Spring使用@Autowired不能注入BlockingQueue的问题

今天遇到一个问题，使用spring4配置BlockingQueue，在Java代码里面使用@Autowired注释方式注入该BlockingQueue，一直报错。

我的代码如下：

    @Autowired
    private BlockingQueue<CoreTask> alarmInnerQueue;

我的XML如下：

<bean id="alarmInnerQueue" class="org.kanpiaoxue.test.concurrent.UniqueLinkedBlockingQueue"/>

说明一下，UniqueLinkedBlockingQueue 这个类是BlockingQueue的一个实现，我自己写的。

报错如下：

Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private java.util.concurrent.BlockingQueue com.baidu.rigel.dmap.sf.service.impl.AlarmFailureServiceImplTest.alarmInnerQueue; nested exception is org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type 'java.util.HashMap$Values' to required type 'java.util.concurrent.BlockingQueue'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.util.HashMap$Values] to required type [java.util.concurrent.BlockingQueue]: no matching editors or conversion strategy found
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:555)
	at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:87)
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331)
	... 26 more
Caused by: org.springframework.beans.ConversionNotSupportedException: Failed to convert value of type 'java.util.HashMap$Values' to required type 'java.util.concurrent.BlockingQueue'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.util.HashMap$Values] to required type [java.util.concurrent.BlockingQueue]: no matching editors or conversion strategy found
	at org.springframework.beans.TypeConverterSupport.doConvert(TypeConverterSupport.java:74)
	at org.springframework.beans.TypeConverterSupport.convertIfNecessary(TypeConverterSupport.java:40)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1014)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:949)
	at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:527)
	... 28 more
Caused by: java.lang.IllegalStateException: Cannot convert value of type [java.util.HashMap$Values] to required type [java.util.concurrent.BlockingQueue]: no matching editors or conversion strategy found
	at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:287)
	at org.springframework.beans.TypeConverterDelegate.convertIfNecessary(TypeConverterDelegate.java:107)
	at org.springframework.beans.TypeConverterSupport.doConvert(TypeConverterSupport.java:64)
	... 32 more

最后在spring的网站发现这是一个Bug，到现在还没有修复。而是采用了配置

javax.annotation.Resource的方式来绕过这个BUG。

正确的代码如下：

    @Resource(name="alarmInnerQueue")
    private BlockingQueue<CoreTask> alarmInnerQueue;

网站地址：https://jira.spring.io/browse/SPR-7798

http://forum.spring.io/forum/spring-projects/container/64548-problem-injecting-blockingqueue-by-applicationcontext-xml

内容：

Details

Type: Bug
Status: RESOLVED
Priority: Minor
Resolution: Duplicate
Affects Version/s: 3.0.5
Fix Version/s: None
Component/s: Core:AOP
Labels:
None

Reference URL:
http://forum.springsource.org/showthread.php?t=72474
Last commented by a User:
true

Description

Cannot @Autowire to inject an instance of java.util.concurrent.BlockingQueue. The above forum has a post from 2009. I was able to reproduce this problem and have attached a minimal example. This works with XML based bean configuration but not with the annotation @Autowired.

AppComponent.java:

 
             package com.example; 
            
             import java.util.concurrent.BlockingQueue; 
            
             import org.springframework.beans.factory.annotation.Autowired; 
            
             import org.springframework.context.support.ClassPathXmlApplicationContext; 
            
             import org.springframework.stereotype.Component; 
            
             @Component 
            
             public class AppComponent { 
            
             @Autowired 
            
             public BlockingQueue queue; 
            
             public static void main(String[] args) { 
            
             new ClassPathXmlApplicationContext("com/example/context.xml").getBean(AppComponent.class); 
            
             } 
            
             }

Config.java:

 
             package com.example; 
            
             import java.util.concurrent.BlockingQueue; 
            
             import java.util.concurrent.LinkedBlockingQueue; 
            
             import org.springframework.context.annotation.Bean; 
            
             import org.springframework.context.annotation.Configuration; 
            
             @Configuration 
            
             public class Config { 
            
             @Bean 
            
             public BlockingQueue blockingQueue() { 
            
             return new LinkedBlockingQueue(); 
            
             } 
            
             }

context.xml:

 
             <? 
             xml 
             version 
             = 
             "1.0" 
             encoding 
             = 
             "UTF-8" 
             ?> 
            
             < 
             beans 
             xmlns 
             = 
             "http://www.springframework.org/schema/beans" 
            
             xmlns:context 
             = 
             "http://www.springframework.org/schema/context" 
            
             xmlns:xsi 
             = 
             "http://www.w3.org/2001/XMLSchema-instance" 
            
             xsi:schemaLocation=" 
            
             http://www.springframework.org/schema/beans  
            
             http://www.springframework.org/schema/beans/spring-beans-3.0.xsd 
            
             http://www.springframework.org/schema/context 
            
             http://www.springframework.org/schema/context/spring-context-2.5.xsd 
            
             "> 
            
             < 
             context:component-scan 
             base-package 
             = 
             "com.example" 
             /> 
            
             </ 
             beans 
             >

The runtime error is:

 
             Exception in thread "main" org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'appComponent': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: public java.util.concurrent.BlockingQueue com.example.AppComponent.queue; nested exception is org.springframework.beans.FatalBeanException: No element type declared for collection [java.util.concurrent.BlockingQueue] 
            
             at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:285) 
            
             at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1074) 
            
             at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:517) 
            
             at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456) 
            
             at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:291) 
            
             at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222) 
            
             at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:288) 
            
             at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:190) 
            
             at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:580) 
            
             at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:895) 
            
             at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:425) 
            
             at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:139) 
            
             at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:83) 
            
             at com.example.AppComponent.main(AppComponent.java:17) 
            
             Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: public java.util.concurrent.BlockingQueue com.example.AppComponent.queue; nested exception is org.springframework.beans.FatalBeanException: No element type declared for collection [java.util.concurrent.BlockingQueue] 
            
             at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:502) 
            
             at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:84) 
            
             at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:282) 
            
             ... 13 more 
            
             Caused by: org.springframework.beans.FatalBeanException: No element type declared for collection [java.util.concurrent.BlockingQueue] 
            
             at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:740) 
            
             at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:703) 
            
             at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:474) 
            
             ... 15 more

Attachments

inject-blocking.zip

07/Dec/10 10:35 AM

3.54 MB

Issue Links

is superseded by

SPR-8519 Support injection of collection-typed beans using @Autowired+@Qualifier or @Inject+@Named

RESOLVED

Activity

Michael F added a comment - 05/Jul/11 7:13 AM

(I posted the same response in the forum thread linked above.)

If you want auto-wire the Queue try to use JSR-250's @Resource annotation and a reasonable qualifier. Spring supports these annotations and should correctly inject the queue.)

 
                @Component 
               
                public class B { 
               
                @Resource(name="myBlockingQueue") 
               
                private BlockingQueue<Integer> blockingQueue; 
               
                }

@Autowired and @Resource behave differently.

Background info can be found in the documentation: Fine-tuning annotation-based autowiring with qualifiers

Chris Beams added a comment - 07/Jul/11 6:51 PM

Please see ~~SPR-8519~~, which aims to address this and a number of other similar issues related to collection autowiring.

Marty Kube added a comment - 10/Jul/11 6:16 PM

Great, thanks. @Resource solved the issue.