Springboot junit 测试中出现不满足的依赖异常

Question

我正在使用 spring-boot 1.5.9。我创建了一个简单的 spring-boot 应用程序，它具有以下目录结构。

LibraryService.java自动装配存储库接口并具有将书籍保存到图书馆的方法。

图书馆服务.java

@Service
public class LibraryService  {
  private static final Logger logger = LoggerFactory.getLogger(LibraryService.class);       

  @Autowired
  BookRepository bookRepository;

  public void save(Book book){
    bookRepository.save(book);  
  } 

  public long count(){
    return bookRepository.count();
  }
}

下面是BookRepository界面

public interface BookRepository extends MongoRepository<Book, String> { }

当我在测试类中自动装配时LibraryService，我发现它没有正确注入，并且出现了不满意的依赖异常。以下是 LibraryServiceTest 类

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest
@DataMongoTest
public class LibraryServiceTest {

  @Autowired
  LibraryService libraryService;
    
  @Test
  public void testSave(){
    Book aBook = new Book("Harry Potter", "J. K. Rowling");
    libraryService.save(aBook); 
    assertEquals(1, libraryService.count());;
  } 
}

我在测试类中尝试了@MockBean代替@Autowired，没有例外，但是存储库实例被评估为 null，这导致测试失败。使用junit时注入依赖的正确方法是什么？

编辑

以下是堆栈跟踪：

2017-12-31 09:48:00.112 ERROR 57648 --- [           main] 
o.s.test.context.TestContextManager      : Caught exception while allowing 
TestExecutionListener
[org.springframework.boot.test.autoconfigure.SpringBootDependencyInjectionTestExecutionListener@32464a14] to prepare test instance [com.example.demo.service.LibraryServiceTest@56193c7d]

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'com.example.demo.service.LibraryServiceTest': Unsatisfied dependency expressed through field 'libraryService'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.example.demo.service.LibraryService' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:588) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:366) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1264) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireBeanProperties(AbstractAutowireCapableBeanFactory.java:386) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:118) ~[spring-test-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:83) ~[spring-test-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.boot.test.autoconfigure.SpringBootDependencyInjectionTestExecutionListener.prepareTestInstance(SpringBootDependencyInjectionTestExecutionListener.java:44) ~[spring-boot-test-autoconfigure-1.5.9.RELEASE.jar:1.5.9.RELEASE]
at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:230) ~[spring-test-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:228) [spring-test-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:287) [spring-test-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) [junit-4.12.jar:4.12]
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:289) [spring-test-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:247) [spring-test-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:94) [spring-test-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290) [junit-4.12.jar:4.12]
at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71) [junit-4.12.jar:4.12]
at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288) [junit-4.12.jar:4.12]
at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58) [junit-4.12.jar:4.12]
at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268) [junit-4.12.jar:4.12]
at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61) [spring-test-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:70) [spring-test-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.junit.runners.ParentRunner.run(ParentRunner.java:363) [junit-4.12.jar:4.12]
at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:191) [spring-test-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86) [.cp/:na]
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) [.cp/:na]
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459) [.cp/:na]
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:675) [.cp/:na]
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382) [.cp/:na]
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192) [.cp/:na]
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.example.demo.service.LibraryService' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1493) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1104) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:585) ~[spring-beans-4.3.13.RELEASE.jar:4.3.13.RELEASE]
... 29 common frames omitted

Answer 1

从文档中：

@RunWith(SpringRunner.class)可与典型 MongoDB 测试结合使用的注释。当测试仅关注 MongoDB 组件时可以使用。

使用此注释将禁用完全自动配置，而仅应用与 MongoDB 测试相关的配置。

因此，这会将您的服务从 spring 上下文中排除（并且无论如何都应该使用它进行注释@RunWith(SpringRunner.class)）。

用它来测试您的 Mongo 存储库。要测试您的服务，请模拟存储库（这就是 DI 首先有用的原因），并在模拟存储库上测试服务内的业务逻辑。