为什么组件扫描不适用于 Spring 引导单元测试？
Why component scanning does not work for Spring Boot unit tests?
服务 class FooServiceImpl 被注释为 @Service 又名 @Component 这使得它符合自动装配的条件。为什么这个 class 在单元测试期间没有被拾取和自动装配？
@Service
public class FooServiceImpl implements FooService {
@Override
public String reverse(String bar) {
return new StringBuilder(bar).reverse().toString();
}
}
@RunWith(SpringRunner.class)
//@SpringBootTest
public class FooServiceTest {
@Autowired
private FooService fooService;
@Test
public void reverseStringShouldReverseAnyString() {
String reverse = fooService.reverse("hello");
assertThat(reverse).isEqualTo("olleh");
}
}
测试未能加载应用程序上下文，
2018-02-08T10:58:42,385 INFO Neither @ContextConfiguration nor @ContextHierarchy found for test class [io.github.thenilesh.service.impl.FooServiceTest], using DelegatingSmartContextLoader
2018-02-08T10:58:42,393 INFO Could not detect default resource locations for test class [io.github.thenilesh.service.impl.FooServiceTest]: no resource found for suffixes {-context.xml}.
2018-02-08T10:58:42,394 INFO Could not detect default configuration classes for test class [io.github.thenilesh.service.impl.FooServiceTest]: FooServiceTest does not declare any static, non-private, non-final, nested classes annotated with @Configuration.
2018-02-08T10:58:42,432 INFO Loaded default TestExecutionListener class names from location [META-INF/spring.factories]: [org.springframework.boot.test.mock.mockito.MockitoTestExecutionListener, org.springframework.boot.test.mock.mockito.ResetMocksTestExecutionListener, org.springframework.boot.test.autoconfigure.restdocs.RestDocsTestExecutionListener, (...)org.springframework.test.context.transaction.TransactionalTestExecutionListener, org.springframework.test.context.jdbc.SqlScriptsTestExecutionListener]
2018-02-08T10:58:42,448 INFO Using TestExecutionListeners: [org.springframework.test.context.web.ServletTestExecutionListener@f0ea28, org.springframework.test.context.support.DirtiesContextBeforeModesTestExecutionListener@16efaab,(...)org.springframework.boot.test.autoconfigure.web.servlet.MockMvcPrintOnlyOnFailureTestExecutionListener@9604d9]
2018-02-08T10:58:42,521 INFO Refreshing org.springframework.context.support.GenericApplicationContext@173f9fc: startup date [Thu Feb 08 10:58:42 IST 2018]; root of context hierarchy
2018-02-08T10:58:42,606 INFO JSR-330 'javax.inject.Inject' annotation found and supported for autowiring
2018-02-08T10:58:42,666 ERROR Caught exception while allowing TestExecutionListener [org.springframework.test.context.support.DependencyInjectionTestExecutionListener@19aaa5] to prepare test instance [io.github.thenilesh.service.impl.FooServiceTest@57f43]
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'io.github.thenilesh.service.impl.FooServiceTest': Unsatisfied dependency expressed through field 'fooService'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'io.github.thenilesh.service.FooService' 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.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192) [.cp/:?]
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'io.github.thenilesh.service.FooService' 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]
... 28 more
2018-02-08T10:58:42,698 INFO Closing org.springframework.context.support.GenericApplicationContext@173f9fc: startup date [Thu Feb 08 10:58:42 IST 2018]; root of context hierarchy
如果测试 class 用 @SpringBootTest 注释，那么它会创建整个应用程序上下文，包括数据库连接和许多不相关的 bean，显然这个单元测试不需要（它不会是 unit 然后测试！）。预期的是只有 FooService 依赖的 beans 应该被实例化，除了被模拟的 beans，@MockBean.
