spring boot 单元测试使用new MockMvc和@RunWith+@AutoConfigureMockMvc注解的区别

在单元测试中用以上两种都能实现，但是@RunWith注解还可以实现代码中的依赖注入(前者不能)

单测代码如下

Slf4j@RestController@RequestMapping("/rest")public class ArticleRestController {@ResourceArticleRestService articleRestService;/** * 增加一篇文章 * * @param article * @retu */// @RequestMapping(value = "/article", method = RequestMethod.POST, produces = "application/json")@PostMapping("/article")public AjaxResponse saveArticle(@RequestBody Article article) {articleRestService.saveArticle(article);retu AjaxResponse.success(article);}}

自定义MockMvc做法，会报出空指针异常

@Slf4j@SpringBootTestpublic class ArticleRestControllerTest {//mock对象private MockMvc mockMvc;//mock对象初始化@BeforeEachpublic void setUp() {mockMvc = MockMvcBuilders.standaloneSetup(new ArticleRestController()).build();}//测试方法@Testpublic void saveArticle() throws Exception {String article = "{\n" +"\"id\": 1,\n" +"\"author\": \"zimug\",\n" +"\"title\": \"手摸手教你开发spring boot\",\n" +"\"content\": \"c\",\n" +"\"reader\":[{\"name\":\"zimug\",\"age\":18},{\"name\":\"kobe\",\"age\":37}]\n" +"}";MvcResult result = mockMvc.perform(MockMvcRequestBuilders.request(HttpMethod.POST, "/rest/article").contentType("application/json").content(article)).andExpect(MockMvcResultMatchers.status().isOk()).andExpect(MockMvcResultMatchers.jsonPath("$.data.author").value("zimug")).andExpect(MockMvcResultMatchers.jsonPath("$.data.reader[0].age").value(18)).andDo(print()).andRetu();log.info(result.getResponse().getContentAsString());}}

使用@RunWith(SpringRunner.class)注解

@Slf4j@RunWith(SpringRunner.class)@AutoConfigureMockMvc//相当于new MockMvc@SpringBootTestpublic class ArticleRestControllerTest2 {//mock对象@Resourceprivate MockMvc mockMvc;@ResourceArticleRestService articleRestService;//测试方法@Testpublic void saveArticle() throws Exception {String article = "{\n" +"\"id\": 1,\n" +"\"author\": \"zimug\",\n" +"\"title\": \"手摸手教你开发spring boot\",\n" +"\"content\": \"c\",\n" +"\"reader\":[{\"name\":\"zimug\",\"age\":18},{\"name\":\"kobe\",\"age\":37}]\n" +"}";MvcResult result = mockMvc.perform(MockMvcRequestBuilders.request(HttpMethod.POST, "/rest/article").contentType("application/json").content(article)).andExpect(MockMvcResultMatchers.status().isOk()).andExpect(MockMvcResultMatchers.jsonPath("$.data.author").value("zimug")).andExpect(MockMvcResultMatchers.jsonPath("$.data.reader[0].age").value(18)).andDo(print()).andRetu();log.info(result.getResponse().getContentAsString());}}

不会报出异常

解析

• RunWith方法为我们构造了一个的Servlet容器运行运行环境，并在此环境下测试。然而为什么要构建servlet容器？因为使用了依赖注入，注入了MockMvc对象，而在上一个例子里面是我们自己new的。
• 而@AutoConfigureMockMvc注解，该注解表示 MockMvc由spring容器构建，你只负责注入之后用就可以了。这种写法是为了让测试在Spring容器环境下执行。
• Spring的容器环境是什么呢？比如常见的 Service、Dao 都是Spring容器里的bean，装载到容器里面都可以使用@Resource和@Autowired来注入引用。
• 简单的说：如果你单元测试代码使用了依赖注入就加上@RunWith，如果你不是手动new MockMvc对象就加上@AutoConfigureMockMvc