java - Spring MVC 测试失败

Question

我正在尝试运行 Spring MVC 测试，但一直收到此异常。

org.springframework.web.util.NestedServletException:请求处理失败；嵌套异常是 java.lang.NullPointerException

异常发生是因为 Autowiring 的依赖，

    @Autowired
    private AccountService accountService;

未在测试中注入(inject)(在测试外工作正常)。

谁能帮我解决这个问题。这是我的代码:

//AccountControllerITTest类

@RunWith(SpringJUnit4ClassRunner.class)
@SpringApplicationConfiguration(classes = MockServletContext.class)
@WebAppConfiguration
public class AccountControllerITest {

private MockMvc mvc;

ObjectMapper om;

@Before
public void setUp() throws Exception {
    mvc = MockMvcBuilders.standaloneSetup(new AccountController()).build();
}

@Test
public void getAccounts() throws Exception {
    MvcResult mvcResult =     mvc.perform(MockMvcRequestBuilders.get("/api/accounts"))
            .andExpect(status().isOk())
            .andReturn();
}    
}

//账户 Controller

@RestController
@RequestMapping("/api/accounts")
public class AccountController {

@Autowired
private AccountService accountService;

@RequestMapping(method = RequestMethod.GET)
public ResponseEntity<Set<AccountInfo>> getAccounts(@RequestParam(value = "firstName", required = false) String firstName,
                                                    @RequestParam(value = "surName", required = false)  String surName) {
    Set<AccountInfo> accounts = accountService.getAccounts(firstName, surName);
    return new ResponseEntity<>(accounts, HttpStatus.OK);
}

感谢您的帮助!

Answer 1

因为您使用的是独立设置:mvc = MockMvcBuilders.standaloneSetup(new AccountController()).build();。如果您通过 new AccountController() 创建 Controller ，Spring 没有机会注入(inject) accountService，因为它不控制实例创建和连接。

你有两个选择:

1. 将您的测试切换为单元测试，并且不要使用 SpringJUnit4ClassRunner 或 MockServletContext全部。您可以使用 @InjectMocks 注入(inject)私有(private) accountService:

   public class AccountControllerITest {
   
       private MockMvc mvc;
   
       ObjectMapper om;
   
       @Mock
       private AccountController accountController = new AccountController();
   
       @InjectMocks
       private AccountService accountService = new Mockito.mock(AccountService.class);
   
       @Before
       public void setUp() throws Exception {
           mvc = MockMvcBuilders.standaloneSetup(accountController).build();
       }
   

   您还可以将增强功能应用于您的 Controller 。将字段注入(inject)替换为构造函数注入(inject)，您可以在测试中通过构造函数将 accountService 传递给 Controller ​​。这样你就不需要使用 @InjectMocks 了。

2. 使用 webAppContext 设置:

   @Autowired
   private WebApplicationContext webApplicationContext;
   
   @BeforeMethod
   public void init() {
       mockMvc = MockMvcBuilders.webAppContextSetup(webApplicationContext).build();
   }