java.lang.NoSuchMethodError：沒有靜態方法clearInstance（）

Question

我正在嘗試在Android Studio中運行測試，測試設置拋出了java.lang.NoSuchMethodError

測試：

@RunWith(AndroidJUnit4.class)
@LargeTest
public class MusicLocalDataSourceTest {
    private Context context;
    private final static String TITLE_1 = "TITLE 1";
    private final static String ID_1 = "1";
    private final static String ARTISTIC_1 = "ARTISTIC 1";


    private DataSource<Music> mMusicDataSource;
    private StapeDatabase mDatabase;

    @Before
    public void setup() {
        context = InstrumentationRegistry.getTargetContext();
        mDatabase = Room
                .inMemoryDatabaseBuilder(context, StapeDatabase.class)
                .build();

        IEMusicDao dao = mDatabase.musicDao();

        MusicLocalDataSource.clearInstance(); // throws error
        mMusicDataSource = MusicLocalDataSource.getInstance(new SingleExecutor(), dao);
    }

    @After
    public void cleanUp() {
        mDatabase.close();
        MusicLocalDataSource.clearInstance();
    }

    @Test
    public void should_not_have_null_instance() {
        assertNotNull(mMusicDataSource);
    }
}

classe que estou testando:
class being tested:

public class MusicLocalDataSource implements IEMusicDataSource<Music> {
    private static volatile MusicLocalDataSource INSTANCE;
    private IEMusicDao musicDao;
    private AppExecutors appExecutors;

    private MusicLocalDataSource(@NonNull AppExecutors appExecutors, @NonNull IEMusicDao musicDao) {
        this.appExecutors = appExecutors;
        this.musicDao = musicDao;
    }

    public static MusicLocalDataSource getInstance(@NonNull AppExecutors appExecutors, @NonNull
                                                   IEMusicDao musicDao) {

        if (INSTANCE ==  null) {
            synchronized (MusicLocalDataSource.class) {
                if (INSTANCE == null) {
                    INSTANCE = new MusicLocalDataSource(appExecutors, musicDao);
                }
            }
        }

        return INSTANCE;
    }

    @Override
    public void findAll(@NonNull LoadDataCallback<Music> callback) {
        Runnable runnable = () -> {
          final List<Music> musics = musicDao.findAll();
          this.appExecutors.mainThread().execute(() -> {
              if (musics.isEmpty()) {
                  callback.onDataNotAvailable();
              } else {
                  callback.onDataLoaded(musics);
              }
          });
        };

        appExecutors.diskIO().execute(runnable);
    }

    @Override
    public void findById(@NonNull String dataId, @NonNull GetDataCallback<Music> callback) {
        Runnable runnable = () -> {
            final Music music = musicDao.findMusicById(dataId);

            appExecutors.mainThread().execute(() -> {
                if(music != null) {
                    callback.onDataLoaded(music);
                } else {
                    callback.onDataNotAvailable();
                }
            });
        };

        appExecutors.diskIO().execute(runnable);
    }

    @Override
    public void save(@NonNull Music data) {

    }

    @Override
    public void update(@NonNull Music data) {

    }

    @Override
    public void delete(@NonNull Music data) {

    }

    @Override
    public void delete(@NonNull String dataId) {

    }

    @Override
    public void deleteAll() {

    }

    @VisibleForTesting
    static void clearInstance() {
        INSTANCE = null;
    }

