Junit code coverage in not covering the code in java using eclemma

Question

I have written the junit test case of a API helper class but when I am checking the code coverage, the helper class is showing as 0 percent. I am not sure what is the issue.

Here is the sample code:

public Class ClassHelper{
   public Response invoke() {

   ClassVO classVO = new ClassVO(pString);
   ClassOutputVO outputVO = getSoapServiceBridgeProvider().getSoapServiceBridge(classVO).invokeProces()
...
  return response
  }
}

the testclass is given below:

@Test
public void testInvoke() throws Exception{
PowerMockito.whenNew(ClassVO.class).withArguments(Mockito.anyString()).thenReturn(mockVO);

Response actualResponse = (Response) classHelper.invoke();

can someone please help me with the issue? Its working with other helper classes but only happening with api helpers.

the working example has below:

 @Component
 public class TestHelper {
 public Reponse updateRole(Request request) throws Exception {
       ClassVO vo = new ClassVO();
       vo.setRoleId(request.getRoleId());
       vo.setRoleName(request.getRoleName());
       Response response = new Response;
                response.setRoleId(vo.getRoleId());
                response.setRoleName(vo.getRoleName));
 }
 }

Test class:

@ContextConfiguration
@RunWith(PowerMockRunner.class)
@PowerMockIgnore("javax.management.*")
@PrepareForTest({ DriverManager.class })
public class TestHelperTest { 
 @InjectMocks
 private TestHelper testHelper;

 @Test
 public void testUpdateRole() throws ADTMBaseException{
    Request request = new Request();
    request.setRoleId(8);
    request.setRoleName(JUnitTestConstants.ROLE_NAME);
    Reponse actualResult = testHelper.updateRole(request);
}