Exception when I run my application from Eclipse

Question

I've been having this problem for almost 2 months now and can't figure it out. The problem is that if my application is running and I run (reinstall) my application from Eclipse, I get an error message indicating that my application has crashed 'Unfortunately, has stopped.'. I notice that it also occurs when I run it away from my PC/Eclipse, I think that it happens only after I don't run it for a while.

It only occurs if the app is active in the 3rd activity (BaseDiagramActivity) and then I run the app again from Eclipse. I've stripped out basically all the application except the 3 activities and It's still happening.

I've searched and searched for a solution to this problem but can't find any good answer or one that applies to me.

It doesn't seem like a hardware or android version issue as I'm running this on my tablet (4.0.3) and my phone (4.0.2, was happening on 4.0.1 before update). Unless of course it is an ice cream sandwich bug.

Let me know if any more info is required.

The exception (Tag=AndroidRuntime)

FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to instantiate application android.app.Application: java.lang.NullPointerException
   at android.app.LoadedApk.makeApplication(LoadedApk.java:482)
   at android.app.ActivityThread.handleBindApplication(ActivityThread.java:3938)
   at android.app.ActivityThread.access$1300(ActivityThread.java:123)
   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1185)
   at android.os.Handler.dispatchMessage(Handler.java:99)
   at android.os.Looper.loop(Looper.java:137)
   at android.app.ActivityThread.main(ActivityThread.java:4424)
   at java.lang.reflect.Method.invokeNative(Native Method)
   at java.lang.reflect.Method.invoke(Method.java:511)
   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
   at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
   at android.app.LoadedApk.initializeJavaContextClassLoader(LoadedApk.java:362)
   at android.app.LoadedApk.getClassLoader(LoadedApk.java:305)
   at android.app.LoadedApk.makeApplication(LoadedApk.java:474)
   ... 11 more

The Android Code

LoadedApk.initializeJavaContextClassLoader() - Line 362 seems to be the offender

Below are the relevant files:

AndroidManifest.xml

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

    <uses-sdk android:minSdkVersion="14" />

    <application 
        android:icon="@drawable/ic_launcher" 
        android:label="@string/app_name" >
        <activity 
            android:name="HomeActivity" 
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name="LoadDiagramActivity" android:label="Load Diagram"></activity>
        <activity android:name="BaseDiagramActivity" android:label="Base Diagram"></activity>
    </application>

</manifest>

HomeActivity.java

public class HomeActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        setContentView(R.layout.home);

        Button diagramButton = (Button)findViewById(R.id.diagram);
        diagramButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                startActivity(new Intent(HomeActivity.this, LoadDiagramActivity.class));
            }
        });
    }
}

LoadDiagramActivity.java

public class LoadDiagramActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        ActionBar actionBar = getActionBar();
        actionBar.setDisplayHomeAsUpEnabled(true);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater menuInflater = getMenuInflater();
        menuInflater.inflate(R.menu.load_diagram_menu, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case android.R.id.home:
                finish();
                return true;
            case R.id.add_new_diagram:
                startActivity(new Intent(this, BaseDiagramActivity.class));
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }
}

BaseDiagramActivity.java

it doesn't actually matter what activity this is, the exception occurs as long as a 'third' activity is started (or clicking the add button on LoadDiagramActivity.

public class BaseDiagramActivity extends Activity {
}

home.xml

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

    <Button
        android:id="@+id/diagram"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Diagram" />

</LinearLayout>

Additional information

When I stripped down my project in order to ask a simpler answer, I moved everything into the package's namespace. In the actual project there are 5 namespaces, they were still present when I was testing with the stripped down version however just not called (as far as I could see).

Here are the packages:

• [package] - general logic
• [package].activities - all activities and base activities
• [package].database - all interaction with the database
• [package].models - models for saving/loading data
• [package].renderables - objects drawn to a canvas

I have tried to add an `android:sharedUserId' attribute to the manifest and and it seemed to do nothing both times I tried. When I was initially investigating this I came to the conclusion that the shared user id only applied to different projects, not different packages.

Also I don't believe there was any interaction with the database when I stripped everything down. The fact that the 3rd activity could be any activity, even HomeActivity, was something against this theory.

Useful links

• stackoverflow: android.app.Application cannot be instantiated due to NullPointerException
• GreoCode android.app.LoadedApk on 4.0.1
• Possible race condition?
• Android issue #25869

Update 1/11/2012

Last couple of days I've jumped back into this project, I created a brand new project in Eclipse Juno (was on Helios before) and transferred everything over manually so that Eclipse and Android tools handled almost all of the Manifest interaction but it's still occurring. I will look at it a bit more over the next few days and update if I find anything.

FYI my new project is targeting the following:

<uses-sdk
    android:minSdkVersion="14"
    android:targetSdkVersion="15" />

The new project structure also has all the activities in the root package now (ie. [package], not [package].activities). I'm also using the (new?) syntax to show the parent activity:

<meta-data
    android:name="android.support.PARENT_ACTIVITY"
    android:value="[my package].LoadDiagramActivity" />

It is also still occurring on my now updated Galaxy Nexus running Jellybean 4.1.2.

Answer 1

Try adding one more thing in Manifest file, I am sure you have already tried..

<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
    package="[my package]" 
    android:versionCode="1" 
    android:versionName="1.0"
    android:sharedUserId="com.mj.app" > 

It seems like in your project you have multiple PACKAGES, like com.package.p1 , com.package.p2 ,com.package.p3..

And while starting you are in p1 and then moves on to p2 - p3... and at that time you try to run it again..so the Android gives you error.