修复BeanNotOfRequiredTypeException对非单例bean的Spring代理转换? [英] Fixing BeanNotOfRequiredTypeException on Spring proxy cast on a non-singleton bean?
问题描述
我在从应用程序上下文中提取Spring bean时遇到问题。
I'm having an issue with pulling a Spring bean from an application context.
当我尝试时;
InnerThread instance = (InnerThread) SpringContextFactory.getApplicationContext().getBean("innerThread", InnerThread.class);
我得到;
org.springframework.beans.factory.BeanNotOfRequiredTypeException: Bean named 'innerThread' must be of type [com.generic.InnerThread], but was actually of type [$Proxy26]
如果没有在getBean()调用中指定的类,我会得到一个ClassCastException(你可以在下面看到)。
Without the specified class in the getBean() call I get a ClassCastException (which you can see in detail below).
InnerThread bean正在初始化为非单例,因为我需要多个实例。 InnerThread类也扩展了Thread。有趣的是,此错误显示在OuterThread中,其设置方式与InnerThread完全相同。
The InnerThread bean is being initialized as a non-singleton, because I need multiple instances. The InnerThread class also extends Thread. The interesting thing is that this error shows up within OuterThread, which is set up in the exact same way the InnerThread is.
我试图在下面包括所有相关的代码列表/堆栈跟踪。是否有更多Spring体验的人能告诉我这里发生了什么?
I've tried to include all relevant code listings/stack traces below. Could someone with more Spring experience tell me what is going on here?
OuterThread.java代码段
public class OuterThread extends Thread {
private Queue<InnerThread> createInnerThreads() {
Queue<InnerThread> threads = new ArrayBlockingQueue();
ApplicationContext ctx = SpringContextFactory.getApplicationContext();
int i = 0;
for (SearchRule search : searches) {
logger.debug("Number of times looped " + i++);
//Seprated lines to get a better sense of what is going on
Object proxy = ctx.getBean("innerThread", InnerThread.class);
logger.debug(ReflectionToStringBuilder.toString(proxy));
logger.debug("proxy.getClass(): " + proxy.getClass());
logger.debug("proxy.getClass().getClassLoader(): " + proxy.getClass().getClassLoader());
logger.debug("proxy.getClass().getDeclaringClass(): " + proxy.getClass().getDeclaringClass());
logger.debug("InnerThread.class.getClassLoader(): " + InnerThread.class.getClassLoader());
//---Exception here---
InnerThread cst = (InnerThread) proxy;
threads.add(cst);
}
return threads;
}
public static void main(String[] args) throws Exception {
try {
OuterThread instance = (OuterThread) SpringContextFactory.getApplicationContext().getBean("outerThread", OuterThread.class);
instance.run();
} catch (Exception ex) {
logger.error("Fatal exception.", ex);
throw ex;
}
}
}
SpringContextFactory.java :
SpringContextFactory.java:
public class SpringContextFactory {
static final Logger logger = LoggerFactory.getLogger(SpringContextFactory.class);
private static ApplicationContext ctx;
private static final String DEFAULT_PATH = "META-INF/app-context.xml";
public static ApplicationContext getApplicationContext() {
return getApplicationContext(DEFAULT_PATH);
}
public static synchronized ApplicationContext getApplicationContext(String path) {
if (ctx == null) return createApplicationContext(path);
else return ctx;
}
private static ApplicationContext createApplicationContext(String path) {
if (logger.isDebugEnabled()) logger.debug("Loading Spring Context...");
ctx = new ClassPathXmlApplicationContext(path);
if (logger.isDebugEnabled()) logger.debug("Spring Context Loaded");
return ctx;
}
}
$ b
app-context.xml:
<?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-2.5.xsd">
<!-- persistence context from separate jar -->
<import resource="persistence-context.xml"/>
<bean id="outerThread" class="com.generic.OuterThread" scope="prototype"/>
<bean id="innerThread" class="com.generic.InnerThread" scope="prototype"/>
</beans>
堆栈跟踪
Stack Trace
