如何使用SpringBoot进行单元测试？

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

@RunWith(SpringRunner.class)
@SpringBootTest
public class MyServiceTest {

    @Autowired
    private MyService myService;

    @MockBean
    private MyRepository myRepository;

    @Test
    public void testServiceMethod() {
        // 模拟数据库查询结果
        when(myRepository.findById(1L)).thenReturn(Optional.of(new MyEntity("Test")));

        // 调用服务方法并断言结果
        String result = myService.getDataById(1L);
        assertEquals("Test", result);
    }
}

@SpringBootTest
public class MyControllerTest {

    @Autowired
    private MockMvc mockMvc;

    @Test
    public void testGetEndpoint() throws Exception {
        mockMvc.perform(get("/api/myendpoint"))
               .andExpect(status().isOk())
               .andExpect(content().string("Hello, World!"));
    }
}

@WebMvcTest(MyController.class)
public class MyControllerTest {

    @Autowired
    private MockMvc mockMvc;

    @Test
    public void testController() throws Exception {
        mockMvc.perform(get("/api/test"))
               .andExpect(status().isOk())
               .andExpect(jsonPath("$.name").value("Test"));
    }
}

@RunWith(SpringRunner.class)
@SpringBootTest
public class MyServiceTest {

    @Autowired
    private MyService myService;

    @MockBean
    private MyRepository myRepository;

    @Test
    public void testServiceMethod() {
        // 使用 Mockito 模拟返回值
        when(myRepository.findById(1L)).thenReturn(Optional.of(new MyEntity("Test")));

        String result = myService.getDataById(1L);
        assertEquals("Test", result);
    }
}

@DataJpaTest
public class MyRepositoryTest {

    @Autowired
    private MyRepository myRepository;

    @Test
    public void testFindById() {
        MyEntity entity = myRepository.save(new MyEntity("Test"));

        Optional<MyEntity> result = myRepository.findById(entity.getId());
        assertTrue(result.isPresent());
        assertEquals("Test", result.get().getName());
    }
}

@RunWith(SpringRunner.class)
@WebMvcTest(MyController.class)
public class MyControllerTest {

    @Autowired
    private MockMvc mockMvc;

    @Test
    public void testGetMapping() throws Exception {
        mockMvc.perform(get("/api/example"))
               .andExpect(status().isOk())
               .andExpect(content().string("Hello, World!"));
    }
}

@Test
public void testCalculation() {
    int result = myService.calculate(2, 3);
    assertEquals(5, result);
}