spring学习15-required属性

CompactDisc类
    package soundSystem;
     import org.springframework.stereotype.Component;
     //注解@Component
     public class CompactDisc {
         public CompactDisc() {
             super();
             System.out.println("compactdisc无参构造方法");
         }
         public void play(){
             System.out.println("正在播放音乐....");
         }
     }CDplay类
    package soundSystem;
     import org.springframework.beans.factory.annotation.Autowired;
     import org.springframework.stereotype.Component;
     @Component
     public class CDPlayer {
         @Autowired(required = false)
         private CompactDisc cd;
         @Autowired
         private Power power;
         public CDPlayer() {
             super();
             System.out.println("CDPlayer无参构造方法");
         }
     /*@Autowired
         public CDPlayer(CompactDisc cd) {
             this.cd = cd;
             System.out.println("CDPlayer有参构造方法");
         }*/
     /*
         public CDPlayer(CompactDisc cd, Power power) {
             this.cd = cd;
             this.power = power;
             System.out.println("CDplayer的参数配置");
         }
         */
         public void play(){
             power.supply();
             if(cd!=null) {
                 cd.play();
             }
         }
     }appconfig类
    package soundSystem;
     import org.springframework.context.annotation.ComponentScan;
     //spring注解类
     @ComponentScan
     public class Appconfig {
     }power类
    package soundSystem;
     import org.springframework.stereotype.Component;
     @Component
     public class Power {
         public Power() {
             super();
         }
         public void supply(){
             System.out.println("电源宫殿中..");
         }
     }apptest类
    package soundSystem;
     import org.junit.Test;
     import org.junit.runner.RunWith;
     import org.springframework.beans.factory.annotation.Autowired;
     import org.springframework.context.ApplicationContext;
     import org.springframework.context.annotation.AnnotationConfigApplicationContext;
     import org.springframework.test.context.ContextConfiguration;
     import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
     //@RunWith(SpringJunit4ClassRunner.class)
     //@ContextConfiguration(class=)
     @RunWith(SpringJUnit4ClassRunner.class)
     @ContextConfiguration(classes = Appconfig.class)
     public class AppTest {
         @Autowired
         private CDPlayer player;
         @Test
         public void testPlay(){
            player.play();
         }
     }运行结果
    [INFO ] 2019-10-30 18:42:32,195 method:org.springframework.test.context.support.AbstractTestContextBootstrapper.getDefaultTestExecutionListenerClassNames(AbstractTestContextBootstrapper.java:260)
     Loaded default TestExecutionListener class names from location [META-INF/spring.factories]: [org.springframework.test.context.web.ServletTestExecutionListener, org.springframework.test.context.support.DirtiesContextBeforeModesTestExecutionListener, org.springframework.test.context.support.DependencyInjectionTestExecutionListener, org.springframework.test.context.support.DirtiesContextTestExecutionListener, org.springframework.test.context.transaction.TransactionalTestExecutionListener, org.springframework.test.context.jdbc.SqlScriptsTestExecutionListener]
     [INFO ] 2019-10-30 18:42:32,203 method:org.springframework.test.context.support.AbstractTestContextBootstrapper.instantiateListeners(AbstractTestContextBootstrapper.java:209)
     Could not instantiate TestExecutionListener [org.springframework.test.context.web.ServletTestExecutionListener]. Specify custom listener classes or make the default listener classes (and their required dependencies) available. Offending class: [javax/servlet/ServletContext]
     [INFO ] 2019-10-30 18:42:32,205 method:org.springframework.test.context.support.AbstractTestContextBootstrapper.instantiateListeners(AbstractTestContextBootstrapper.java:209)
     Could not instantiate TestExecutionListener [org.springframework.test.context.jdbc.SqlScriptsTestExecutionListener]. Specify custom listener classes or make the default listener classes (and their required dependencies) available. Offending class: [org/springframework/transaction/interceptor/TransactionAttribute]
     [INFO ] 2019-10-30 18:42:32,206 method:org.springframework.test.context.support.AbstractTestContextBootstrapper.instantiateListeners(AbstractTestContextBootstrapper.java:209)
     Could not instantiate TestExecutionListener [org.springframework.test.context.transaction.TransactionalTestExecutionListener]. Specify custom listener classes or make the default listener classes (and their required dependencies) available. Offending class: [org/springframework/transaction/interceptor/TransactionAttributeSource]
     [INFO ] 2019-10-30 18:42:32,208 method:org.springframework.test.context.support.AbstractTestContextBootstrapper.getTestExecutionListeners(AbstractTestContextBootstrapper.java:187)
     Using TestExecutionListeners: [org.springframework.test.context.support.DirtiesContextBeforeModesTestExecutionListener@1786f9d5, org.springframework.test.context.support.DependencyInjectionTestExecutionListener@704d6e83, org.springframework.test.context.support.DirtiesContextTestExecutionListener@43a0cee9][INFO ] 2019-10-30 18:42:32,393 method:org.springframework.context.support.AbstractApplicationContext.prepareRefresh(AbstractApplicationContext.java:583)
