问为什么我得到“加载ApplicationContext失败”Spring，带有JavaConfig的jUnit

EN

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = HelloWorldConfig.class)
public class TestApp
{

    @Test
    public void testBean()
    {
      ApplicationContext context = new AnnotationConfigApplicationContext(HelloWorldConfig.class);

      HelloWorld helloWorld = context.getBean(HelloWorld.class);
      helloWorld.setMessage("I am in Staten Island, New York");

      Assert.assertEquals(helloWorld.getMessage(), "I am in Staten Island, New York");
    }
}

    java.lang.IllegalStateException: Failed to load ApplicationContext  at
org.springframework.test.context.CacheAwareContextLoaderDelegate.loadContext(CacheAwareContextLoaderDelegate.java:99)
    at
org.springframework.test.context.TestContext.getApplicationContext(TestContext.java:122)
    at
org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:109)
    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:15)
    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:193)  at
org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:52)     at
org.junit.runners.ParentRunner.runChildren(ParentRunner.java:191)   at
org.junit.runners.ParentRunner.access$000(ParentRunner.java:42)     at
org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:184)    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:236)    at
org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:174)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:157)   at
com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:77)
    at
com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:195)
    at
com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:63)
    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:
Error creating bean with name 'messageService': Injection of autowired
dependencies failed; nested exception is
org.springframework.beans.factory.BeanCreationException: Could not
autowire field: private
com.johnathanmarksmith.hellospring.dao.MessageDao
com.johnathanmarksmith.hellospring.service.MessageServiceImpl.messageDao;
nested exception is
org.springframework.beans.factory.NoSuchBeanDefinitionException: No
qualifying bean of type
[com.johnathanmarksmith.hellospring.dao.MessageDao] 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)}
    at
org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:288)
    at
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1122)
    at
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:522)
    at
org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:461)
    at
org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:295)
    at
org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:223)
    at
org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:292)
    at
org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:194)
    at
org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:626)
    at
org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:932)
    at
org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:479)
    at
org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:120)
    at
org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:60)
    at
org.springframework.test.context.support.AbstractDelegatingSmartContextLoader.delegateLoading(AbstractDelegatingSmartContextLoader.java:100)
    at
org.springframework.test.context.support.AbstractDelegatingSmartContextLoader.loadContext(AbstractDelegatingSmartContextLoader.java:248)
    at
org.springframework.test.context.CacheAwareContextLoaderDelegate.loadContextInternal(CacheAwareContextLoaderDelegate.java:64)
    at
org.springframework.test.context.CacheAwareContextLoaderDelegate.loadContext(CacheAwareContextLoaderDelegate.java:91)
    ... 28 more Caused by:
org.springframework.beans.factory.BeanCreationException: Could not
autowire field: private
com.johnathanmarksmith.hellospring.dao.MessageDao
com.johnathanmarksmith.hellospring.service.MessageServiceImpl.messageDao;
nested exception is
org.springframework.beans.factory.NoSuchBeanDefinitionException: No
qualifying bean of type
[com.johnathanmarksmith.hellospring.dao.MessageDao] 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)}
    at
org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:514)
    at
org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
    at
org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:285)
    ... 44 more Caused by:
org.springframework.beans.factory.NoSuchBeanDefinitionException: No
qualifying bean of type
[com.johnathanmarksmith.hellospring.dao.MessageDao] 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)}
    at
org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:986)
    at
org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:856)
    at
org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:768)
    at
org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:486)