单元测试应该单独测试一个组件。您甚至不需要使用 Spring 测试上下文框架进行单元测试。您可以使用 Mockito、JMock 或 EasyMock 等模拟框架来隔离组件中的依赖项并验证预期。
如果您想要真正的集成测试，那么您需要在测试中使用@SpringBootTest 注释class。如果您不指定 classes 属性，它会加载带注释的 @SpringBootApplication class。这会导致加载数据库连接等生产组件。
要消除这些，请定义一个单独的测试配置 class，例如定义一个嵌入式数据库而不是生产数据库
@SpringBootTest(classes = TestConfiguration.class)
public class ServiceFooTest{
}
@Configuration
@Import(SomeProductionConfiguration.class)
public class TestConfiguration{
//test specific components
}
你应该使用 @SpringBootTest(classes=FooServiceImpl.class).
如Annotation Type SpringBootTest所述：
public abstract Class<?>[] classes
The annotated classes to use for loading an ApplicationContext. Can
also be specified using @ContextConfiguration(classes=...). If no
explicit classes are defined the test will look for nested
@Configuration classes, before falling back to a
SpringBootConfiguration search.
Returns:
the annotated classes used to load the application context See Also:
ContextConfiguration.classes()
Default:
{}
这只会加载必要的 class。如果不指定，它可能会加载数据库配置和其他会使您的测试变慢的东西。
另一方面，如果你真的想要单元测试，你可以在没有 Spring 的情况下测试这段代码 - 那么 @RunWith(SpringRunner.class) 和 @SpringBootTest 注释就不是必需的了。您可以测试 FooServiceImpl 个实例。如果您有 Autowired/注入的属性或服务，您可以通过设置器、构造函数或使用 Mockito.
模拟来设置它们
我不得不解决一个类似的问题，但稍有不同。想把它的细节分享出来，认为它可能会给遇到类似问题的人提供选择。
我想编写集成测试，只加载必要的依赖项，而不是加载所有应用程序依赖项。所以我选择使用@DataJpaTest，而不是@SpringBootTest。而且，我还必须包含 @ComponentScan 来解析 @Service bean。然而，当 ServiceOne 开始使用来自另一个包的映射器 bean 时，我必须指定要加载的特定包 @ComponentScan。令人惊讶的是，我什至不得不为不自动连接此映射器的第二个服务执行此操作。我不喜欢这样，因为它给 reader 留下了这样的印象，即该服务依赖于该映射器，而实际上它并不依赖该映射器。所以我意识到服务的包结构需要进一步微调以更准确地表示依赖关系。
总而言之，@DataJpaTest+@ComponentScan 与包名称的组合可以用来加载特定于层的依赖项，而不是@SpringBootTest。这甚至可以帮助我们微调设计以更准确地表示您的依赖关系。
之前设计
1. com.java.service.ServiceOneImpl
@Service
public class ServiceOneImpl implements ServiceOne {
@Autowired
private RepositoryOne repositoryOne;
@Autowired
private ServiceTwo serviceTwo;
@Autowired
private MapperOne mapperOne;
}
2。 com.java.service.ServiceTwoImpl
@Service
public class ServiceTwoImpl implements ServiceTwo {
@Autowired
private RepositoryTwo repositoryTwo;
}
3。 ServiceOneIntegrationTest
@RunWith(SpringRunner.class)
@DataJpaTest
@ComponentScan({"com.java.service","com.java.mapper"})
public class ServiceOneIntegrationTest {
4。 ServiceTwoIntegrationTest.java
@RunWith(SpringRunner.class)
@DataJpaTest
@ComponentScan({"com.java.service","com.java.mapper"})
public class ServiceTwoIntegrationTest {
微调包名称后
1. com.java.service.one.ServiceOneImpl
@Service
public class ServiceOneImpl implements ServiceOne {
@Autowired
private RepositoryOne repositoryOne;
@Autowired
private ServiceTwo serviceTwo;
@Autowired
private MapperOne mapperOne;
}
2。 com.java.service.two.ServiceTwoImpl
@Service
public class ServiceTwoImpl implements ServiceTwo {
@Autowired
private RepositoryTwo repositoryTwo;
}
3。 ServiceOneIntegrationTest
@RunWith(SpringRunner.class)
@DataJpaTest
@ComponentScan({"com.java.service","com.java.mapper"})
public class ServiceOneIntegrationTest {
4。 ServiceTwoIntegrationTest.java
@RunWith(SpringRunner.class)
@DataJpaTest
@ComponentScan({"com.java.service.two"}) // CHANGE in the packages
public class ServiceTwoIntegrationTest {
服务 class FooServiceImpl 被注释为 @Service 又名 @Component 这使得它符合自动装配的条件。为什么这个 class 在单元测试期间没有被拾取和自动装配？
@Service
public class FooServiceImpl implements FooService {
@Override
public String reverse(String bar) {
return new StringBuilder(bar).reverse().toString();
}
}
@RunWith(SpringRunner.class)
//@SpringBootTest
public class FooServiceTest {
@Autowired
private FooService fooService;
@Test
public void reverseStringShouldReverseAnyString() {
String reverse = fooService.reverse("hello");
assertThat(reverse).isEqualTo("olleh");
}
}
测试未能加载应用程序上下文，
2018-02-08T10:58:42,385 INFO Neither @ContextConfiguration nor @ContextHierarchy found for test class [io.github.thenilesh.service.impl.FooServiceTest], using DelegatingSmartContextLoader
2018-02-08T10:58:42,393 INFO Could not detect default resource locations for test class [io.github.thenilesh.service.impl.FooServiceTest]: no resource found for suffixes {-context.xml}.
