我的应用程序中有一些奇怪的 NullPointerException。
我运行这段代码:
protected void onPostExecute(Void result)
{
Log.i("name1", userProfilePictures[positionForPicture][0]);
if(movedToAnotherActivity)
return;
if(loadNewPosts && loaded10More == false)
{
firstLoopPicture = true;
positionForPicture = 0;
return;
}
if((positionForPicture == userProfilePictures.length) == false)
{
new GetUserPicture().execute();
int loadLength = loadedPostsSaverForPictures.length;
String name = userProfilePictures[positionForPicture][0];
Log.i("name", name);
}
}
…………
我在这一行得到空指针异常:
String name = userProfilePictures[positionForPicture][0];
Log.i("name", name);
日志猫:
08-28 17:39:28.140: E/AndroidRuntime(26801): FATAL EXCEPTION: main
08-28 17:39:28.140: E/AndroidRuntime(26801): java.lang.NullPointerException: println needs a message
08-28 17:39:28.140: E/AndroidRuntime(26801): at android.util.Log.println_native(Native Method)
08-28 17:39:28.140: E/AndroidRuntime(26801): at android.util.Log.i(Log.java:159)
08-28 17:39:28.140: E/AndroidRuntime(26801): at com.example.workoutlog.WorkoutsWall$GetUserPicture.onPostExecute(WorkoutsWall.java:3420)
08-28 17:39:28.140: E/AndroidRuntime(26801): at com.example.workoutlog.WorkoutsWall$GetUserPicture.onPostExecute(WorkoutsWall.java:1)
08-28 17:39:28.140: E/AndroidRuntime(26801): at android.os.AsyncTask.finish(AsyncTask.java:631)
08-28 17:39:28.140: E/AndroidRuntime(26801): at android.os.AsyncTask.access$600(AsyncTask.java:177)
08-28 17:39:28.140: E/AndroidRuntime(26801): at android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
08-28 17:39:28.140: E/AndroidRuntime(26801): at android.os.Handler.dispatchMessage(Handler.java:99)
08-28 17:39:28.140: E/AndroidRuntime(26801): at android.os.Looper.loop(Looper.java:137)
08-28 17:39:28.140: E/AndroidRuntime(26801): at android.app.ActivityThread.main(ActivityThread.java:5226)
08-28 17:39:28.140: E/AndroidRuntime(26801): at java.lang.reflect.Method.invokeNative(Native Method)
08-28 17:39:28.140: E/AndroidRuntime(26801): at java.lang.reflect.Method.invoke(Method.java:511)
08-28 17:39:28.140: E/AndroidRuntime(26801): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:795)
08-28 17:39:28.140: E/AndroidRuntime(26801): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:562)
08-28 17:39:28.140: E/AndroidRuntime(26801): at dalvik.system.NativeStart.main(Native Method)
奇怪的是,在这行之前我有这个代码:
Log.i("name1", userProfilePictures[positionForPicture][0]);
这给了我字符串而不是空错误。
为什么我得到空指针异常?它是相同的字符串...