Back button Gives force close in TabGroup Activity
<p>I am having four tabs by using tab group acitvity.I have an issue when clicking on back button gives crash but i want to go up to first activity in each tab.</p>

<p>here is my code TabHome.java </p>

<pre><code>super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_NO_TITLE);
        setContentView(R.layout.tab);

        Resources res = getResources(); 
        tabs = getTabHost();  
        TabHost.TabSpec spec; 
        Intent intent;  

        // Create an Intent to launch an Activity for the tab (to be reused)
        //1 -Gebrauchte  Tab
        intent = new Intent().setClass(this,TabBikesGroupActivity.class);

        // Initialize a TabSpec for each tab and add it to the TabHost
        spec = tabs.newTabSpec("gebrauchte").setIndicator("Gebrauchte",
                          res.getDrawable(R.drawable.bike))
                      .setContent(intent);
        tabs.addTab(spec);


        //2 - Produkte
        intent = new Intent().setClass(this, TabProductGroupActivity.class);
        spec = tabs.newTabSpec("produkte").setIndicator("Produkte",
                          res.getDrawable(R.drawable.t_produkt))
                      .setContent(intent);
        tabs.addTab(spec);

        //3 - Handler
        intent = new Intent().setClass(this, TabDealersGroupActivity.class);
        spec = tabs.newTabSpec("handler").setIndicator("Handler",
                          res.getDrawable(R.drawable.haendler))
                      .setContent(intent);
        tabs.addTab(spec);

        //4 - Einstellungen
        intent = new Intent().setClass(this, TabSettingsGroupActivity.class);
        spec = tabs.newTabSpec("einstellungen").setIndicator("Einstellungen",
                          res.getDrawable(R.drawable.t_settings))
                      .setContent(intent);


        tabs.addTab(spec);

     // tabHost.setCurrentTab(1);

   }

    public void switchToTab(int tabid){
        System.out.println("CURRENT TAB "+tabid);
        tabs.setCurrentTab(tabid);
}
</code></pre>

<p>above code describs about tabgroup activity</p>

<p>and 
    Here is my first tab DealersDetailDisplay.java</p>

<pre><code>In that i'm having two button and calling the below methods.When i click on this buttons goes to (Bike search list Activity -&gt; Image adapter -&gt; details activity -&gt;search list Activity -&gt; image adapter -&gt; details activity -&gt; goes same like above)infinite times.Now my problem is when i click on the back button then needs to move activity up to first Bike search list Activity.
</code></pre>

<p>This is my two buttons action listeners.....</p>

<pre><code>    btnAllBikeDetail.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                // TODO Auto-generated method stub
                getBikeSearchForDealer(dealerId);
            }
        });

    btnAllProductDetail.setOnClickListener(new View.OnClickListener() {


            public void onClick(View v) {
                // TODO Auto-generated method stub
                getProductSearchForDealer();
            }
        });
</code></pre>

<p>The below two methods are getting datas from particular url and list out in another activity .After that if i am selecting particular list items then moves to another activity (that is Image adapter) then again click it moves to another one then again you get the above two buttons(same action)this will goes likes this continously...</p>

<pre><code>protected void getBikeSearchForDealer(String dealerId) {
        // TODO Auto-generated method stub
        try {
            URL url = URLComposer.getMotorCycleListUsedByDealerURL(dealerId);
            System.out.println("URL " + url.toString());

            Intent intent=new Intent(getParent(),BikesList.class);              
            intent.putExtra("Search_Result",url.toString());
            TabGroupActivity parentActivity =(TabGroupActivity) getParent();
            parentActivity.startChildActivity("BikeSearch", intent);
        } catch (MalformedURLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    protected void getProductSearchForDealer() {
        // TODO Auto-generated method stub
        try {
            URL url = URLComposer.getDealersProductListURL(dealerId);
            System.out.println("URL " + url.toString());

            Intent intent = new Intent(getParent(), ProductList.class);

