Android:从视图模型更新数据库并对其进行单元测试

// 视图模型类
public class MyViewModel extends ViewModel {
    private MutableLiveData<String> data;
    private MyDatabase database;

    public MyViewModel() {
        data = new MutableLiveData<>();
        database = MyDatabase.getInstance();
    }

    public LiveData<String> getData() {
        return data;
    }

    public void updateData(String newData) {
        data.setValue(newData);
        // 更新数据库
        database.updateData(newData);
    }
}

// 数据库类
public class MyDatabase {
    private static MyDatabase instance;

    private MyDatabase() {
        // 初始化数据库连接
    }

    public static MyDatabase getInstance() {
        if (instance == null) {
            instance = new MyDatabase();
        }
        return instance;
    }

    public void updateData(String newData) {
        // 执行数据库更新操作
    }
}

// 单元测试类
@RunWith(JUnit4.class)
public class MyViewModelTest {
    private MyViewModel viewModel;

    @Before
    public void setup() {
        viewModel = new MyViewModel();
    }

    @Test
    public void testUpdateData() {
        String newData = "New Data";
        viewModel.updateData(newData);
        LiveData<String> data = viewModel.getData();
        assertEquals(newData, data.getValue());
    }
}