Background Processes

For many apps, background processes are needed to accomplish some tasks.

Here, I will setup a class that runs a background process.

To set up the file in Eclipse, navigate to the package you want to add this to, and right click on src->"package_name", where package_name is something like com.example.project_name.  From there, select New->Class.  In the popup:
I set the name of my class to "Service_handler".
I set the superclass to "Service".
I then added some methods, so that the basic framework looks like this:

public class Service_handler extends Service 
{ 
    public IBinder onBind(Intent intent) 
    {
        return null;
    }

    public void onCreate() 
    {
        System.out.println("onCreate");
    }
    
    public void onDestroy() 
    {
        System.out.println("onDestroy");
    }

    public void onStart(Intent intent, int startid) 
    {
        // Grab a "log_msg" from the caller
        String message = intent.getStringExtra("log_msg");
        System.out.println("onStart "+message);
    }
}

Also, add this to the xml manifest file, within the application tags.
<service android:enabled="true" android:name=".Service_handler" >

Now you start the service with code added to your main activity, like this:

public void onCreate(Bundle savedInstanceState) 
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_my_first);

    Intent myIntent = new Intent(getApplicationContext(), 
                                 Service_handler.class);
    myIntent.putExtra("log_msg", "hello_from_activity");
    startService(myIntent);
}

If you used the code above you should see this text in the logCat output, "onStart hello_from_activity".