            TabGroupActivity parentActivity = (TabGroupActivity) getParent();
            intent.putExtra("Dealer_Search_Result",       url.toString());          
            parentActivity.startChildActivity("productList",
                    intent);
            System.out.println("URL " + url.toString());
        } catch (MalformedURLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
Logcat result is

03-17 14:37:59.760: I/System.out(585): Gallery position :http://www.1000ps.at//images/gebrauchtmotorrad/g_G625147_2.jpg
03-17 14:37:59.900: D/dalvikvm(585): GC_FOR_MALLOC freed 12364 objects / 869712 bytes in 132ms
03-17 14:37:59.931: D/webviewglue(585): nativeDestroy view: 0x3d60c0
03-17 14:37:59.940: D/webviewglue(585): nativeDestroy view: 0x354ac8
03-17 14:38:03.620: I/System.out(585): Gallery position :http://www.1000ps.at//images/gebrauchtmotorrad/g_G625147_3.jpg
03-17 14:38:06.151: I/System.out(585): Gallery position :http://www.1000ps.at//images/gebrauchtmotorrad/g_G625147_3.jpg
03-17 14:38:06.301: D/dalvikvm(585): GC_EXTERNAL_ALLOC freed 4806 objects / 406080 bytes in 147ms
03-17 14:38:06.320: D/webviewglue(585): nativeDestroy view: 0x35c568
03-17 14:38:06.361: D/skia(585): --- decoder-&gt;decode returned false
03-17 14:38:08.303: I/System.out(585): Gallery position :http://www.1000ps.at//images/gebrauchtmotorrad/g_G625147_3.jpg
03-17 14:38:12.480: I/System.out(585): Gallery position :http://www.1000ps.at//images/gebrauchtmotorrad/g_G625147_2.jpg
03-17 14:38:23.981: I/System.out(585): hasUsedBikesnull
03-17 14:38:23.981: I/System.out(585): hasUsedProductsnull
03-17 14:38:24.081: I/System.out(585): hsdjka265204
03-17 14:38:26.191: I/System.out(585): bikeOrder bikeID265204
03-17 14:38:26.191: I/System.out(585): bikeOrder bikeId:265204
03-17 14:38:26.191: I/System.out(585): XML Valueshttp://iphone.1000ps.at/iphone-xml/gebrauchte_suche_result.ashx?suchen_member=265204
03-17 14:38:26.191: I/System.out(585): URL http://iphone.1000ps.at/iphone-xml/gebrauchte_suche_result.ashx?suchen_member=265204
03-17 14:38:26.241: I/System.out(585): Override const
03-17 14:38:26.860: I/System.out(585): Hitting the webservice 
03-17 14:38:26.860: I/System.out(585): DOM :org.apache.harmony.xml.dom.DocumentImpl@450c69e0
03-17 14:38:26.860: I/root node of document(585): BikeResults
03-17 14:38:26.860: I/System.out(585): welcome
03-17 14:38:26.860: I/System.out(585): welcome
03-17 14:38:26.860: I/System.out(585): welcome
03-17 14:38:26.870: I/System.out(585): welcome
03-17 14:38:26.870: I/System.out(585): welcome
03-17 14:38:26.880: I/System.out(585): bikeItemListSize5
03-17 14:38:27.001: I/System.out(585): Pending View
03-17 14:38:27.011: I/System.out(585): Override const
03-17 14:38:27.550: I/System.out(585): Hitting the webservice 
03-17 14:38:27.680: I/System.out(585): DOM :org.apache.harmony.xml.dom.DocumentImpl@45186100
03-17 14:38:27.690: I/root node of document(585): BikeResults
03-17 14:38:29.070: I/System.out(585): Override const
03-17 14:38:29.070: I/System.out(585): XML Valueshttp://iphone.1000ps.at/iphone-xml/gebrauchte_detail.ashx?gid=559645
03-17 14:38:29.640: I/System.out(585): Hitting the webservice 
03-17 14:38:29.640: I/System.out(585): DOM :org.apache.harmony.xml.dom.DocumentImpl@451cad88
03-17 14:38:29.640: I/root node of document(585): document
03-17 14:38:29.670: I/System.out(585): BikeDataSerive, biekId: 559645
