[Springframework-developer] Re: Proxying target classes

[Colin S. <col...@ex...>]

The class is not final, and there are no final methods. And I was wrong, 
it actually already implemented one interface, InitializingBean.

I was definitely wrapping the right object, as afterwards I added a new 
service interface to the object, took out the proxyTargetClass property, 
and everything is now working fine. Unfortunately I need to get this 
code working and deployed today/tomorrow, so adding the interface was 
the easiest solution. In a day or two I can try to reproduce this in a 
test case...


Rod Johnson wrote:

>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
>>
>>
>>    
>>
>
>  
>