Spring Boot MVC测试-MockMvc始终为null

问题描述

我正在尝试编写我的第一个Spring MVC测试，但我只是无法让Spring Boot将MockMvc依赖项注入到我的测试类中.这是我的课程:

I'm trying to write my first Spring MVC test but I just cannot get Spring Boot to inject the MockMvc dependency into my test class. Here is my class:

@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());
  }
}

我已经与IntelliJ的调试器进行了检查，可以确认嘲笑Mvc本身为空.因此，所有异常消息告诉我的是"java.lang.NullPointerException".

I've checked with IntelliJ's debugger and can confirm that mockMvc itself is null. Thus, all the Exception message tells me is "java.lang.NullPointerException".

我已经尝试为"@SpringBootTest"或"@RunWith(SpringRunner.class)"之类的测试类添加更多常规的Spring Boot注释，以防它与初始化Spring无关，但是没有运气.

I've already tried adding more general Spring Boot annotations for test classes like "@SpringBootTest" or "@RunWith(SpringRunner.class)" in case it has something to do with initializing Spring but no luck.

推荐答案

奇怪，前提是您还尝试过使用 @RunWith(SpringRunner.class)和 @SpringBootTest .您是否也尝试过使用 @AutoConfigureMockMvc 批注?下面的示例工作正常.

Strange, provided that you have also tried with @RunWith(SpringRunner.class) and @SpringBootTest. Have you also tried with the @AutoConfigureMockMvc annotation? The sample below is working fine.

@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")));
    }
}

完整示例此处

也许值得考虑以下有关@WebMvcTest和@AutoConfigureMockMvc注释用法的注释，如 Spring的文档

It may also be worthwhile to consider the following comments regarding the usage of the @WebMvcTest and @AutoConfigureMockMvc annotations as detailed in Spring's documentation

@WebMvcTest通常与@MockBean或@Import结合使用，以创建@Controller bean所需的任何协作者.

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

如果您希望加载完整的应用程序配置并使用MockMVC，则应考虑将@SpringBootTest与@AutoConfigureMockMvc结合使用，而不是此注释.

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

使用JUnit 4时，此批注应与@RunWith(SpringRunner.class)结合使用.

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

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