03-17 14:38:29.680: I/node list name(585): org.apache.harmony.xml.dom.NodeListImpl@450209a0
03-17 14:38:29.680: I/node values(585): 1
03-17 14:38:29.680: I/node list name(585): org.apache.harmony.xml.dom.NodeListImpl@450202a8
03-17 14:38:29.680: I/node values(585): 1
03-17 14:38:29.680: I/System.out(585): Thumbnail images http://www.1000ps.at//images/gebrauchtmotorrad/g_559645.jpg
03-17 14:38:29.680: I/System.out(585): Thumbnail images http://www.1000ps.at//images/gebrauchtmotorrad/g_559645_2.jpg
03-17 14:38:29.680: I/System.out(585): Thumbnail images http://www.1000ps.at//images/gebrauchtmotorrad/g_559645_3.jpg
03-17 14:38:29.690: I/System.out(585): Thumbnail images http://www.1000ps.at//images/gebrauchtmotorrad/g_559645_4.jpg
03-17 14:38:29.690: I/System.out(585): Original images http://www.1000ps.at//images/gebrauchtmotorrad/g_G559645.jpg
03-17 14:38:29.690: I/System.out(585): Original images http://www.1000ps.at//images/gebrauchtmotorrad/g_G559645_2.jpg
03-17 14:38:29.690: I/System.out(585): Original images http://www.1000ps.at//images/gebrauchtmotorrad/g_G559645_3.jpg
03-17 14:38:29.690: I/System.out(585): Original images http://www.1000ps.at//images/gebrauchtmotorrad/g_G559645_4.jpg
03-17 14:38:29.690: I/node list name(585): org.apache.harmony.xml.dom.NodeListImpl@4522a1c0
03-17 14:38:29.690: I/node values(585): 1
03-17 14:38:29.710: I/System.out(585): BikeDataService email:th.strassnitzky@utanet.at
03-17 14:38:29.710: I/System.out(585): kraft: null
03-17 14:38:33.321: I/System.out(585): Activity Being closeActivities.BikeDetailsDisplay
03-17 14:38:33.321: I/System.out(585): Destroy called
03-17 14:38:34.460: I/System.out(585): Activity Being closeActivities.BikesList
03-17 14:38:34.460: I/System.out(585): Destroy called
03-17 14:38:35.261: I/System.out(585): Activity Being closeActivities.BikeOrder
03-17 14:38:35.261: I/System.out(585): Destroy called
03-17 14:38:35.261: W/System.err(585): java.lang.NullPointerException
03-17 14:38:35.271: W/System.err(585):  at com.InternetGMBH.ThousandPS.Activities.TabGroupActivity.finishFromChild(TabGroupActivity.java:54)
03-17 14:38:35.271: W/System.err(585):  at android.app.Activity.finish(Activity.java:3249)
03-17 14:38:35.271: W/System.err(585):  at com.InternetGMBH.ThousandPS.Activities.TabGroupActivity.onBackPressed(TabGroupActivity.java:108)
03-17 14:38:35.271: W/System.err(585):  at com.InternetGMBH.ThousandPS.Activities.BikeOrder$1.onClick(BikeOrder.java:134)
03-17 14:38:35.271: W/System.err(585):  at android.view.View.performClick(View.java:2408)
03-17 14:38:35.281: W/System.err(585):  at android.view.View$PerformClick.run(View.java:8816)
03-17 14:38:35.281: W/System.err(585):  at android.os.Handler.handleCallback(Handler.java:587)
03-17 14:38:35.281: W/System.err(585):  at android.os.Handler.dispatchMessage(Handler.java:92)
03-17 14:38:35.281: W/System.err(585):  at android.os.Looper.loop(Looper.java:123)
03-17 14:38:35.281: W/System.err(585):  at android.app.ActivityThread.main(ActivityThread.java:4627)
03-17 14:38:35.281: W/System.err(585):  at java.lang.reflect.Method.invokeNative(Native Method)
03-17 14:38:35.281: W/System.err(585):  at java.lang.reflect.Method.invoke(Method.java:521)
03-17 14:38:35.281: W/System.err(585):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
03-17 14:38:35.281: W/System.err(585):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
