Spring boot 自动布线服务和存储库抛出空点异常

Question

我正在测试一个简单的初学者 Spring Boot 应用程序，但它不断为我的服务类和我的存储库类抛出。这是我的控制器类：NullPointerException@EnableAutoConfiguration@RestControllerpublic class MyController {    @Autowired    private MyService service;    @GetMapping("/welcome")    public String home throws IOException {        return service.getEntities();    }}这是服务类：@EnableAutoConfiguration@Servicepublic class MyService{@Autowired(required=true)private MyRepository repository;public MyService() {};public List<Entity> getEntities() throws IOException {        return repository.findAll();    }这是存储库：@Repositorypublic interface MyRepository extends JpaRepository<Entity, Long>{    List<Entity> findAll();}因此，如果我运行该应用程序，一切都没问题。问题是当我运行这个测试时：@RunWith(SpringRunner.class)@ContextConfiguration(classes = { MyService.class, MyController.class, Entity.class })@ComponentScan("test.firstproject")@EntityScan(basePackages = {"test.firstproject.entities"})@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)@AutoConfigureTestDatabase(replace = Replace.NONE)@EnableJpaRepositories("test.firstproject.repository")@EnableAutoConfigurationpublic class TestController {    private MockMvc mvc = MockMvcBuilders.standaloneSetup(new MyController).build();    public static final MediaType APPLICATION_JSON_UTF8 = new MediaType(MediaType.APPLICATION_JSON.getType(), MediaType.APPLICATION_JSON.getSubtype(), Charset.forName("utf8"));    }}首先，它在调用 时抛出了 NullPointerException。然后我尝试通过初始化服务来做，但这次抛出了错误。怎么了？service.getEntities()= new MyService()return repository.findAll();

Answer 1

您使用 in line 创建了 MyController：new

private MockMvc mvc = MockMvcBuilders.standaloneSetup(new MyController()).build();

春天可能没有注入它。尝试自动布线：Service

@Autowired

private MyController myController;

并将实例化移动到方法：MockMvc@Before

private MockMvc mvc;

@Before

public void initialize() {

    mvc = MockMvcBuilders.standaloneSetup(myController).build();

}