关闭网络后，AdWhirl导致java.lang.NullPointerException

时间：2012-05-17 03:08:32

标签： android nullpointerexception admob android-viewpager adwhirl

我在我的一个应用程序中使用了AdWhirl和Admob，发布后，我们从adwhirl那里得到了很多错误，并且它很容易像这样重现：

广告出现后，我关闭了wifi，等待广告超时，然后按返回按钮退出应用程序。

然后出现错误.src可以从this下载。异常是这样的：

 05-17 11:00:13.265: E/AndroidRuntime(12482): java.lang.RuntimeException: Unable to destroy activity {me.test.admob/me.test.admob.AdWhirlTestActivity}: java.lang.NullPointerException
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.app.ActivityThread.performDestroyActivity(ActivityThread.java:3112)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.app.ActivityThread.handleDestroyActivity(ActivityThread.java:3130)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.app.ActivityThread.access$1200(ActivityThread.java:123)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1180)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.os.Handler.dispatchMessage(Handler.java:99)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.os.Looper.loop(Looper.java:137)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.app.ActivityThread.main(ActivityThread.java:4424)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at java.lang.reflect.Method.invokeNative(Native Method)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at java.lang.reflect.Method.invoke(Method.java:511)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at dalvik.system.NativeStart.main(Native Method)
05-17 11:00:13.265: E/AndroidRuntime(12482): Caused by: java.lang.NullPointerException
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.webkit.WebView.requestFocus(WebView.java:7650)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2154)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.requestFocus(ViewGroup.java:2110)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2154)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.requestFocus(ViewGroup.java:2110)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2154)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.requestFocus(ViewGroup.java:2110)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2154)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.requestFocus(ViewGroup.java:2110)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2154)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.requestFocus(ViewGroup.java:2110)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2154)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.requestFocus(ViewGroup.java:2110)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.onRequestFocusInDescendants(ViewGroup.java:2154)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.requestFocus(ViewGroup.java:2113)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.View.requestFocus(View.java:5323)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewRootImpl.clearChildFocus(ViewRootImpl.java:2200)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.clearChildFocus(ViewGroup.java:669)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.clearChildFocus(ViewGroup.java:669)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.clearChildFocus(ViewGroup.java:669)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.clearChildFocus(ViewGroup.java:669)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.clearChildFocus(ViewGroup.java:669)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.removeViewInternal(ViewGroup.java:3591)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.removeViewInternal(ViewGroup.java:3561)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.view.ViewGroup.removeView(ViewGroup.java:3509)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:998)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1080)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1062)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.support.v4.app.FragmentManagerImpl.dispatchDestroy(FragmentManager.java:1843)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.support.v4.app.FragmentActivity.onDestroy(FragmentActivity.java:314)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.app.Activity.performDestroy(Activity.java:4629)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.app.Instrumentation.callActivityOnDestroy(Instrumentation.java:1079)
05-17 11:00:13.265: E/AndroidRuntime(12482):    at android.app.ActivityThread.performDestroyActivity(ActivityThread.java:3099)
05-17 11:00:13.265: E/AndroidRuntime(12482):    ... 11 more

在我的测试之后，我发现只有在ViewPager中使用带有ListFragment的adwhirl时才会出现此异常。如果我只在ListFragment中使用或在ViewPager中使用Fragment，它可以正常工作。 但我仍然想知道什么是错的，我怎么能解决这个例外。

任何答案都将不胜感激。

3 个答案:

答案 0 :(得分：1)

  1. 确保在onDestroy（）方法
    2. 中处理AdWhirl
  2. 使用try catch来捕获NullPointer，联系开发人员并希望他们能解决这个问题（如果它是一个bug）

答案 1 :(得分：0)

始终检查带有连接的对象的内容

if(conection !=null){
execute();
}

因为您使用webView始终会在执行前检查您的手机连接是否已打开 这应该会停止nullpointer

如果没有代码示例，很难提供更好的见解

但您可以使用连接管理器检查下面的波纹管是一个如何检查wifi的示例

public boolean isOnWifi(Context context) {
    ConnectivityManager connManager = (ConnectivityManager) context
            .getSystemService(CONNECTIVITY_SERVICE);
    NetworkInfo mWifi = connManager
            .getNetworkInfo(ConnectivityManager.TYPE_WIFI);

    if (mWifi.isConnected()) {
        return true;
    }

    return false;
}

查看是否存在蜂窝连接只需将ConnectivityManager.TYPE_WIFI更改为 ConnectivityManager.TYPE_MOBILE

答案 2 :(得分：0)

查找AdMob或AdWhirl每隔几秒或几分钟尝试更改广告横幅的功能。发生此异常是因为该函数中没有异常处理程序。关闭wifi后，一些代码期望正常工作的互联网连接，但不再有连接。最好试试这个：

  1. 转到每隔x秒/分钟更改广告横幅的功能。
  2. 你需要用异常处理程序包围代码，例如试着抓。并捕获NullPointerException。
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