03-17 14:38:35.281: W/System.err(585):  at dalvik.system.NativeStart.main(Native Method)
03-17 14:39:07.670: I/System.out(585): bikeOrder bikeID265204
03-17 14:39:07.670: I/System.out(585): bikeOrder bikeId:265204
03-17 14:39:07.670: I/System.out(585): XML Valueshttp://iphone.1000ps.at/iphone-xml/gebrauchte_suche_result.ashx?suchen_member=265204
03-17 14:39:07.670: I/System.out(585): URL http://iphone.1000ps.at/iphone-xml/gebrauchte_suche_result.ashx?suchen_member=265204
03-17 14:39:07.730: I/System.out(585): Override const
03-17 14:39:09.020: I/System.out(585): Hitting the webservice 
03-17 14:39:09.020: I/System.out(585): DOM :org.apache.harmony.xml.dom.DocumentImpl@451aca80
03-17 14:39:09.020: I/root node of document(585): BikeResults
03-17 14:39:09.051: I/System.out(585): welcome
03-17 14:39:09.051: I/System.out(585): welcome
03-17 14:39:09.051: I/System.out(585): welcome
03-17 14:39:09.051: I/System.out(585): welcome
03-17 14:39:09.081: I/System.out(585): welcome
03-17 14:39:09.110: I/System.out(585): bikeItemListSize5
03-17 14:39:09.231: I/System.out(585): Pending View
03-17 14:39:09.231: I/System.out(585): Override const
03-17 14:39:10.520: I/System.out(585): Hitting the webservice 
03-17 14:39:10.720: I/System.out(585): DOM :org.apache.harmony.xml.dom.DocumentImpl@4529c450
03-17 14:39:10.740: I/root node of document(585): BikeResults
03-17 14:39:20.171: I/System.out(585): Activity Being closeActivities.BikesList
03-17 14:39:20.171: I/System.out(585): Destroy called
03-17 14:39:20.171: D/AndroidRuntime(585): Shutting down VM
03-17 14:39:20.171: W/dalvikvm(585): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
03-17 14:39:20.201: E/AndroidRuntime(585): FATAL EXCEPTION: main
03-17 14:39:20.201: E/AndroidRuntime(585): java.lang.NullPointerException
03-17 14:39:20.201: E/AndroidRuntime(585):  at com.InternetGMBH.ThousandPS.Activities.TabGroupActivity.finishFromChild(TabGroupActivity.java:54)
03-17 14:39:20.201: E/AndroidRuntime(585):  at android.app.Activity.finish(Activity.java:3249)
03-17 14:39:20.201: E/AndroidRuntime(585):  at com.InternetGMBH.ThousandPS.Activities.TabGroupActivity.onBackPressed(TabGroupActivity.java:108)
03-17 14:39:20.201: E/AndroidRuntime(585):  at com.InternetGMBH.ThousandPS.Activities.BikesList$1.onClick(BikesList.java:67)
03-17 14:39:20.201: E/AndroidRuntime(585):  at android.view.View.performClick(View.java:2408)
03-17 14:39:20.201: E/AndroidRuntime(585):  at android.view.View$PerformClick.run(View.java:8816)
03-17 14:39:20.201: E/AndroidRuntime(585):  at android.os.Handler.handleCallback(Handler.java:587)
03-17 14:39:20.201: E/AndroidRuntime(585):  at android.os.Handler.dispatchMessage(Handler.java:92)
03-17 14:39:20.201: E/AndroidRuntime(585):  at android.os.Looper.loop(Looper.java:123)
03-17 14:39:20.201: E/AndroidRuntime(585):  at android.app.ActivityThread.main(ActivityThread.java:4627)
03-17 14:39:20.201: E/AndroidRuntime(585):  at java.lang.reflect.Method.invokeNative(Native Method)
03-17 14:39:20.201: E/AndroidRuntime(585):  at java.lang.reflect.Method.invoke(Method.java:521)
03-17 14:39:20.201: E/AndroidRuntime(585):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
03-17 14:39:20.201: E/AndroidRuntime(585):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
03-17 14:39:20.201: E/AndroidRuntime(585):  at dalvik.system.NativeStart.main(Native Method)
03-17 14:40:25.580: I/Process(585): Sending signal. PID: 585 SIG: 9