     Refreshing org.springframework.context.support.GenericApplicationContext@4df828d7: startup date [Wed Oct 30 18:42:32 CST 2019]; root of context hierarchy
     [DEBUG] 2019-10-30 18:42:32,427 method:org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:221)
     Creating shared instance of singleton bean 'org.springframework.context.annotation.internalConfigurationAnnotationProcessor'
     [DEBUG] 2019-10-30 18:42:32,427 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:449)
     Creating instance of bean 'org.springframework.context.annotation.internalConfigurationAnnotationProcessor'
     [DEBUG] 2019-10-30 18:42:32,454 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:539)
     Eagerly caching bean 'org.springframework.context.annotation.internalConfigurationAnnotationProcessor' to allow for resolving potential circular references
     [DEBUG] 2019-10-30 18:42:32,458 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:485)
     Finished creating instance of bean 'org.springframework.context.annotation.internalConfigurationAnnotationProcessor'
     [DEBUG] 2019-10-30 18:42:32,557 method:org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:221)
     Creating shared instance of singleton bean 'org.springframework.context.annotation.internalAutowiredAnnotationProcessor'
     [DEBUG] 2019-10-30 18:42:32,557 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:449)
     Creating instance of bean 'org.springframework.context.annotation.internalAutowiredAnnotationProcessor'
     [DEBUG] 2019-10-30 18:42:32,559 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:539)
     Eagerly caching bean 'org.springframework.context.annotation.internalAutowiredAnnotationProcessor' to allow for resolving potential circular references
     [DEBUG] 2019-10-30 18:42:32,590 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:485)
     Finished creating instance of bean 'org.springframework.context.annotation.internalAutowiredAnnotationProcessor'
     [DEBUG] 2019-10-30 18:42:32,591 method:org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:221)
     Creating shared instance of singleton bean 'org.springframework.context.annotation.internalRequiredAnnotationProcessor'
     [DEBUG] 2019-10-30 18:42:32,591 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:449)
     Creating instance of bean 'org.springframework.context.annotation.internalRequiredAnnotationProcessor'
     [DEBUG] 2019-10-30 18:42:32,593 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:539)
     Eagerly caching bean 'org.springframework.context.annotation.internalRequiredAnnotationProcessor' to allow for resolving potential circular references
     [DEBUG] 2019-10-30 18:42:32,599 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:485)
     Finished creating instance of bean 'org.springframework.context.annotation.internalRequiredAnnotationProcessor'
     [DEBUG] 2019-10-30 18:42:32,606 method:org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:730)
     Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@158da8e: defining beans [org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.event.internalEventListenerProcessor,org.springframework.context.event.internalEventListenerFactory,appconfig,CDPlayer,power]; root of factory hierarchy
     [DEBUG] 2019-10-30 18:42:32,606 method:org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:251)
     Returning cached instance of singleton bean 'org.springframework.context.annotation.internalConfigurationAnnotationProcessor'
     [DEBUG] 2019-10-30 18:42:32,606 method:org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:251)
     Returning cached instance of singleton bean 'org.springframework.context.annotation.internalAutowiredAnnotationProcessor'
     [DEBUG] 2019-10-30 18:42:32,607 method:org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:251)
     Returning cached instance of singleton bean 'org.springframework.context.annotation.internalRequiredAnnotationProcessor'
     [DEBUG] 2019-10-30 18:42:32,607 method:org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:221)
     Creating shared instance of singleton bean 'org.springframework.context.event.internalEventListenerProcessor'
     [DEBUG] 2019-10-30 18:42:32,607 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:449)
     Creating instance of bean 'org.springframework.context.event.internalEventListenerProcessor'
     [DEBUG] 2019-10-30 18:42:32,613 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:539)
     Eagerly caching bean 'org.springframework.context.event.internalEventListenerProcessor' to allow for resolving potential circular references
     [DEBUG] 2019-10-30 18:42:32,618 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:485)
     Finished creating instance of bean 'org.springframework.context.event.internalEventListenerProcessor'
     [DEBUG] 2019-10-30 18:42:32,619 method:org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:221)
     Creating shared instance of singleton bean 'org.springframework.context.event.internalEventListenerFactory'
     [DEBUG] 2019-10-30 18:42:32,619 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:449)
     Creating instance of bean 'org.springframework.context.event.internalEventListenerFactory'
     [DEBUG] 2019-10-30 18:42:32,620 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:539)
     Eagerly caching bean 'org.springframework.context.event.internalEventListenerFactory' to allow for resolving potential circular references
     [DEBUG] 2019-10-30 18:42:32,623 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:485)