跟蹤：

  java.lang.NoSuchMethodError: No static method clearInstance()V in class 

Lcom / stapeapp / stape / music / domain / datasource / MusicLocalDataSource; 或其超級類（com.stapeapp.stape.music.domain.datasource.MusicLocalDataSource的聲明出現在/data/app/com.stapeapp.stape.mock-2/base.apk中）在com.stapeapp.stape處。 org處java.lang.reflect.Method.invoke（Native Method）處的music.domain.datasource.MusicLocalDataSourceTest.cleanUp（MusicLocalDataSourceTest.java:56）在組織處java.lang.reflect.Method.invoke（Method.java:372）在org.junit.internal.runners.model.ReflectiveCallable.run（ReflectiveCallable.java:12）處的junit.runners.model.FrameworkMethod $ 1.runReflectiveCall（FrameworkMethod.java:50）在org.junit.runners.model.FrameworkMethod.invokeExplosively （FrameworkMethod.java:47）在android.support.test.internal.runner.junit4.statement.RunAfters.evaluate（RunAfters.java:80）在org.junit.runners.ParentRunner.runLeaf（ParentRunner.java:325）在org.junit.runners.BlockJUnit4ClassRunner.runChild（BlockJUnit4ClassRunner.java:78）在org.junit.runners.BlockJUnit4ClassRunner.runChild（BlockJUnit4ClassRunner.java:57）在org.junit.runners.ParentRunner $ 3.在org.junit.runners.ParentRunner處運行（ParentRunner.java:290）在org.junit.runners.ParentRunner.runChildren（ParentRunner.java:288）處的schedule（ParentRunner.java:71）在org.junit處的運行。在org.junit.runners.ParentRunner $ 2.evaluate（ParentRunner.java:268）在org.junit.runners.ParentRunner.run（ParentRunner.java:363）處的Runners.ParentRunner.access $ 000（ParentRunner.java:58） org.junit.runners.Suite.runChild（Suite.java:27）上的.junit.runners.Suite.runChild（Suite.java:128），org.junit.runners.ParentRunner $ 3.run（ParentRunner.java:290）在org.junit.runners.ParentRunner $ 1.schedule（ParentRunner.java:71）在org.junit.runners.ParentRunner.runChildren（ParentRunner.java:288）在org.junit.runners.ParentRunner.access $ 000（ParentRunner.java） ：58）在org.junit.runners.ParentRunner上$ 2.evaluate（ParentRunner.java:268）在org.junit.runners.ParentRunner.run（ParentRunner.java:363）在org.junit.runner.JUnitCore.run（JUnitCore） .java：137），位於org.junit.runner.JUnitCore.run（JUnitCore.java:115），位於android.support.test.internal。 android.support.test.runner.AndroidJUnitRunner.onStart（AndroidJUnitRunner.java:375）上的Runner.TestExecutor.execute（TestExecutor.java:58）android.app.Instrumentation $ InstrumentationThread.run（Instrumentation.java:1871）

有人知道發生了什么事和/或可以給我一些指示嗎？

編輯：當我在其他測試中創建實體的新實例時，再次發生此錯誤，該實體在測試中是靜態屬性。

public class IEMusicDaoTest {
    private static final Music MUSIC = new Music("1", "title", "artistic"); // error occurred here
    private StapeDatabase mDatabase;

    @Before
    public void setUp() throws Exception {
        Context context = InstrumentationRegistry.getContext();
        mDatabase = Room.inMemoryDatabaseBuilder(context, StapeDatabase.class).build();
    }

    @After
    public void tearDown() throws Exception {
        mDatabase.close();
    }

    @Test
    public void should_have_success_in_save_music() {
        mDatabase.musicDao().save(MUSIC);

        Music loaded = mDatabase.musicDao().findMusicById(MUSIC.getId());

        assertMusic(loaded, MUSIC.getId(), MUSIC.getName(), MUSIC.getArtist());

    }

    private void assertMusic(Music loaded, String id, String name, String artist) {
        Assert.assertThat(loaded, CoreMatchers.notNullValue());
        Assert.assertThat(loaded.getId(), CoreMatchers.is(id));
        Assert.assertThat(loaded.getName(), CoreMatchers.is(name));
        Assert.assertThat(loaded.getArtist(), CoreMatchers.is(artist));
    }

Answer 1

通常檢查引入該類方法的版本 。 如果該方法是在較新的版本中引入的，則編譯器會接受，但如果在較舊的平台上運行，則會在運行時出現錯誤！