2009-05-08 14:34:37,341 [main] DEBUG com.generic.OuterThread.init(OuterThread.java:59) - Initializing OuterThread object, com.generic.OuterThread@1c8fb4b[em=org.hibernate.ejb.EntityManagerImpl@e2892b,currentTime=java.util.GregorianCalendar[time=1241634874841,areFieldsSet=true,areAllFieldsSet=true,lenient=true,zone=sun.util.calendar.ZoneInfo[id="America/New_York",offset=-18000000,dstSavings=3600000,useDaylight=true,transitions=235,lastRule=java.util.SimpleTimeZone[id=America/New_York,offset=-18000000,dstSavings=3600000,useDaylight=true,startYear=0,startMode=3,startMonth=2,startDay=8,startDayOfWeek=1,startTime=7200000,startTimeMode=0,endMode=3,endMonth=10,endDay=1,endDayOfWeek=1,endTime=7200000,endTimeMode=0]],firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2009,MONTH=4,WEEK_OF_YEAR=19,WEEK_OF_MONTH=2,DAY_OF_MONTH=6,DAY_OF_YEAR=126,DAY_OF_WEEK=4,DAY_OF_WEEK_IN_MONTH=1,AM_PM=1,HOUR=2,HOUR_OF_DAY=14,MINUTE=34,SECOND=34,MILLISECOND=841,ZONE_OFFSET=-18000000,DST_OFFSET=3600000],maxConcurrentThreads=5,reconId=3,reportUsername=TEST,useOffset=false,username=removed,uuid=bf61494d-ff96-431c-a41f-1e292d0c9fbe,name={T,h,r,e,a,d,-,1},priority=5,threadQ=<null>,eetop=0,single_step=false,daemon=false,stillborn=false,target=<null>,group=java.lang.ThreadGroup[name=main,maxpri=10],contextClassLoader=sun.misc.Launcher$AppClassLoader@11b86e7,inheritedAccessControlContext=java.security.AccessControlContext@1524d43,threadLocals=<null>,inheritableThreadLocals=java.lang.ThreadLocal$ThreadLocalMap@2cbc86,stackSize=0,nativeParkEventPointer=0,tid=9,threadStatus=0,parkBlocker=<null>,blocker=<null>,blockerLock=java.lang.Object@a68fd8,stopBeforeStart=false,throwableFromStop=<null>,uncaughtExceptionHandler=<null>]
2009-05-08 14:34:37,341 [main] DEBUG org.springframework.orm.jpa.ExtendedEntityManagerCreator$ExtendedEntityManagerInvocationHandler.doJoinTransaction(ExtendedEntityManagerCreator.java:385) - No local transaction to join
2009-05-08 14:34:37,529 [main] DEBUG com.generic.OuterThread.createInnerThreads(OuterThread.java:139) - Number of times looped 0
2009-05-08 14:34:37,529 [main] DEBUG org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFactory.java:458) - Creating instance of bean 'searchThread' with merged definition [Root bean: class [com.generic.InnerThread]; scope=prototype; abstract=false; lazyInit=false; autowireCandidate=true; autowireMode=0; dependencyCheck=0; factoryBeanName=null; factoryMethodName=null; initMethodName=null; destroyMethodName=null; defined in class path resource [META-INF/app-context.xml]]
2009-05-08 14:34:37,545 [main] DEBUG com.generic.InnerThread.<init>(InnerThread.java:50) - Constructing InnerThread object, com.generic.InnerThread@1080876[em=<null>,coolScheme=<null>,coolUrl=<null>,date=<null>,error=<null>,millisecondsTaken=0,thresholdMet=false,reconId=0,result=-2,searchId=0,username=<null>,uuid=<null>,name={T,h,r,e,a,d,-,2},priority=5,threadQ=<null>,eetop=0,single_step=false,daemon=false,stillborn=false,target=<null>,group=java.lang.ThreadGroup[name=main,maxpri=10],contextClassLoader=sun.misc.Launcher$AppClassLoader@11b86e7,inheritedAccessControlContext=java.security.AccessControlContext@1524d43,threadLocals=<null>,inheritableThreadLocals=java.lang.ThreadLocal$ThreadLocalMap@3aef16,stackSize=0,nativeParkEventPointer=0,tid=10,threadStatus=0,parkBlocker=<null>,blocker=<null>,blockerLock=java.lang.Object@126c6ea,stopBeforeStart=false,throwableFromStop=<null>,uncaughtExceptionHandler=<null>]
2009-05-08 14:34:37,545 [main] DEBUG org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:203) - Returning cached instance of singleton bean 'entityManagerFactory'
2009-05-08 14:34:37,545 [main] DEBUG org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:203) - Returning cached instance of singleton bean 'org.springframework.transaction.config.internalTransactionAdvisor'
2009-05-08 14:34:37,560 [main] DEBUG org.springframework.transaction.interceptor.AbstractFallbackTransactionAttributeSource.getTransactionAttribute(AbstractFallbackTransactionAttributeSource.java:108) - Adding transactional method [report] with attribute [PROPAGATION_REQUIRED,ISOLATION_DEFAULT]
2009-05-08 14:34:37,560 [main] DEBUG org.springframework.aop.framework.autoproxy.AbstractAutoProxyCreator.buildAdvisors(AbstractAutoProxyCreator.java:494) - Creating implicit proxy for bean 'searchThread' with 0 common interceptors and 1 specific interceptors
