java - 使用 @Qualifier 时，依赖注入(inject)在 Spring 测试中失败

Question

我正在使用 JDK 1.7，intelliJ 社区 13，我正在编写 Spring JUnit 测试:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"classpath*:test-applicationContext.xml"})
public class InstructionMessageTest {

    @Autowired
    @Qualifier("validator")
    public Validator validator;

    @Test
    public void shouldFailValidationWithLowInstructionType() throws Exception {
        InstructionMessage underTest = new InstructionMessage(0, 1, 1, 0, 1);
        underTest.getInstructionType();
////        validator.validate(underTest);
//        ApplicationContext tstctx = new ClassPathXmlApplicationContext("test-applicationContrext.xml");
//        Validator validator = (Validator) tstctx.getBean("validator");
//        Set<ConstraintViolation<InstructionMessage>> errors = validator.validate(underTest);
    }

    @Test
    public void shouldFailValidationWithHighInstructiuontype() throws Exception {

    }
}

这是应用程序上下文

    <?xml version="1.0" encoding="UTF-8"?>

<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context-3.1.xsd">

    <context:annotation-config />

    <context:component-scan base-package="org.ian.*" />

    <bean id="validator" class="org.springframework.validation.beanvalidation.LocalValidatorFactoryBean"/>

</beans>

当我尝试运行测试时

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.ian.beer.instructionProcessing.InstructionMessageTest': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: public javax.validation.Validator org.ian.beer.instructionProcessing.InstructionMessageTest.validator; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [javax.validation.Validator] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true), @org.springframework.beans.factory.annotation.Qualifier(value=validator)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:289)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1146)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireBeanProperties(AbstractAutowireCapableBeanFactory.java:376)
    at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:110)
    at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:75)
    at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:312)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:211)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:288)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:284)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:231)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:88)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:174)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:74)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:202)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:65)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)
Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: public javax.validation.Validator org.ian.beer.instructionProcessing.InstructionMessageTest.validator; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [javax.validation.Validator] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true), @org.springframework.beans.factory.annotation.Qualifier(value=validator)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:517)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:286)
    ... 29 more
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [javax.validation.Validator] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true), @org.springframework.beans.factory.annotation.Qualifier(value=validator)}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:988)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:858)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:770)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:489)
    ... 31 more

当我在上下文中取消注释手动查找时，一切正常。我错过了什么吗？

Answer 1

您正在通过注释和代码执行两件不同的事情。通过注释，您可以搜索与接口(interface)和限定符匹配的类。在代码中，您可以使用唯一的 bean 名称进行匹配。

org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [javax.validation.Validator] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency.

这个错误非常明显:您没有声明带有限定符“validator”的 javax.validation.Validator 类型的 bean。你应该这样做:

<bean id="validator" class="org.springframework.validation.beanvalidation.LocalValidatorFactoryBean">
    <qualifier value="validator"/>
</bean>

引用:http://docs.spring.io/spring/docs/3.0.x/spring-framework-reference/html/beans.html

或者作为替代方案，使用带有 javax.annotation.Resource 注释的精确映射:

@javax.annotation.Resource(name="validator")
private Validator validator;

它正在执行您手动执行的操作:

Validator validator = (Validator) tstctx.getBean("validator");