This seems to be caused by a slightly different implementation of the "java.beans.PropertyDescriptor" class in IBM's JDK class libraries... breaking an assumption in Spring's GenericTypeAwarePropertyDescriptor subclass. I've revised this for Spring 2.5.5, hopefully being compatible with IBM's JDK 1.6 as well now (again).

This will be available in tonight's 2.5.5 snapshot (build 489 or higher; available from http://static.springframework.org/downloads/nightly/snapshot-download.php?project=SPR). Please give it a try and let us know whether it works for you on IBM's JDK 1.6...

Juergen

you just add some assumption,but didn't resolve this problem actually.

2008-05-09 14:06:58,794 ERROR [org.springframework.web.context.ContextLoader] – Context initialization failed
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.beans.factory.config.PropertyPlaceholderConfigurer#0': Initialization of bean failed; nested exception is java.lang.IllegalArgumentException: Class must not be null
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBe
anFactory.java:478)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFacto
ry.java:409)
at java.security.AccessController.doPrivileged(AccessController.java:224)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBean
Factory.java:380)
at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:264)
at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.ja
va:220)
at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:261)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:185)
at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:164)
at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationC
ontext.java:516)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:363)
at org.springframework.web.context.ContextLoader.createWebApplicationContext(ContextLoader.java:255)
at org.springframework.web.context.ContextLoader.initWebApplicationContext(ContextLoader.java:199)
at org.springframework.web.context.ContextLoaderListener.contextInitialized(ContextLoaderListener.java:45)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:3843)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4350)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:791)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:771)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:525)
at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:829)
at org.apache.catalina.startup.HostConfig.deployWARs(HostConfig.java:718)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:490)
at org.apache.catalina.startup.HostConfig.check(HostConfig.java:1215)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:293)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
at org.apache.catalina.core.ContainerBase.backgroundProcess(ContainerBase.java:1337)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1601)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.processChildren(ContainerBase.java:1610)
at org.apache.catalina.core.ContainerBase$ContainerBackgroundProcessor.run(ContainerBase.java:1590)
at java.lang.Thread.run(Thread.java:735)
Caused by: java.lang.IllegalArgumentException: Class must not be null
at java.lang.Throwable.<init>(Throwable.java:67)
at org.springframework.util.Assert.notNull(Assert.java:112)
at org.springframework.core.GenericTypeResolver.resolveReturnType(GenericTypeResolver.java:98)
at org.springframework.beans.GenericTypeAwarePropertyDescriptor.getPropertyType(GenericTypeAwarePropertyDescriptor.jav
a:58)
at java.beans.PropertyDescriptor.setWriteMethod(Unknown Source)
at java.beans.PropertyDescriptor.<init>(Unknown Source)
at org.springframework.beans.GenericTypeAwarePropertyDescriptor.<init>(GenericTypeAwarePropertyDescriptor.java:47)
at org.springframework.beans.CachedIntrospectionResults.<init>(CachedIntrospectionResults.java:250)
at org.springframework.beans.CachedIntrospectionResults.forClass(CachedIntrospectionResults.java:144)
at org.springframework.beans.BeanWrapperImpl.getCachedIntrospectionResults(BeanWrapperImpl.java:252)
at org.springframework.beans.BeanWrapperImpl.convertForProperty(BeanWrapperImpl.java:380)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.convertForProperty(AbstractAutowireCap
ableBeanFactory.java:1287)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCa
pableBeanFactory.java:1248)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBe
anFactory.java:1008)
at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBe
anFactory.java:470)
... 29 more

I am sorry,I didn't update GenericTypeAwarePropertyDescriptor too, you can close this issue now,thanks.