Android java app works on one version but not the next

Question

I'm very new to android, in fact only started yesterday. I managed to get an application setup with tabs. It works fine on a 2.2 virtual avd (i think it is called). But the version my HTC has is 2.0.1 I'm posting snippets of the code below as well as debug info.

Logcat shows the following error

08-02 09:56:05.946: WARN/dalvikvm(414): threadid=3: thread exiting with uncaught exception (group=0x4001b188)
08-02 09:56:05.956: ERROR/AndroidRuntime(414): Uncaught handler: thread main exiting due to uncaught exception
08-02 09:56:06.196: ERROR/AndroidRuntime(414): java.lang.RuntimeException: Unable to start activity ComponentInfo{org.hyperActiveSolutions/org.hyperActiveSolutions.Organizer}: java.lang.NullPointerException
08-02 09:56:06.196: ERROR/AndroidRuntime(414):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2481)
08-02 09:56:06.196: ERROR/AndroidRuntime(414):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2497)

There is more to that but i thought this was the relevant bit, the rest is just the long stack trace.

My android manifest file looks like this

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
      package="org.hyperActiveSolutions"
      android:versionCode="1"
      android:versionName="1.0">
    <application android:icon="@drawable/icon" android:label="@string/app_name">
        <activity android:label="@string/app_name"
                  android:theme="@android:style/Theme.NoTitleBar" android:name="Organizer">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

    <activity android:name="Home" ></activity>
<activity android:name="Account"></activity>
<activity android:name="Agenda" ></activity>
<activity android:name="Lists" ></activity>
</application>

<uses-sdk android:minSdkVersion="6" android:targetSdkVersion="6"></uses-sdk>
</manifest> 

As you can see the minimum sdk and the target have been set to my phone's version. This is the start of my entry class. Below where this snippet ends is 3 other tabs being added in exactly the same way as Home.

public class Organizer extends TabActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);     
        this.setContentView(R.layout.main);
        final TabHost tabHost = getTabHost();  // The activity TabHost

   // Create an Intent to launch an Activity for the tab (to be reused)


   // Initialize a TabSpec for each tab and add it to the TabHost
   tabHost.addTab(tabHost.newTabSpec("home").setIndicator("Home",
            getResources().getDrawable(R.drawable.home)).setContent(new Intent().setClass(this, Home.class)));

All my resources exists including the classes i'm instantiating with each tab. The only other thing i can think of that might be relevant is my main.xml for the layout. It was copied from the android dev site, in one of the tutorials.

<?xml version="1.0" encoding="utf-8"?>
<TabHost xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@android:id/tabhost"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent">
        <TabWidget
            android:id="@android:id/tabs"
            android:layout_width="fill_parent"
            android:layout_height="wrap_content" />
        <FrameLayout
            android:id="@android:id/tabcontent"
            android:layout_width="fill_parent"
            android:layout_height="fill_parent" />
    </LinearLayout>
</TabHost>

As i said it works fine on version 2.2 but dies on 2.0.1 and the message displayed on screen is just "Organizer termintated unexpectedly"....part of the message anyway.

So can anyone spot anything i have that would make it not compatible with the 2.0.1 SDK.

thanks in advance

full stack trace

08-02 11:47:54.006: WARN/dalvikvm(2588): threadid=3: thread exiting with uncaught exception (group=0x4001b188)
08-02 11:47:54.016: ERROR/AndroidRuntime(2588): Uncaught handler: thread main exiting due to uncaught exception
08-02 11:47:54.256: ERROR/AndroidRuntime(2588): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.organizer/com.organizer.Organizer}: java.lang.NullPointerException
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2481)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2497)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.app.ActivityThread.access$2200(ActivityThread.java:119)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1848)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.os.Handler.dispatchMessage(Handler.java:99)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.os.Looper.loop(Looper.java:123)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.app.ActivityThread.main(ActivityThread.java:4338)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at java.lang.reflect.Method.invokeNative(Native Method)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at java.lang.reflect.Method.invoke(Method.java:521)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at dalvik.system.NativeStart.main(Native Method)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588): Caused by: java.lang.NullPointerException
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.widget.TabWidget.onFocusChange(TabWidget.java:351)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.view.View.onFocusChanged(View.java:2622)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.view.View.handleFocusGainInternal(View.java:2445)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.view.ViewGroup.handleFocusGainInternal(ViewGroup.java:403)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.view.View.requestFocus(View.java:3562)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.view.ViewGroup.requestFocus(ViewGroup.java:975)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:1020)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.view.ViewGroup.requestFocus(ViewGroup.java:976)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:1020)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.view.ViewGroup.requestFocus(ViewGroup.java:979)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:1020)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.view.ViewGroup.requestFocus(ViewGroup.java:976)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:1020)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.view.ViewGroup.requestFocus(ViewGroup.java:979)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.view.View.requestFocus(View.java:3513)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.view.View.requestFocus(View.java:3491)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.widget.TabHost.setCurrentTab(TabHost.java:334)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.widget.TabHost.addTab(TabHost.java:213)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at com.organizer.Organizer.onCreate(Organizer.java:25)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2444)
08-02 11:47:54.256: ERROR/AndroidRuntime(2588):     ... 11 more
08-02 11:47:54.476: INFO/Process(62): Sending signal. PID: 2588 SIG: 3
08-02 11:47:54.476: INFO/dalvikvm(2588): threadid=7: reacting to signal 3
08-02 11:47:54.476: ERROR/dalvikvm(2588): Unable to open stack trace file '/data/anr/traces.txt': Permission denied
08-02 11:48:01.446: INFO/dalvikvm(2588): Debugger has detached; object registry had 306 entries
08-02 11:48:02.466: DEBUG/ddm-heap(2588): Got feature list request

Answer 1

What sdk version are you using to build the project? If it is above 6 you must make sure you are not using parts of the sdk that has been added after version 6. I'm asking since it seams like you've stepped down the target version from 8 (2.2)

If this does not help, maybe you can post the complete stack trace which might give other clues.