[Springframework-developer] Re: Proxying target classes

[Rod J. <rod...@in...>]

I saw this once only and it was my fault (accidentally wrapped a String as
the target, rather than real object).

Are any of the methods, or the object itself, final?

Can you reproduce this in a failing test case so I can look at it? There
certainly should be a better error message, even if it's a CGLIB prob.

Regards,
Rod

----- Original Message -----
From: "Colin Sampaleanu" <col...@ex...>
To: <spr...@li...>;
<rod...@in...>
Sent: Wednesday, January 28, 2004 1:20 PM
Subject: Proxying target classes


> Rod,
>
> Have you ever seen cglib's EnhancerEmitter blow up on trying to create a
> proxy? I generally only have to proxy interfaces, so have not proxied
> classes too much so far, however I just had a case where I needed to
> proxy a class directly, and got the following exception:
>
>  method 'onMessage' due to throwable
> [org.springframework.beans.factory.BeanCrea
> tionException: Error creating bean with name 'packaging-engine' defined
> in class
> path resource [packaging-applicationContext.xml]: Initialization method
> of bean
> failed; nested exception is:
>         org.springframework.aop.framework.AopConfigException: Unexpected
> AOP exc
> eption; nested exception is:
>         java.lang.NullPointerException]
> 08:07:48,585 INFO  [JtaTransactionManager] Initiating transaction rollback
> 08:07:48,585 ERROR [LogInterceptor] RuntimeException:
> org.springframework.beans.factory.BeanCreationException: Error creating
> bean wit
> h name 'packaging-engine' defined in classpath resource
> [packaging-applicationCo
> ntext.xml]: Initialization method of bean failed; nested exception is:
>         org.springframework.aop.framework.AopConfigException: Unexpected
> AOP exc
> eption; nested exception is:
>         java.lang.NullPointerException
> org.springframework.aop.framework.AopConfigException: Unexpected AOP
> exception;
> nested exception is:
>         java.lang.NullPointerException
> java.lang.NullPointerException
>         at
> net.sf.cglib.proxy.EnhancerEmitter$4.getMethods(EnhancerEmitter.java:
> 407)
>         at
net.sf.cglib.proxy.NoOpGenerator.generate(NoOpGenerator.java:69)
>         at
> net.sf.cglib.proxy.EnhancerEmitter.emitMethods(EnhancerEmitter.java:4
> 31)
>         at
> net.sf.cglib.proxy.EnhancerEmitter.<init>(EnhancerEmitter.java:172)
>
> This is using BeanNameAutoProxyCreator, with proxyTargetClass set to
> true. I actually used another postprocessor just for this case, since
> normally I only care about interfaces, so there's nothing else in it:
>
>   <bean id="packaging-txAutoProxyCreator2"
>
class="org.springframework.aop.framework.autoproxy.BeanNameAutoProxyCreator"
>
>     <property name="proxyTargetClass"><value>true</value></property>
>     <property name="interceptorNames">
>       <list>
>         <idref bean="hibInterceptor"/>
>         <idref local="packaging-matchAllTxInterceptor"/>
>       </list>
>     </property>
>     <property name="beanNames">
>       <list>
>            <idref local="packaging-engine"/>
>       </list>
>     </property>
>   </bean>
>
> The class in question (Engine) is a fairly simple class. It implements
> no interfaces.
>
> Regards,
> Colin
>
>