Android Background Service Example

In this example we are going to learn about Android Service. The Android Service is one of the most important components and building blocks in an Android System. One obvious characteristic of the Service component is that it offers no UI. It’s simply a program that runs on the background as log as it is required.

It is important to notice that Services are either Threads nor processes or Activities.  You should use Android Services when you have to perform a time consuming and long task, like loading an Image, or a File, or download something for the Internet and asynchronous tasks in general. Using a Service you can let the UI Thread handle only UI tasks.

1) main.xml

<RelativeLayout xmlns:android=”http://schemas.android.com/apk/res/android”
xmlns:tools=”http://schemas.android.com/tools”
android:layout_width=”match_parent”
android:layout_height=”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” >

<Button
android:id=”@+id/button2″
android:layout_width=”wrap_content”
android:layout_height=”wrap_content”
android:layout_alignBaseline=”@+id/button1″
android:layout_alignBottom=”@+id/button1″
android:layout_alignParentRight=”true”
android:onClick=”stopNewService”
android:text=”Stop Service” />

<Button
android:id=”@+id/button1″
android:layout_width=”wrap_content”
android:layout_height=”wrap_content”
android:layout_alignParentLeft=”true”
android:layout_alignParentTop=”true”
android:layout_marginTop=”23dp”
android:onClick=”startNewService”
android:text=”Start Service” />

</RelativeLayout>

 

2) MyService.java

package com.w2class.android.androidserviceexample;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.widget.Toast;

public class MyService extends Service {
public MyService() {
}

@Override
public IBinder onBind(Intent intent) {
// TODO: Return the communication channel to the service.
throw new UnsupportedOperationException(“Not yet implemented”);
}

@Override
public void onCreate() {
Toast.makeText(this, “The new Service was Created”, Toast.LENGTH_LONG).show();

}

@Override
public void onStart(Intent intent, int startId) {
// For time consuming an long tasks you can launch a new thread here…
Toast.makeText(this, ” Service Started”, Toast.LENGTH_LONG).show();

}

@Override
public void onDestroy() {
Toast.makeText(this, “Service Destroyed”, Toast.LENGTH_LONG).show();

}
}

3) MainActivity.java

package com.w2class.android.androidserviceexample;

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

public class MainActivity extends Activity {

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

// Start the  service
public void startNewService(View view) {

startService(new Intent(this, MyService.class));
}

// Stop the  service
public void stopNewService(View view) {

stopService(new Intent(this, MyService.class));
}

@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;
}
}

4) Run the application