2018-02-08T10:58:42,394 INFO Could not detect default configuration classes for test class [io.github.thenilesh.service.impl.FooServiceTest]: FooServiceTest does not declare any static, non-private, non-final, nested classes annotated with @Configuration.
2018-02-08T10:58:42,432 INFO Loaded default TestExecutionListener class names from location [META-INF/spring.factories]: [org.springframework.boot.test.mock.mockito.MockitoTestExecutionListener, org.springframework.boot.test.mock.mockito.ResetMocksTestExecutionListener, org.springframework.boot.test.autoconfigure.restdocs.RestDocsTestExecutionListener, (...)org.springframework.test.context.transaction.TransactionalTestExecutionListener, org.springframework.test.context.jdbc.SqlScriptsTestExecutionListener]
2018-02-08T10:58:42,448 INFO Using TestExecutionListeners: [org.springframework.test.context.web.ServletTestExecutionListener@f0ea28, org.springframework.test.context.support.DirtiesContextBeforeModesTestExecutionListener@16efaab,(...)org.springframework.boot.test.autoconfigure.web.servlet.MockMvcPrintOnlyOnFailureTestExecutionListener@9604d9]
2018-02-08T10:58:42,521 INFO Refreshing org.springframework.context.support.GenericApplicationContext@173f9fc: startup date [Thu Feb 08 10:58:42 IST 2018]; root of context hierarchy
2018-02-08T10:58:42,606 INFO JSR-330 'javax.inject.Inject' annotation found and supported for autowiring
2018-02-08T10:58:42,666 ERROR Caught exception while allowing TestExecutionListener [org.springframework.test.context.support.DependencyInjectionTestExecutionListener@19aaa5] to prepare test instance [io.github.thenilesh.service.impl.FooServiceTest@57f43]
org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'io.github.thenilesh.service.impl.FooServiceTest': Unsatisfied dependency expressed through field 'fooService'; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'io.github.thenilesh.service.FooService' 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.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192) [.cp/:?]
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'io.github.thenilesh.service.FooService' 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]
... 28 more
2018-02-08T10:58:42,698 INFO Closing org.springframework.context.support.GenericApplicationContext@173f9fc: startup date [Thu Feb 08 10:58:42 IST 2018]; root of context hierarchy
如果测试 class 用 @SpringBootTest 注释，那么它会创建整个应用程序上下文，包括数据库连接和许多不相关的 bean，显然这个单元测试不需要（它不会是 unit 然后测试！）。预期的是只有 FooService 依赖的 beans 应该被实例化，除了被模拟的 beans，@MockBean.
单元测试应该单独测试一个组件。您甚至不需要使用 Spring 测试上下文框架进行单元测试。您可以使用 Mockito、JMock 或 EasyMock 等模拟框架来隔离组件中的依赖项并验证预期。
如果您想要真正的集成测试，那么您需要在测试中使用@SpringBootTest 注释class。如果您不指定 classes 属性，它会加载带注释的 @SpringBootApplication class。这会导致加载数据库连接等生产组件。
要消除这些，请定义一个单独的测试配置 class，例如定义一个嵌入式数据库而不是生产数据库
@SpringBootTest(classes = TestConfiguration.class)
public class ServiceFooTest{
}
@Configuration
@Import(SomeProductionConfiguration.class)
public class TestConfiguration{
//test specific components
}
你应该使用 @SpringBootTest(classes=FooServiceImpl.class).
