Mocking of new object and injecting it - junit

Question

I want to write junit for below method
public class ManageProfile{
public ResponseDTO create(SessionContext context, String flowId, Map<String, String> params) {
ApiClient apiClient=new ApiClient();
apiClient.setBasePath("ip");
Service service=new Service();
service.setApiClient(apiClient);
ResponseDTO response= service.createProfile(new RequestDto());
return response;
}
}
Its not spring based application.
class Test
#Test
public void testCreate() {
SessionContext sessionContext = mock(SessionContext.class);
ManageProfile manageProfile=new ManageProfile();
Service service=mock(Service.class);
when(service.createProfile(any())).thenReturn(new ResponseDTO());
String flowId = "1";
Map<String, String> params = new HashMap<>();
ResponseDTO responseDTO=manageProfile.create(sessionContext,flowId,params);
Assert.assertEquals("123"responseDTO.getId);
}
}
I am not able to inject mock Service object in ManageProfile as it is getting created using new keyword

Answer 1

Use spy to mock some methods in ManageProfile class
public class ManageProfile{
public ResponseDTO create(SessionContext context, String flowId, Map<String, String> params) {
ApiClient apiClient=new ApiClient();
apiClient.setBasePath("ip");
Service service = createService();
...
}
public Service createService(){
return new Service();
}
class Test {
#Test
public void testCreate() {
SessionContext sessionContext = mock(SessionContext.class);
ManageProfile manageProfile= spy(new ManageProfile());
Service service=mock(Service.class);
when(mangaeProfile.createService()).thenReturn(service);
...
}