Question

我正在尝试通过使用ActivityUnitTestCase扩展测试类来为我的应用中的活动编写单元测试用例。我可以提前成功运行测试用例，但现在我总是在运行时遇到异常。尽管我对处理NullPointerExceptions非常熟悉，但我无法弄清楚造成这种情况的问题。我找不到任何类似的问题，所以我发布了这个问题。

堆栈跟踪显示我的代码

中的这一行有一个空对象引用

activity = startActivity(mIntent, null, null);

但是startActivity方法应该得到我正在测试的活动的实例。我不确定为什么它会返回null。

这是堆栈跟踪。

java.lang.NullPointerException: Attempt to write to field 'android.os.IBinder android.app.ActivityThread.mLastIntendedActivityToken' on a null object reference
at android.app.Activity.performCreate(Activity.java:6372)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1119)
at android.support.test.runner.MonitoringInstrumentation.callActivityOnCreate(MonitoringInstrumentation.java:346)
at android.test.ActivityUnitTestCase.startActivity(ActivityUnitTestCase.java:158)
at com.abc.test.MainActivityTest.access$100(MainActivityTest.java:16)
at com.abc.test.MainActivityTest$1.run(MainActivityTest.java:34)
at android.app.Instrumentation$SyncRunnable.run(Instrumentation.java:1891)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:145)
at android.app.ActivityThread.main(ActivityThread.java:6117)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1399)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1194)

Test running failed: Instrumentation run failed due to 'java.lang.NullPointerException'

这是测试类

public class MainActivityTest extends ActivityUnitTestCase<MainActivity>{

    private Intent mIntent;
    private MainActivity activity;

    public MainActivityTest() {
        super(MainActivity.class);
    }

    @Override
    protected void setUp() throws Exception {
        super.setUp();
        //Create an intent to launch target Activity as it is not automatically started by Android Instrumentation
        mIntent = new Intent(getInstrumentation().getContext(), MainActivity.class);
        //Start the activity under test in isolation, in the main thread to avoid assertion error.
        getInstrumentation().runOnMainSync(new Runnable() {
            @Override
            public void run() {
                activity = startActivity(mIntent, null, null);
            }
        });
    }

    @Override
    protected void tearDown() throws Exception {
        super.tearDown();
    }

    /**
     * Tests the preconditions of this test fixture.
     */
    @SmallTest
    public void testPreconditions() {
        assertNotNull("MainActivity is null", getActivity());
    }

    @MediumTest
    public void testSecondActivityWasLaunchedWithIntent() {
        // Get the intent for the next started activity
        final Intent launchIntent = getStartedActivityIntent();
        //Verify the intent was not null.
        assertNotNull("Intent was null", launchIntent);
        //Verify that LaunchActivity was finished
        assertTrue(isFinishCalled());
    }
}

Answer 1

@prudhvi不幸的是，我不认为我有一颗银弹，但我建议您尝试按照these steps升级到较新版SDK中的新测试支持库。很抱歉，我无法提供更多帮助！

Answer 2

我有同样的问题。解决方案是使测试成为ActivityInstrumentationTestCase2而不是ActivityUnitTestCase，并在后台为我创建活动

Answer 3

您的应用程序类（即X扩展应用程序）中的某些东西很有可能在早期崩溃。如果是这样的话，你会看到这个错误....检查你的logcat是否有痕迹。

Answer 4

我将 ActivityUnitTestCase 更改为 ActivityInstrumentationTestCase2 并删除了我的 startActivity（）调用（似乎ActivityInstrumentationTestCase2会自动启动活动）现在它再次运行< / p>

由于'java.lang.NullPointerException'导致Instrumentation运行失败

4 个答案: