TestMockitoInjection.java

@ExtendWith(MockitoExtension.class)
public class TestMockitoInjection {
	private BoringService service;

	public TestMockitoInjection(@Mock BoringService service) {
		this.service = service;
	}

	@Test
	public void testConstructorInjectedValue() {
		when(service.returnNumber()).thenReturn(2);
		assertEquals(2, service.returnNumber());
	}

	@Test
	public void testMethodInjection(@Mock BoringService service) {
		when(service.returnNumber()).thenReturn(3);
		assertEquals(3, service.returnNumber());
	}

	public class BoringService {
		public int returnNumber() {
			return 1;
		}
	}
}