i have addressed only one cycle of activity is working...after that i am getting force close...

only one time only the back button is working after that i am getting force close this is my logcat                                                                                03-17 14:59:42.431: I/System.out(640): Activity Being closeActivities.BikeOrder
03-17 14:59:42.431: I/System.out(640): Destroy called
03-17 14:59:43.180: I/System.out(640): Activity Being closeActivities.BikeDetailsDisplay
03-17 14:59:43.180: I/System.out(640): Destroy called
03-17 14:59:44.360: I/System.out(640): Activity Being closeActivities.BikesList
03-17 14:59:44.360: I/System.out(640): Destroy called
03-17 14:59:44.390: D/AndroidRuntime(640): Shutting down VM
03-17 14:59:44.390: W/dalvikvm(640): threadid=1: thread exiting with uncaught exception (group=0x4001d800)
03-17 14:59:44.400: E/AndroidRuntime(640): FATAL EXCEPTION: main
03-17 14:59:44.400: E/AndroidRuntime(640): java.lang.NullPointerException
03-17 14:59:44.400: E/AndroidRuntime(640):  at com.InternetGMBH.ThousandPS.Activities.TabGroupActivity.finishFromChild(TabGroupActivity.java:54)
03-17 14:59:44.400: E/AndroidRuntime(640):  at android.app.Activity.finish(Activity.java:3249)
03-17 14:59:44.400: E/AndroidRuntime(640):  at com.InternetGMBH.ThousandPS.Activities.TabGroupActivity.onBackPressed(TabGroupActivity.java:108)
03-17 14:59:44.400: E/AndroidRuntime(640):  at com.InternetGMBH.ThousandPS.Activities.BikesList$1.onClick(BikesList.java:67)
03-17 14:59:44.400: E/AndroidRuntime(640):  at android.view.View.performClick(View.java:2408)
03-17 14:59:44.400: E/AndroidRuntime(640):  at android.view.View$PerformClick.run(View.java:8816)
03-17 14:59:44.400: E/AndroidRuntime(640):  at android.os.Handler.handleCallback(Handler.java:587)
03-17 14:59:44.400: E/AndroidRuntime(640):  at android.os.Handler.dispatchMessage(Handler.java:92)
03-17 14:59:44.400: E/AndroidRuntime(640):  at android.os.Looper.loop(Looper.java:123)
03-17 14:59:44.400: E/AndroidRuntime(640):  at android.app.ActivityThread.main(ActivityThread.java:4627)
03-17 14:59:44.400: E/AndroidRuntime(640):  at java.lang.reflect.Method.invokeNative(Native Method)
03-17 14:59:44.400: E/AndroidRuntime(640):  at java.lang.reflect.Method.invoke(Method.java:521)
03-17 14:59:44.400: E/AndroidRuntime(640):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
03-17 14:59:44.400: E/AndroidRuntime(640):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
03-17 14:59:44.400: E/AndroidRuntime(640):  at dalvik.system.NativeStart.main(Native Method)
03-17 14:59:47.831: I/Process(640): Sending signal. PID: 640 SIG: 9
</code></pre>
