Android Service Binding, Thread handling

안드로이드의 Service 에서 실행되는 Thread를 Activity에서 제어하는 예

액티비티에서 서비스를 바인딩하는 방법을 이용하면 액티비티가 서비스의 참조를 가진 상태에서 서비스를 직접 제어할 수 있게 된다

servicebind.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="onBtnStart"
        android:text="Start thread within Service" />

    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="onBtnStop"
        android:text="Stop thread within Service" />

</LinearLayout>

LocalService.java

package com.example.androidapp;

import java.util.Date;
import java.util.Random;

import android.app.Service;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;
import android.util.Log;

public class LocalService extends Service {
    // Binder given to clients
    private final IBinder mBinder = new LocalBinder();
    public boolean go = false;

    public class LocalBinder extends Binder {
        LocalService getService() {  // Activity에서 호출하면 서비스 클래스의 인스턴스를 리턴함
            // Return this instance of LocalService so clients can call public methods
            return LocalService.this;
        }
    }

    @Override
    public IBinder onBind(Intent intent) {
        return mBinder;
    }

    public void startThread() {
    	go = true;
		new Thread() {
			@Override
			public void run() {
				while(go) {
					Date date = new Date();
					Log.i("오늘날짜", date.toString());
					try {
						Thread.sleep(1000);
					} catch (InterruptedException e) {
						e.printStackTrace();
					}
				}
			}
		}.start();
    }
    
    public void stopThread() {
    	go = false;
    }
}

ServiceBindingActivity.java

package com.example.androidapp;

import com.example.androidapp.LocalService.LocalBinder;

import android.app.Activity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.util.Log;
import android.view.View;
import android.widget.Toast;

public class ServiceBindingActivity extends Activity {
    LocalService mService;
    boolean mBound = false;

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

    @Override
    protected void onStart() {
        super.onStart();
        // Bind to LocalService
        Intent intent = new Intent(this, LocalService.class);
        bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
    }

    @Override
    protected void onStop() {
        super.onStop();
        // Unbind from the service
        if (mBound) {
            mService.stopThread();
            unbindService(mConnection);
            mBound = false;
        }
    }

    /** Called when a button is clicked (the button in the layout file attaches to
      * this method with the android:onClick attribute) */
    public void onBtnStart(View v) {
        if (mBound) {
            // Call a method from the LocalService.
            // However, if this call were something that might hang, then this request should
            // occur in a separate thread to avoid slowing down the activity performance.
            mService.startThread();
        }
    }
    
    public void onBtnStop(View v) {
    	if(mBound) {
    		mService.stopThread();
    	}
    }

    /** Defines callbacks for service binding, passed to bindService() */
    private ServiceConnection mConnection = new ServiceConnection() {
        // 아래의 두번째 파라미터에는 Service측의 onBind()에서 리턴한 IBinder 객체가 전달됨
        public void onServiceConnected(ComponentName className,IBinder binder) {
            // We've bound to LocalService, cast the IBinder and get LocalService instance
            LocalBinder localBinder = (LocalBinder) binder;
            mService = localBinder.getService();
            mBound = true;
            Log.i("service 상태", "서비스 연결됨");
        }

        public void onServiceDisconnected(ComponentName arg0) {
            mBound = false;
            Log.i("service 상태", "서비스 연결해제됨");
        }
    };
}