Can't start a service from an Activity

Question

I'm working on my Android app and I'm having a bit of a weird problem. I'm trying to run a service from the main activity and with no luck. No matter what I tries no log messages appears. I found out that when erase the service statement out of the manifest I get the "not found" message, but when return it - nada, the log is empty tough I try to print.

I must say that I've tried to look for the answer for weeks and read a bunch of solution to some similar problems but again with no luck on that matter.

In the activity I do this:

startService (new Intent (this, GpsCompassService.class));

and in the service I do:

public class GpsCompassService extends ManagerService{ 
    
    private static final String TAG = "GpsCompassServiceActivity";

    public void onCreate(Bundle savedInstanceState) {
        Log.i("GpsCompassService onCreate", null);      
    }
    //------------------------------------------------------------
    public void onResume(){
        Log.i("GpsCompassService has launched", null);;
}

the manifst.xml:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="project.main.app"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk android:minSdkVersion="10" />
    <uses-permission android:name="android.permission.INTERNET"/>
    <uses-permission android:name="android.permission.CAMERA" />
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
    
    <application android:name=".ManagerApplication" android:icon="@drawable/icon" android:label="@string/app_name" >
        <activity android:label="@string/app_name" android:name=".MenuActivity" >
            <intent-filter >
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:label="@string/app_name"  android:name="project.main.app.CameraPreviewActivity" >
            <intent-filter >
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.DEFAULT" />
            </intent-filter>
        </activity>
         <service android:enabled="true" android:name="project.main.app.GpsCompassService"> 
             <intent-filter> 
                 <action android:name="project.main.app.GpsCompassService"></action> 
             </intent-filter> 
         </service>
    </application>

</manifest>

What am I doing wrong?

package project.main.app;

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

public class ManagerService extends Service {

    public ManagerApplication getManagerApp(){
        ManagerApplication appSharedDate = (ManagerApplication)getApplication();
        return appSharedDate;
    }

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

Here is the logcat file:

01-07 20:19:29.281: E/AndroidRuntime(557): FATAL EXCEPTION: main
01-07 20:19:29.281: E/AndroidRuntime(557): java.lang.RuntimeException: Unable to create service project.main.app.GpsCompassService: java.lang.NullPointerException: println needs a message
01-07 20:19:29.281: E/AndroidRuntime(557):  at android.app.ActivityThread.handleCreateService(ActivityThread.java:1955)
01-07 20:19:29.281: E/AndroidRuntime(557):  at android.app.ActivityThread.access$2500(ActivityThread.java:117)
01-07 20:19:29.281: E/AndroidRuntime(557):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:985)
01-07 20:19:29.281: E/AndroidRuntime(557):  at android.os.Handler.dispatchMessage(Handler.java:99)
01-07 20:19:29.281: E/AndroidRuntime(557):  at android.os.Looper.loop(Looper.java:130)
01-07 20:19:29.281: E/AndroidRuntime(557):  at android.app.ActivityThread.main(ActivityThread.java:3683)
01-07 20:19:29.281: E/AndroidRuntime(557):  at java.lang.reflect.Method.invokeNative(Native Method)
01-07 20:19:29.281: E/AndroidRuntime(557):  at java.lang.reflect.Method.invoke(Method.java:507)
01-07 20:19:29.281: E/AndroidRuntime(557):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
01-07 20:19:29.281: E/AndroidRuntime(557):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
01-07 20:19:29.281: E/AndroidRuntime(557):  at dalvik.system.NativeStart.main(Native Method)
01-07 20:19:29.281: E/AndroidRuntime(557): Caused by: java.lang.NullPointerException: println needs a message
01-07 20:19:29.281: E/AndroidRuntime(557):  at android.util.Log.println_native(Native Method)
01-07 20:19:29.281: E/AndroidRuntime(557):  at android.util.Log.i(Log.java:158)
01-07 20:19:29.281: E/AndroidRuntime(557):  at project.main.app.GpsCompassService.onCreate(GpsCompassService.java:32)
01-07 20:19:29.281: E/AndroidRuntime(557):  at android.app.ActivityThread.handleCreateService(ActivityThread.java:1945)

Answer 1

Assuming ManagerService extends Service then neither of the following methods are valid for a Service and will never be called...

public void onCreate(Bundle savedInstanceState) {
    Log.i("GpsCompassService onCreate", null);      
}
//------------------------------------------------------------
public void onResume(){
    Log.i("GpsCompassService has launched", null);;

The onCreate() method of Service doesn't take any parameters and onResume() simply isn't a Service method.

Delete onResume() and change your onCreate() code to something like...

@Override
public void onCreate() {
    Log.i("GpsCompassService", "onCreate()");      
}

EDIT: Also, don't use null for the second (message) parameter when using Log.

Answer 2

Like MisterSquonk said, remove your onResume() method and change your onCreate() method.

Then change the line

public class GpsCompassService extends ManagerService{ 

to

public class GpsCompassService extends Service{ 

The content of your ManagerService declaration can be easily implemented into the Service's onCreate() method or into a method like

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
    super.onStart(intent, startId);
    doSomething();
    return START_NOT_STICKY; // or START_STICKY, depending on your needs
}

Also change the lines

Log.i("GpsCompassService onCreate", null);    

to

Log.i("GpsCompassService onCreate", "some message");    

Otherwise the app will crash, as the second parameter must not be null.