Androidアプリ - Eclairでヌルポインタ例外を返す

Question

私が書いているAndroidアプリに問題があります。それはNullPointerExceptionのためにEclairでクラッシュするが、FroyoとGingerbreadでは問題なく動作する。誰もがNULLポインタの例外を避けるためにこれを書き換える方法を教えてもらえますか？前もって感謝します。

編集 は、私はもともと間違ってそれを読んだことがあるかもしれない、スタックトレースとlogcatを追加し、それは私のTabWidget可能性のように見えますか？私Homeクラスで

logcat参照このライン：

tabHost.addTab(tabHost.newTabSpec("tab1").setIndicator("Snow", res.getDrawable(R.drawable.weather2)).setContent(new Intent(this,FirstTab.class))); 

Logcat

ERROR/AndroidRuntime(314): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.wilcoxis.android.kirkwood/com.wilcoxis.android.Home}: java.lang.NullPointerException 
ERROR/AndroidRuntime(314):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2496) 
ERROR/AndroidRuntime(314):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2512) 
ERROR/AndroidRuntime(314):  at android.app.ActivityThread.access$2200(ActivityThread.java:119) 
ERROR/AndroidRuntime(314):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1863) 
ERROR/AndroidRuntime(314):  at android.os.Handler.dispatchMessage(Handler.java:99) 
ERROR/AndroidRuntime(314):  at android.os.Looper.loop(Looper.java:123) 
ERROR/AndroidRuntime(314):  at android.app.ActivityThread.main(ActivityThread.java:4363) 
ERROR/AndroidRuntime(314):  at java.lang.reflect.Method.invokeNative(Native Method) 
ERROR/AndroidRuntime(314):  at java.lang.reflect.Method.invoke(Method.java:521) 
ERROR/AndroidRuntime(314):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:860) 
ERROR/AndroidRuntime(314):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:618) 
ERROR/AndroidRuntime(314):  at dalvik.system.NativeStart.main(Native Method) 
ERROR/AndroidRuntime(314): Caused by: java.lang.NullPointerException 
ERROR/AndroidRuntime(314):  at android.widget.TabWidget.onFocusChange(TabWidget.java:351) 
ERROR/AndroidRuntime(314):  at android.view.View.onFocusChanged(View.java:2622) 
ERROR/AndroidRuntime(314):  at android.view.View.handleFocusGainInternal(View.java:2445) 
ERROR/AndroidRuntime(314):  at android.view.ViewGroup.handleFocusGainInternal(ViewGroup.java:404) 
ERROR/AndroidRuntime(314):  at android.view.View.requestFocus(View.java:3562) 
ERROR/AndroidRuntime(314):  at android.view.ViewGroup.requestFocus(ViewGroup.java:976) 
ERROR/AndroidRuntime(314):  at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:1021) 
ERROR/AndroidRuntime(314):  at android.view.ViewGroup.requestFocus(ViewGroup.java:977) 
ERROR/AndroidRuntime(314):  at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:1021) 
ERROR/AndroidRuntime(314):  at android.view.ViewGroup.requestFocus(ViewGroup.java:980) 
ERROR/AndroidRuntime(314):  at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:1021) 
ERROR/AndroidRuntime(314):  at android.view.ViewGroup.requestFocus(ViewGroup.java:977) 
ERROR/AndroidRuntime(314):  at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:1021) 
ERROR/AndroidRuntime(314):  at android.view.ViewGroup.requestFocus(ViewGroup.java:980) 
ERROR/AndroidRuntime(314):  at android.view.View.requestFocus(View.java:3513) 
ERROR/AndroidRuntime(314):  at android.view.View.requestFocus(View.java:3491) 
ERROR/AndroidRuntime(314):  at android.widget.TabHost.setCurrentTab(TabHost.java:334) 
ERROR/AndroidRuntime(314):  at android.widget.TabHost.addTab(TabHost.java:213) 
ERROR/AndroidRuntime(314):  at com.wilcoxis.android.Home.onCreate(Home.java:83) 
ERROR/AndroidRuntime(314):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 
ERROR/AndroidRuntime(314):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2459) 
ERROR/AndroidRuntime(314):  ... 11 more 

スタックトレース

DalvikVM[localhost:8610]  
    Thread [<3> main] (Suspended (exception NullPointerException)) 
     TabWidget.onFocusChange(View, boolean) line: 351  
     TabWidget(View).onFocusChanged(boolean, int, Rect) line: 2622 
     TabWidget(View).handleFocusGainInternal(int, Rect) line: 2445 
     TabWidget(ViewGroup).handleFocusGainInternal(int, Rect) line: 404 
     TabWidget(View).requestFocus(int, Rect) line: 3562 
     TabWidget(ViewGroup).requestFocus(int, Rect) line: 976 
     LinearLayout(ViewGroup).onRequestFocusInDescendants(int, Rect) line: 1021 
     LinearLayout(ViewGroup).requestFocus(int, Rect) line: 977 
     TabHost(ViewGroup).onRequestFocusInDescendants(int, Rect) line: 1021  
     TabHost(ViewGroup).requestFocus(int, Rect) line: 980  
     FrameLayout(ViewGroup).onRequestFocusInDescendants(int, Rect) line: 1021  
     FrameLayout(ViewGroup).requestFocus(int, Rect) line: 977  
     PhoneWindow$DecorView(ViewGroup).onRequestFocusInDescendants(int, Rect) line: 1021 
     PhoneWindow$DecorView(ViewGroup).requestFocus(int, Rect) line: 980 
     PhoneWindow$DecorView(View).requestFocus(int) line: 3513  
     PhoneWindow$DecorView(View).requestFocus() line: 3491 
     TabHost.setCurrentTab(int) line: 334  
     TabHost.addTab(TabHost$TabSpec) line: 213 
     Home.onCreate(Bundle) line: 83 
     Instrumentation.callActivityOnCreate(Activity, Bundle) line: 1047 
     ActivityThread.performLaunchActivity(ActivityThread$ActivityRecord, Intent) line: 2459 
     ActivityThread.handleLaunchActivity(ActivityThread$ActivityRecord, Intent) line: 2512 
     ActivityThread.access$2200(ActivityThread, ActivityThread$ActivityRecord, Intent) line: 119 
     ActivityThread$H.handleMessage(Message) line: 1863 
     ActivityThread$H(Handler).dispatchMessage(Message) line: 99 
     Looper.loop() line: 123 
     ActivityThread.main(String[]) line: 4363  
     Method.invokeNative(Object, Object[], Class, Class[], Class, int, boolean) line: not available [native method] 
     Method.invoke(Object, Object...) line: 521 
     ZygoteInit$MethodAndArgsCaller.run() line: 860 
     ZygoteInit.main(String[]) line: 618 
     NativeStart.main(String[]) line: not available [native method] 
    Thread [<13> Binder Thread #2] (Running)  
    Thread [<11> Binder Thread #1] (Running) 

Answer 1

あなたはヨーヨーケースを処理していませんサービスから空の文字列を返します。実際には、失敗のケースは処理していません。有効なデータが戻ってきていることを確認し、nullの可能性がある参照変数（文字列配列など）で操作しないでください。