inject mock object when ut

inject_mock_object.java

@RunWith(PowerMockRunner.class)
@PrepareForTest({DatasetInfoDao.class, DatasetResource.class})
public class DatasetResourceTest {
  @Test
    public void testIsDumpTimingValidTrue() throws  Exception {
        DatasetInfoDao dao = PowerMockito.mock(DatasetInfoDao.class);
        PowerMockito.when(dao, "getCreatetimeByGroupIdAndDocName", Mockito.any(String.class), Mockito.any(String.class)).thenReturn(null);

        DatasetResource resource = PowerMockito.spy(new DatasetResource());
        MemberModifier.field(DatasetResource.class, "datasetInfoDao").set(resource, dao);

        boolean ret = resource.dumpTimingValidation("1001", "tablename");
        Assert.assertTrue(ret==true);
    }
}