How to mock nested methods in Java

Question

In order to test my program I need to mock a method call like:

entityManager.createQuery("SELECT...", Integer.class).getSingleResult()

the createQuery part returns a TypedQuery<Integer>, but I actually just want to return a single integer: 1. Currently I am using Mockito in order to create my mocks and I am pretty new to this.

Is there a way of testing this?

Thank you!

Yes. That's it. Thank you! I thought too complicated on that one. — Felix, Oct 18 '17 at 07:45
Possible duplicate of [mock nested method calls using mockito](https://stackoverflow.com/questions/41732361/mock-nested-method-calls-using-mockito) — Ahmad Abdelghany, Aug 29 '18 at 13:15

score 4 · Answer 1 · answered Oct 18 '17 at 07:43

4

Assuming you have class EntityManager, Query. You can mock your test like below. (mock(), any(), when() ... methods are in Mockito)

int result = 1;
Query query = mock(Query.class);
EntityManager entityManager = mock(EntityManager.class);

when(entityManager.createQuery(any(), any()).thenReturn(query);
when(query.getSingleResult()).thenReturn(result);

answered Oct 18 '17 at 07:43

SungJin Steve Yoo

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Thank you. Worked for me – Felix Oct 18 '17 at 07:48

score 0 · Answer 2 · answered Oct 18 '17 at 07:44

0

Mock the EntityManager and then you can pre-define the returning-value. Mockito.doReturn(1).when(entityManagerMock).createQuery(any(String.class), any());

answered Oct 18 '17 at 07:44

LenglBoy

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How to mock nested methods in Java

2 Answers2