Question

我正在阅读写字符串数组并在回收器视图中显示它们。在显示它们之前，我使用 Collections.reverse（Arrays.asList（FilePathStrings））; 以下是我得到的例外情况：

java.lang.NullPointerException
at java.util.Objects.requireNonNull(Objects.java:203)
at java.util.Arrays$ArrayList.<init>(Arrays.java:3826)
at java.util.Arrays.asList(Arrays.java:3813)
at com.example.soberapps.nightcamera.b.c.a(Unknown Source)
at android.support.v4.app.i.b(Unknown Source)
at android.support.v4.app.o.a(Unknown Source)
at android.support.v4.app.o.e(Unknown Source)
at android.support.v4.app.o.a(Unknown Source)
at android.support.v4.app.c.d(Unknown Source)
at android.support.v4.app.o.b(Unknown Source)
at android.support.v4.app.o.a(Unknown Source)
at android.support.v4.app.o.b(Unknown Source)
at android.support.v4.app.o.h(Unknown Source)
at android.support.v4.app.o$1.run(Unknown Source)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at androidx.test.espresso.base.Interrogator.a(Interrogator.java:19)
at androidx.test.espresso.base.UiControllerImpl.a(UiControllerImpl.java:164)
at androidx.test.espresso.base.UiControllerImpl.a(UiControllerImpl.java:156)
at androidx.test.espresso.base.UiControllerImpl.a(UiControllerImpl.java:34)
at androidx.test.espresso.action.MotionEvents.a(MotionEvents.java:75)
at androidx.test.espresso.action.MotionEvents.a(MotionEvents.java:50)
at androidx.test.espresso.action.Tap.c(Tap.java:8)
at androidx.test.espresso.action.Tap.a(Tap.java:18)
at androidx.test.espresso.action.Tap$1.b(Tap.java:3)
at androidx.test.espresso.action.GeneralClickAction.perform(GeneralClickAction.java:22)
at androidx.test.espresso.ViewInteraction$SingleExecutionViewAction.perform(ViewInteraction.java:9)
at androidx.test.espresso.ViewInteraction.a(ViewInteraction.java:78)
at androidx.test.espresso.ViewInteraction.a(ViewInteraction.java:94)
at androidx.test.espresso.ViewInteraction$1.call(ViewInteraction.java:3)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6316)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:872)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:762)

错误报告崩溃

java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.lang.String.contains(java.lang.CharSequence)' on a null object reference
    at android.os.Parcel.readException(Parcel.java:1689)
    at android.os.Parcel.readException(Parcel.java:1636)
    at android.app.ActivityManagerProxy.handleApplicationCrash(ActivityManagerProxy.java:5217)
    at com.android.internal.os.RuntimeInit$UncaughtHandler.uncaughtException(RuntimeInit.java:97)
    at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:1068)
    at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:1063)

Answer 1

Arrays.asList(null)引发此异常。您的参数（FilePathStrings等于null。

Android在java.util.Objects.requireNonNull（Objects.java:203）处获取空指针异常

1 个答案: