Spring - 如何正確使用@Autowired 來防止控制器/MockMvc 為空？

Question

我正在嘗試運行一些單元測試並遇到一個問題，我確信該問題源於對自動裝配的誤解。 我有一個單元測試類，我試圖在其中使用@Autowired在 MockMvc 和 REST 控制器上——這兩個最終都是空的。

我已經看到一些來源試圖解釋為什么會發生這種情況（包括這篇更多的更少的帖子和一個有用的StackOverflow 帖子，它給了我一些見解，但並沒有完全幫助我解決我的問題）。

以下是我為重現此問題而制作的示例項目中的相關源代碼。

ManagerControllerTest.java

@RunWith(SpringRunner.class)
@WebMvcTest(ManagerController.class)
public class ManagerControllerTest {
    @Autowired
    private MockMvc mockMvc;

    @MockBean
    private Manager manager;

    @Autowired
    private ManagerController controller;

    @Test
    public void controllerNotNull() throws Exception {
        assertThat(controller).isNotNull();
    }

    @Test
    public void testStoreSomething() throws Exception {
        String path = "/manager/store-something/";

        MockHttpServletRequestBuilder builder = MockMvcRequestBuilders.get(path)
                    .characterEncoding("UTF-8")
                    .contentType(MediaType.APPLICATION_JSON);

        MvcResult result = mockMvc.perform(builder).andReturn();
        assertEquals(HttpStatus.CREATED, result.getResponse().getStatus());
    }
}

controllerNotNull()測試結果

java.lang.AssertionError：期望實際不為空

雖然奇怪的是，當我用 Java 創建一個新的 Gradle 項目並將我的示例代碼從這篇文章導入到其中時， controllerNotNull()通過了。

和testStoreSomething()結果

java.lang.NullPointerException 在 com.example.sandbox.rest.ManagerControllerTest.testStoreSomething(ManagerControllerTest.java:46)

問題就在這里：我誤解了什么？ 我究竟做錯了什么？ 我可以從控制器中刪除@Autowired並使用new ManagerController()實例化它，但我留下了 MockMvc 問題。

管理器控制器.java

@Controller
@RequestMapping(value = "/manager/")
public class ManagerController {
    Manager manager = new Manager(new StringStorage());

    @PostMapping(value = "store-something")
    private ResponseEntity<?> storeSomething(String str) {
        manager.storeSomething(str);
        return new ResponseEntity<>(CREATED);
    }
}

管理器

public class Manager {
    private final Storage storage;

    public Manager(Storage storage) {
        this.storage = storage;
    }

    public void storeSomething(String str) {
        storage.store(str);
    }
}

存儲.java

public interface Storage {
    void store(String str);
}

字符串存儲

public class StringStorage implements Storage {
    Map<String, String> stringMap;

    @Override
    public void store(String str) {
        stringMap.put(str, str);
    }
 }

應用程序.java

@SpringBootApplication
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

}

build.gradle已從原始帖子（使用 JUnit4）中編輯，但問題仍然存在。

repositories {
    jcenter()
}

apply plugin: 'java'
apply plugin: 'eclipse'

dependencies {
 compile group: 'org.springframework.boot', name: 'spring-boot-starter-web', version: '2.0.0.RELEASE'
    compile group: 'org.springframework.boot', name: 'spring-boot-starter-tomcat', version: '2.0.0.RELEASE'

    testCompile group: 'org.springframework.boot', name: 'spring-boot-starter-test', version: '2.0.0.RELEASE'
    testImplementation 'org.junit.jupiter:junit-jupiter-api:4.0.0'
    testImplementation 'org.junit.jupiter:junit-jupiter-params:4.0.0'
    testCompile group: 'org.mockito', name: 'mockito-core', version: '2.17.0'
    testCompile group: 'org.junit.jupiter', name: 'junit-jupiter-engine', version: "4.0.0"
    testCompile group: 'org.junit.platform', name: 'junit-platform-launcher', version: "1.3.1"
}

Answer 1

@RestController
@RequestMapping(value = "/manager")
public class ManagerController {

    @Autowired
    Manager manager;

    @PostMapping(value = "/store-something")
    private ResponseEntity<?> storeSomething(String str) {
        manager.storeSomething(str);
        return new ResponseEntity<>(CREATED);
    }
}


@Component
public class Manager {

    @Autowired
    private Storage storage;

    public void storeSomething(String str) {
        storage.store(str);
    }
}


public interface Storage {
    void store(String str);
}

@Service
public class StringStorage implements Storage {
    Map<String, String> stringMap = new HashMap<>();

    @Override
    public void store(String str) {
        stringMap.put(str, str);
    }
 }




@SpringBootApplication
public class Application {

    public static void main(String[] args) {
        SpringApplication.run(Application.class, args);
    }

}

測試類：

@RunWith(SpringRunner.class)
@SpringBootTest
@AutoConfigureMockMvc
public class ApplicationTest {

    @Autowired
    private MockMvc mockMvc;

    @Test
    public void shouldReturnDefaultMessage() throws Exception {
        this.mockMvc.perform(post("/manager/store-something")).andDo(print()).andExpect(status().isOk())
                .andExpect(content().string(containsString("Hello World")));
    }
}

Answer 2

將注釋 AutoConfigureMockMvc 添加到您的測試類

@RunWith(SpringRunner.class)
@AutoConfigureMockMvc
public class ManagerControllerTest {
    @Autowired
    private MockMvc mockMvc;

    @MockBean
    private Manager manager;

    @Autowired
    private ManagerController controller;

    @Test
    public void controllerNotNull() throws Exception {
        assertThat(controller).isNotNull();
    }

    @Test
    public void testStoreSomething() throws Exception {
        this.mvc.perform(get("/manager/store-something/"))
        .contentType(MediaType.APPLICATION_JSON)
        .andExpect(status().isOk())

    }

或者，您也可以將 TestRestTemplate 與 @SpringBootTest(webEnvironment= SpringBootTest.WebEnvironment.RANDOM_PORT) 一起使用