3. ςετ͍ͯ͠ΔͷMockͩ class TheService { public Long calculate(Long a, Long b) { return innerService.calculate(a, b); } } @Test void testCalulate() { InnerService service = mock(InnerService.class): when(service.calculate(19L, 21L)).thenReturn(42L); // ུ Long res = theService.calculate(19L, 21L); assertEquals(LongValueOf(42L), res); }