenger", new Messenger(handler));
  startService(intent);
 }
}

package com.example.intentservice;

import android.app.IntentService;
import android.content.Intent;
import android.os.Bundle;
import android.os.Message;
import android.os.Messenger;
import android.os.RemoteException;
import android.util.Log;

public class HelloIntentService extends IntentService {

 private static final String TAG = "HelloIntentService";

 public HelloIntentService() {
  super("HelloIntentService");

  Log.v(TAG, "HelloIntentService");
 }

 @Override
 protected void onHandleIntent(Intent intent) {
  Log.v(TAG, "onHandleIntent");

  Bundle bundle = intent.getExtras();
  if (bundle != null) {
   Messenger messenger = (Messenger) bundle.get("messenger");
   Message msg = Message.obtain();
   
   Bundle data = new Bundle();
   data.putString("mystring", "Hello!");
   msg.setData(data);
   try {
    messenger.send(msg);
   } catch (RemoteException e) {
    Log.i("error", "error");
   }
  }
 }

 @Override
 public void onDestroy() {
  Log.v(TAG, "onDestroy");
 }

}

---

while ループが永遠に終わらない処理の場合、
呼び出し元のアクティビティーが終了しても、動き続けるので、
IntentServiceを終了させる処理が必要なようです。

package com.example.intentservice;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.os.Messenger;
import android.widget.TextView;

public class MainActivity extends Activity {

 public static class SampleHandler extends Handler {
  private MainActivity con;

  public SampleHandler(MainActivity mainActivity) {
   // TODO 自動生成されたコンストラクター・スタブ
   this.con = mainActivity;
  }

  @Override
  public void handleMessage(Message msg) {
   Bundle bundle = msg.getData();

   TextView textView = (TextView) con.findViewById(R.id.textView1);
   textView.setText(bundle.getString("mystring"));
  }
 }

 private SampleHandler handler;
 private Intent intent;

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);

  handler = new SampleHandler(this);

  intent = new Intent(this, HelloIntentService.class);
  intent.putExtra("messenger", new Messenger(handler));
  startService(intent);
 }

 @Override
 public void onDestroy() {
  super.onDestroy();
  // The service is no longer used and is being destroyed

  if (intent != null) {
   stopService(intent);
   intent = null;
  }
 }
}

package com.example.intentservice;

import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.TimeZone;

import android.app.IntentService;
import android.content.Intent;
import android.os.Bundle;
import android.os.Message;
import android.os.Messenger;
import android.os.RemoteException;
import android.util.Log;

public class HelloIntentService extends IntentService {

 private static final String TAG = "HelloIntentService";
 private boolean loopFlag = true;

 public HelloIntentService() {
  super("HelloIntentService");

  Log.v(TAG, "HelloIntentService");

 }

 @Override
 protected void onHandleIntent(Intent intent) {
  Log.v(TAG, "onHandleIntent");

  Bundle bundle = intent.getExtras();

  while (loopFlag) {
   synchronized (this) {
    try {
     Log.v(TAG, "HelloIntentService");
     GregorianCalendar gc = (GregorianCalendar) GregorianCalendar.getInstance(TimeZone.getTimeZone("Asia/Tokyo"));
     String stringTime = gc.get(Calendar.HOUR_OF_DAY) + ":" + gc.get(Calendar.MINUTE) + ":" + gc.get(Calendar.SECOND);

     if (bundle != null) {
      Messenger messenger = (Messenger) bundle.get("messenger");
      Message msg = Message.obtain();

      Bundle data = new Bundle();

      data.putString("mystring", stringTime);
      msg.setData(data);
      try {
       messenger.send(msg);
      } catch (RemoteException e) {
       Log.i("error", "error");
      }
     }

     wait(1000);
    } catch (Exception e) {
    }
   }
  }

 }

 @Override
 public void onDestroy() {
  Log.v(TAG, "onDestroy");
  loopFlag = false;
 }

}