问题
Hope the Question is self explanatory
ClassA.java
@Component
@Scope(ConfigurableBeanFactory.SCOPE_PROTOTYPE)
public class ClassA implements InterB {
private static int counter=0;
private int objectid = 0;
@Autowired
InterA abcd;
public ClassA() {
super();
this.objectid = ++counter;
}
@Override
public void dododo() {
System.out.println("instance number "+objectid++);
abcd.doit();
}
}
ClassB.java
@Component
@Conditional(OracleDBEngineCondition.class)
public class ClassB extends DummyParent implements InterA {
@Autowired
private Environment env;
@Override
public void doit() {
System.out.println("hoo hoo" +" -- "+env.getProperty("DBENGINE"));
}
}
ClassC.java
@Component("classc")
public class ClassC implements Runnable {
@Autowired
Provider<InterB> classAPrototypeobj;
public void doFromAbove() {
InterB cls = (InterB) classAPrototypeobj.get();
InterB cls1 = (InterB) classAPrototypeobj.get();
cls.dododo();
cls1.dododo();
System.out.println(cls);
System.out.println(cls1);
}
@Override
public void run() {
this.doFromAbove();
}
}
ClassConfig.java
@Configuration
@ComponentScan
public class ClassConfig {
}
Main Method
public static void main(String[] args) {
ClassC obj;
try(AbstractApplicationContext appctx = new AnnotationConfigApplicationContext(ClassConfig.class)) {
obj = (ClassC) appctx.getBean("classc");
}
Thread objThread = new Thread(obj);
objThread.start();
}
Updated Main Method(still has the same issue)
public static void main(String[] args) {
try(AbstractApplicationContext appctx = new AnnotationConfigApplicationContext(ClassConfig.class)) {
ClassC obj = (ClassC) appctx.getBean("classc");
Thread objThread = new Thread(obj);
objThread.start();
}
}
When Executed, This Causes NoSuchBeanDefinitionException for the bean 'environment'
But when we define the following in our Config Class, the error vanishes without a trace. This is the Workaround(but Spring's supposed to inject Environment automagically we shouldn't do this). Not sure how many such beans are not injected/@Autowired
@Bean
public Environment environment(ApplicationContext context) {
return context.getEnvironment();
}
I Suspect this is a Spring Framework Bug... Is it not?
StackTrace:
Exception in thread "Thread-1" org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'classA': Unsatisfied dependency expressed through field 'abcd'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'classB': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'environment' available
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:588)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:366)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1264)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:325)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:208)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1138)
at org.springframework.beans.factory.support.DefaultListableBeanFactory$DependencyObjectProvider.getObject(DefaultListableBeanFactory.java:1630)
at org.springframework.beans.factory.support.DefaultListableBeanFactory$Jsr330DependencyProvider.get(DefaultListableBeanFactory.java:1699)
at tpt.verifypoc.ClassC.doFromAbove(ClassC.java:28)
at tpt.verifypoc.ClassC.run(ClassC.java:39)
at java.lang.Thread.run(Thread.java:745)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'classB': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'environment' available
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:372)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1264)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:553)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:208)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1138)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:585)
... 14 more
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'environment' available
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanDefinition(DefaultListableBeanFactory.java:687)
at org.springframework.beans.factory.support.AbstractBeanFactory.getMergedLocalBeanDefinition(AbstractBeanFactory.java:1207)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:284)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:202)
at org.springframework.beans.factory.config.DependencyDescriptor.resolveCandidate(DependencyDescriptor.java:208)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$ShortcutDependencyDescriptor.resolveShortcut(AutowiredAnnotationBeanPostProcessor.java:740)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1077)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1066)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.resolvedCachedArgument(AutowiredAnnotationBeanPostProcessor.java:548)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.access$200(AutowiredAnnotationBeanPostProcessor.java:117)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:577)
at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:366)
... 25 more
Note:
- Spring: 4.3.9.RELEASE
- JSR330: javax.inject Version 1
回答1:
I would say this isn't a bug in Spring looking at your code before you start to use the objects you are closing the ApplicationContext. Or actually the try-with-resources block you have does that.
public static void main(String[] args) {
ClassC obj;
try(AbstractApplicationContext appctx = new AnnotationConfigApplicationContext(ClassConfig.class)) {
obj = (ClassC) appctx.getBean("classc");
}
Thread objThread = new Thread(obj);
objThread.start();
}
Is basically the same as
public static void main(String[] args) {
ClassC obj;
AbstractApplicationContext appctx = new AnnotationConfigApplicationContext(ClassConfig.class)) {
obj = (ClassC) appctx.getBean("classc");
appctx.close();
Thread objThread = new Thread(obj);
objThread.start();
}
You are closing the ApplicationContext before you are using the objects. What remains is an instanceof ClassC with a half backed proxy of Provided<ClassB> which needs to context to lookup certain beans. However it has no-way of looking up those beans as you pulled the registry from underneath it.
When you are closing the ApplicationContext you are shutting down your application. I would expect that your objects that still live are now invalid, because the container the belong to is destroyed.
Compare the code to JDBC code. You are opening a Connection, close the connection and afterwards try to prepare a statement on a closed connection. JDBC won't allow this because the Connection is closed and thus invalid.
Compare it to Microsoft Excel, you open it, work in a Sheet, write a macro. Close excel and expect the macro still to run.
来源：https://stackoverflow.com/questions/45076679/threaded-beans-doesnt-get-environment-autowired-to-them-in-spring-when-using-j