2009-05-08 14:34:37,560 [main] DEBUG org.springframework.aop.framework.JdkDynamicAopProxy.getProxy(JdkDynamicAopProxy.java:113) - Creating JDK dynamic proxy: target source is SingletonTargetSource for target object [com.generic.InnerThread@1080876]
2009-05-08 14:34:37,591 [main] DEBUG com.generic.OuterThread.createInnerThreads(OuterThread.java:141) - $Proxy26@1594a88[h=org.springframework.aop.framework.JdkDynamicAopProxy@1f0cf51]
2009-05-08 14:34:37,591 [main] DEBUG com.generic.OuterThread.createInnerThreads(OuterThread.java:142) - proxy.getClass(): class $Proxy26
2009-05-08 14:34:37,591 [main] DEBUG com.generic.OuterThread.createInnerThreads(OuterThread.java:143) - proxy.getClass().getClassLoader(): sun.misc.Launcher$AppClassLoader@11b86e7
2009-05-08 14:34:37,591 [main] DEBUG com.generic.OuterThread.createInnerThreads(OuterThread.java:144) - proxy.getClass().getDeclaringClass(): null
2009-05-08 14:34:37,591 [main] DEBUG com.generic.OuterThread.createInnerThreads(OuterThread.java:145) - InnerThread.class.getClassLoader(): sun.misc.Launcher$AppClassLoader@11b86e7
2009-05-08 14:34:37,591 [main] ERROR com.generic.OuterThread.run(OuterThread.java:101) - Exception in OuterThread, ending reconciliation.
java.lang.ClassCastException: $Proxy26 cannot be cast to com.generic.InnerThread
at com.generic.OuterThread.createInnerThreads(OuterThread.java:148)
at com.generic.OuterThread.run(OuterThread.java:65)
at com.generic.OuterThread.main(OuterThread.java:170)
类似问题没有回答我的问题
- 自动投放Spring Bean
- ClassCastException。
- Auto-cast Spring Beans
- ClassCastException when casting to the same class.
- 使用
的BeanNotOfRequiredTypeException ServiceLocatorFactoryBean和
@Transactional
(搜索后经过几个小时的搜索,发现这已经回答了百万次。
- 第6.6节Spring
文档。 - Java:implements Runnablevs.extends Thread
- BeanNotOfRequiredTypeException using ServiceLocatorFactoryBean and @Transactional (Nothing better then finding a thread off Google after hours of searching to have a response that says "This has already been answered a million times.")
- Section 6.6 in the Spring Docs.
- Java: "implements Runnable" vs. "extends Thread"
Similar questions that do not answer my question
推荐答案
再次,在花了几个小时试图调试这之后,我在StackOverflow上发布后找到了答案。
Once again, after spending hours trying to debug this I find the answer right after posting on StackOverflow.
我从我的问题中留下的一个关键点是InnerThread有一个事务方法(对不起,认为这是不相关的)。这是OuterThread和InnerThread之间的重要区别。
A key point that I left out from my question is that InnerThread has a transactional method (sorry thought this was irrelevant). This is the important difference between OuterThread and InnerThread.
从 Spring文档:
注意
Note
在运行时,多个节将折叠成一个统一的自动代理创建器,它应用指定的任何节(通常来自不同的XML bean定义文件)的最强代理设置。
Multiple sections are collapsed into a single unified auto-proxy creator at runtime, which applies the strongest proxy settings that any of the sections (typically from different XML bean definition files) specified. This also applies to the and elements.
要清楚:使用proxy-target-class =true'将强制使用
To be clear: using 'proxy-target-class="true"' on , or elements will force the use of CGLIB proxies for all three of them.
将以上内容添加到我的配置中(基于persistance-context.xml) ,你可以看到加载上面)线似乎解决了这个问题。但是,我认为这可能是一个快速解决方法,而不是真正的解决方案。
Adding the above to my configuration (based in persistance-context.xml, which you can see loaded above) line seems to fix the problem. However, I think this may be a quick fix workaround as opposed to real solution.
我想我有一些更深层次的问题,春天作为混乱而被删除。第二,我应该使用 Spring的任务执行器启动我的主题。第三个我的线程应该实现Runnable而不是扩展Thread(见下面的问题)。
I think I've got a few deeper issues here, number one being that I find Spring as confusing as expletive deleted. Second I should probably be using Spring's TaskExecutor to kick off my threads. Third my threads should implement Runnable instead of extending Thread (See SO question below).
另请参见
这篇关于修复BeanNotOfRequiredTypeException对非单例bean的Spring代理转换?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!