<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-test</artifactId>
   <scope>test</scope>
</dependency>

@SpringBootTest
public class ProductImageServiceImplMockito {
 
    @Mock
    private ProductImageMapper productImageMapper;
 
    @InjectMocks
    private ProductImageServiceImpl productImageService;
 
 
    @BeforeEach
    public void setup() {
        MockitoAnnotations.openMocks(this);
    }
 
 
    @Test
    public void testGet() {
        ProductImage productImage = new ProductImage();
        productImage.setId(1l);
        productImage.setImageUrl("mockUrl");
        // mock方法的邏輯
        when(productImageMapper.selectById(1l)).thenReturn(productImage);
        ProductImage image = productImageService.getByImageId(1l);
        assertEquals("mockUrl", image.getImageUrl());
    }
}

// Controller層代碼
@RestController
@RequestMapping("/test")
public class ProductImageController {
 
    @Autowired
    private ProductImageServiceImpl productImageService;
 
    @GetMapping("/productImage/{id}")
    public ProductImage getProductById(@PathVariable("id") Long id) {
        return productImageService.getByImageId(id);
    }
}
 
// 測試方法代碼
@WebMvcTest(ProductImageController.class)
public class ProductImageServiceImplMockitoV2 {
 
    @MockBean
    private ProductImageServiceImpl productImageService;
 
    @Autowired
    private MockMvc mockMvc;
 
    @Test
    public void test() throws Exception {
        ProductImage productImage = new ProductImage();
        productImage.setId(1l);
        productImage.setImageUrl("mockUrl");
        when(productImageService.getByImageId(1l)).thenReturn(productImage);
        MvcResult mvcResult = mockMvc.perform(MockMvcRequestBuilders.get("/test/productImage/1"))
                .andExpect(status().isOk())
                .andReturn();
        String contentAsString = mvcResult.getResponse().getContentAsString();
    }
}