如Annotation Type SpringBootTest所述：
public abstract Class<?>[] classes
The annotated classes to use for loading an ApplicationContext. Can also be specified using @ContextConfiguration(classes=...). If no explicit classes are defined the test will look for nested @Configuration classes, before falling back to a SpringBootConfiguration search.
Returns: the annotated classes used to load the application context See Also: ContextConfiguration.classes()
Default: {}
这只会加载必要的 class。如果不指定，它可能会加载数据库配置和其他会使您的测试变慢的东西。
另一方面，如果你真的想要单元测试，你可以在没有 Spring 的情况下测试这段代码 - 那么 @RunWith(SpringRunner.class) 和 @SpringBootTest 注释就不是必需的了。您可以测试 FooServiceImpl 个实例。如果您有 Autowired/注入的属性或服务，您可以通过设置器、构造函数或使用 Mockito.
我不得不解决一个类似的问题，但稍有不同。想把它的细节分享出来，认为它可能会给遇到类似问题的人提供选择。
我想编写集成测试，只加载必要的依赖项，而不是加载所有应用程序依赖项。所以我选择使用@DataJpaTest，而不是@SpringBootTest。而且，我还必须包含 @ComponentScan 来解析 @Service bean。然而，当 ServiceOne 开始使用来自另一个包的映射器 bean 时，我必须指定要加载的特定包 @ComponentScan。令人惊讶的是，我什至不得不为不自动连接此映射器的第二个服务执行此操作。我不喜欢这样，因为它给 reader 留下了这样的印象，即该服务依赖于该映射器，而实际上它并不依赖该映射器。所以我意识到服务的包结构需要进一步微调以更准确地表示依赖关系。
总而言之，@DataJpaTest+@ComponentScan 与包名称的组合可以用来加载特定于层的依赖项，而不是@SpringBootTest。这甚至可以帮助我们微调设计以更准确地表示您的依赖关系。
之前设计
1. com.java.service.ServiceOneImpl
@Service
public class ServiceOneImpl implements ServiceOne {
@Autowired
private RepositoryOne repositoryOne;
@Autowired
private ServiceTwo serviceTwo;
@Autowired
private MapperOne mapperOne;
}
2。 com.java.service.ServiceTwoImpl
@Service
public class ServiceTwoImpl implements ServiceTwo {
@Autowired
private RepositoryTwo repositoryTwo;
}
3。 ServiceOneIntegrationTest
@RunWith(SpringRunner.class)
@DataJpaTest
@ComponentScan({"com.java.service","com.java.mapper"})
public class ServiceOneIntegrationTest {
4。 ServiceTwoIntegrationTest.java
@RunWith(SpringRunner.class)
@DataJpaTest
@ComponentScan({"com.java.service","com.java.mapper"})
public class ServiceTwoIntegrationTest {
微调包名称后
1. com.java.service.one.ServiceOneImpl
@Service
public class ServiceOneImpl implements ServiceOne {
@Autowired
private RepositoryOne repositoryOne;
@Autowired
private ServiceTwo serviceTwo;
@Autowired
private MapperOne mapperOne;
}
2。 com.java.service.two.ServiceTwoImpl
@Service
public class ServiceTwoImpl implements ServiceTwo {
@Autowired
private RepositoryTwo repositoryTwo;
}
3。 ServiceOneIntegrationTest
@RunWith(SpringRunner.class)
@DataJpaTest
@ComponentScan({"com.java.service","com.java.mapper"})
public class ServiceOneIntegrationTest {
4。 ServiceTwoIntegrationTest.java
@RunWith(SpringRunner.class)
@DataJpaTest
@ComponentScan({"com.java.service.two"}) // CHANGE in the packages
public class ServiceTwoIntegrationTest {