java - Spring Boot MVC 测试 - MockMvc 始终为空

Question

我正在尝试编写我的第一个 Spring MVC 测试，但我无法让 Spring Boot 将 MockMvc 依赖项注入(inject)我的测试类。这是我的课:

@WebMvcTest
public class WhyWontThisWorkTest {

  private static final String myUri = "uri";
  private static final String jsonFileName = "myRequestBody.json";

  @Autowired
  private MockMvc mockMvc;

  @Test
  public void iMustBeMissingSomething() throws Exception {
    byte[] jsonFile = Files.readAllBytes(Paths.get("src/test/resources/" + jsonFileName));
    mockMvc.perform(
        MockMvcRequestBuilders.post(myUri)
            .content(jsonFile)
            .contentType(MediaType.APPLICATION_JSON))
        .andExpect(MockMvcResultMatchers.status().is2xxSuccessful());
  }
}

我检查了 IntelliJ 的调试器，可以确认 mockMvc 本身为空。因此，所有异常消息告诉我的是“java.lang.NullPointerException”。

我已经尝试为“@SpringBootTest”或“@RunWith(SpringRunner.class)”等测试类添加更通用的 Spring Boot 注释，以防它与初始化 Spring 有关但没有运气。

Answer 1

奇怪，前提是您也尝试过 @RunWith(SpringRunner.class)和 @SpringBootTest .您是否也尝试过 @AutoConfigureMockMvc注解？下面的示例工作正常。

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

    @Autowired
    private MockMvc mockMvc;

    @Test
    public void getHello() throws Exception {
        mockMvc.perform(MockMvcRequestBuilders.get("/").accept(MediaType.APPLICATION_JSON))
                .andExpect(status().isOk())
                .andExpect(content().string(equalTo("Hello World of Spring Boot")));
    }
}

完整样本 here
关于@WebMvcTest 和@AutoConfigureMockMvc 注释的用法，还值得考虑以下评论，详见 Spring's documentation。

By default, tests annotated with @WebMvcTest will also auto-configure Spring Security and MockMvc (include support for HtmlUnit WebClient and Selenium WebDriver). For more fine-grained control of MockMVC the @AutoConfigureMockMvc annotation can be used.

Typically @WebMvcTest is used in combination with @MockBean or @Import to create any collaborators required by your @Controller beans.

If you are looking to load your full application configuration and use MockMVC, you should consider @SpringBootTest combined with @AutoConfigureMockMvc rather than this annotation.

When using JUnit 4, this annotation should be used in combination with @RunWith(SpringRunner.class).