Java 弹簧启动单元测试自动连线

我有以下课程：

应用程序和配置类

package mypackage.service;

import mypackage.service.util.MyUtility;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Bean;

@SpringBootApplication
public class ApplicationAndConfiguration {


    public static void main(String[] args) {
        ApplicationContext context = SpringApplication.run(ApplicationAndConfiguration.class, new String[]{});
    }

    @Bean(initMethod="init")
    public MyUtility birtUtil() {
        return new MyUtility();
    }
}

MyRestController类

package mypackage.service.controllers;

import mypackage.service.util.MyUtility;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class MyRestController {

    @Autowired
    private MyUtility util;

    @RequestMapping("/getLibraryName")
    public String getMessageFromRest(@RequestParam String name) {

        return "name was " + name + "//" + util.getMessage();
    }   
}

package mypackage.service.util;

public class MyUtility {

    private String message;

    public void init() {
        setMessage("MyUtility correctly initialized!");
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }
}

MyUtility类

package mypackage.service.controllers;

import mypackage.service.util.MyUtility;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class MyRestController {

    @Autowired
    private MyUtility util;

    @RequestMapping("/getLibraryName")
    public String getMessageFromRest(@RequestParam String name) {

        return "name was " + name + "//" + util.getMessage();
    }   
}

package mypackage.service.util;

public class MyUtility {

    private String message;

    public void init() {
        setMessage("MyUtility correctly initialized!");
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }
}

当我启动应用程序并将其作为独立jar运行时，或者从IDE（Eclipse）运行时，一点问题都没有，一切正常

然而，我想写一个单元测试来测试我的MyRestController类。。。我得到一个NPE，因为自动连接字段util为null（在MyRestController类中）

这是我的测试课：

package mypackage.service.controllers;

import static org.hamcrest.Matchers.equalTo;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.content;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
import mypackage.service.ApplicationAndConfiguration;

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.SpringApplicationConfiguration;
import org.springframework.http.MediaType;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.test.context.web.WebAppConfiguration;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;

@SpringApplicationConfiguration(classes = ApplicationAndConfiguration.class)
@WebAppConfiguration
@RunWith(SpringJUnit4ClassRunner.class)
public class TestController {

    private MockMvc mvc;

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

    @Test
    public void MyTestController() throws Exception {

        mvc.perform(MockMvcRequestBuilders.get("/getLibraryName").param("name", "test").accept(MediaType.APPLICATION_JSON))
        .andExpect(status().isOk())
        .andExpect(content().string(equalTo("name was test//MyUtility correctly initialized!")));
    }
}

我肯定错过了一些东西，所以我的自动连线字段在测试期间被填充，而不仅仅是在标准应用程序执行期间

---

任何一个指针，为什么它不工作？

MockMvc独立设置用于单元测试。在测试中创建Spring上下文时，您正在进行集成测试。不要将这两种测试混用

所以就这样改变吧：

@SpringApplicationConfiguration(classes = ApplicationAndConfiguration.class)
@WebAppConfiguration
@RunWith(SpringJUnit4ClassRunner.class)
public class TestController {

    private MockMvc mvc;

    @Autowired
    private WebApplicationContext webApplicationContext;

    @Before
    public void setup() throws Exception {
        mvc = MockMvcBuilders.webAppContextSetup(webApplicationContext).build();
    }

---

自SpringBoot 1.4以来，所有的类都发生了变化并被弃用。将流道和配置替换为以下配置。SpringRunner将为您检测测试框架

@RunWith(SpringRunner.class)
@SpringBootTest(classes = { FileService.class, AppProperties.class, DownloadConfigEventHandler.class })
@EnableConfigurationProperties
public class ConfigMatrixDownloadAndProcessingIntegrationTests extends ConfigMatrixDownloadAbstractTest {

  // @Service FileService
  @Autowired
  private FileService fileService;

  // @Configuration AppProperties
  @Autowired
  private AppProperties properties;

  // @Compoenet DownloadConfigEventHandler
  @Autowired
  private DownloadConfigEventHandler downloadConfigEventHandler;    
  ..
  ..
}

---

所有这些实例都将按预期自动连接！甚至发布服务器上的Spring事件也如中所预期的那样工作。

请注意，使用构造函数注入而不是字段注入将有助于识别此类问题，并使独立单元测试更容易。即使没有classes参数，它也能为我工作。感谢

@RunWith

仅适用于JUnit4，对于JUnit5，请使用

@extendedwith（SpringExtension.class）

。