     Finished creating instance of bean 'org.springframework.context.event.internalEventListenerFactory'
     [DEBUG] 2019-10-30 18:42:32,624 method:org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:221)
     Creating shared instance of singleton bean 'appconfig'
     [DEBUG] 2019-10-30 18:42:32,625 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:449)
     Creating instance of bean 'appconfig'
     [DEBUG] 2019-10-30 18:42:32,626 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:539)
     Eagerly caching bean 'appconfig' to allow for resolving potential circular references
     [DEBUG] 2019-10-30 18:42:32,628 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:485)
     Finished creating instance of bean 'appconfig'
     [DEBUG] 2019-10-30 18:42:32,629 method:org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:221)
     Creating shared instance of singleton bean 'CDPlayer'
     [DEBUG] 2019-10-30 18:42:32,629 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:449)
     Creating instance of bean 'CDPlayer'
     CDPlayer无参构造方法
     [DEBUG] 2019-10-30 18:42:32,634 method:org.springframework.beans.factory.annotation.InjectionMetadata.checkConfigMembers(InjectionMetadata.java:72)
     Registered injected element on class [soundSystem.CDPlayer]: AutowiredFieldElement for private soundSystem.CompactDisc soundSystem.CDPlayer.cd
     [DEBUG] 2019-10-30 18:42:32,634 method:org.springframework.beans.factory.annotation.InjectionMetadata.checkConfigMembers(InjectionMetadata.java:72)
     Registered injected element on class [soundSystem.CDPlayer]: AutowiredFieldElement for private soundSystem.Power soundSystem.CDPlayer.power
     [DEBUG] 2019-10-30 18:42:32,634 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:539)
     Eagerly caching bean 'CDPlayer' to allow for resolving potential circular references
     [DEBUG] 2019-10-30 18:42:32,638 method:org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:86)
     Processing injected element of bean 'CDPlayer': AutowiredFieldElement for private soundSystem.CompactDisc soundSystem.CDPlayer.cd
     [DEBUG] 2019-10-30 18:42:32,648 method:org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:86)
     Processing injected element of bean 'CDPlayer': AutowiredFieldElement for private soundSystem.Power soundSystem.CDPlayer.power
     [DEBUG] 2019-10-30 18:42:32,653 method:org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:221)
     Creating shared instance of singleton bean 'power'
     [DEBUG] 2019-10-30 18:42:32,654 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:449)
     Creating instance of bean 'power'
     [DEBUG] 2019-10-30 18:42:32,655 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:539)
     Eagerly caching bean 'power' to allow for resolving potential circular references
     [DEBUG] 2019-10-30 18:42:32,658 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:485)
     Finished creating instance of bean 'power'
     [DEBUG] 2019-10-30 18:42:32,658 method:org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.registerDependentBeans(AutowiredAnnotationBeanPostProcessor.java:535)
     Autowiring by type from bean name 'CDPlayer' to bean named 'power'
     [DEBUG] 2019-10-30 18:42:32,660 method:org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:485)
     Finished creating instance of bean 'CDPlayer'
     [DEBUG] 2019-10-30 18:42:32,661 method:org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:251)
     Returning cached instance of singleton bean 'power'
     [DEBUG] 2019-10-30 18:42:32,662 method:org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:251)
     Returning cached instance of singleton bean 'org.springframework.context.event.internalEventListenerFactory'
     [DEBUG] 2019-10-30 18:42:32,762 method:org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:251)
     Returning cached instance of singleton bean 'lifecycleProcessor'
     [DEBUG] 2019-10-30 18:42:32,772 method:org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:86)
     Processing injected element of bean 'soundSystem.AppTest': AutowiredFieldElement for private soundSystem.CDPlayer soundSystem.AppTest.player
     [DEBUG] 2019-10-30 18:42:32,773 method:org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:251)
     Returning cached instance of singleton bean 'CDPlayer'
     [DEBUG] 2019-10-30 18:42:32,774 method:org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.registerDependentBeans(AutowiredAnnotationBeanPostProcessor.java:535)
     Autowiring by type from bean name 'soundSystem.AppTest' to bean named 'CDPlayer'
     电源宫殿中..
     [INFO ] 2019-10-30 18:42:32,783 method:org.springframework.context.support.AbstractApplicationContext.doClose(AbstractApplicationContext.java:984)
     Closing org.springframework.context.support.GenericApplicationContext@4df828d7: startup date [Wed Oct 30 18:42:32 CST 2019]; root of context hierarchy
     [DEBUG] 2019-10-30 18:42:32,785 method:org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:251)
     Returning cached instance of singleton bean 'lifecycleProcessor'
     [DEBUG] 2019-10-30 18:42:32,786 method:org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.destroySingletons(DefaultSingletonBeanRegistry.java:512)
     Destroying singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@158da8e: defining beans [org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.event.internalEventListenerProcessor,org.springframework.context.event.internalEventListenerFactory,appconfig,CDPlayer,power]; root of factory hierarchy