java.lang.IllegalArgumentException: Method must not be null

Nested in 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: Method must not be null:java.lang.IllegalArgumentException: Method must not be null  

i am getting this deployment error while deploying my application.

java -version
java version "1.6.0_20"
Java(TM) SE Runtime Environment (build 1.6.0_20-b02)
Java HotSpot(TM) Server VM (build 16.3-b01, mixed mode)  

while the same build gets deployed successfully in the same server jetty 6.1.3 with following conf.

java version "1.6.0_17"

spring version used is 2.5.6.SEC01

how to overcome, googling didnt work?

    2010-05-13 15:53:20.903::WARN:  Failed startup of context org.mortbay.jetty.webapp.WebAppContext@9ad840{/caw,jar:file:/home/jigar/jetty-6.1.3/webapps/caw.war!/}
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: Method must not be null
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:480)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFactory.java:409)
    at java.security.AccessController.doPrivileged(Native Method)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:380)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:264)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    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(AbstractApplicationContext.java:515)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:362)
    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.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler.java:530)
    at org.mortbay.jetty.servlet.Context.startContext(Context.java:135)
    at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1218)
    at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:500)
    at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:448)
    at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40)
    at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:147)
    at org.mortbay.jetty.handler.ContextHandlerCollection.doStart(ContextHandlerCollection.java:161)
    at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40)
    at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:147)
    at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40)
    at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:117)
    at org.mortbay.jetty.Server.doStart(Server.java:210)
    at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40)
    at org.mortbay.xml.XmlConfiguration.main(XmlConfiguration.java:929)
    at sun.reflect.Native开发者_开发百科MethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.mortbay.start.Main.invokeMain(Main.java:183)
    at org.mortbay.start.Main.start(Main.java:497)
    at org.mortbay.start.Main.main(Main.java:115)
Caused by: java.lang.IllegalArgumentException: Method must not be null
    at org.springframework.util.Assert.notNull(Assert.java:112)
    at org.springframework.core.BridgeMethodResolver.findBridgedMethod(BridgeMethodResolver.java:63)
    at org.springframework.beans.GenericTypeAwarePropertyDescriptor.<init>(GenericTypeAwarePropertyDescriptor.java:58)
    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.getPropertyDescriptorInternal(BeanWrapperImpl.java:282)
    at org.springframework.beans.BeanWrapperImpl.isWritableProperty(BeanWrapperImpl.java:333)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1247)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1010)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:472)
    ... 35 more
2010-05-13 15:53:20.906::WARN:  Nested in 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: Method must not be null:
java.lang.IllegalArgumentException: Method must not be null
    at org.springframework.util.Assert.notNull(Assert.java:112)
    at org.springframework.core.BridgeMethodResolver.findBridgedMethod(BridgeMethodResolver.java:63)
    at org.springframework.beans.GenericTypeAwarePropertyDescriptor.<init>(GenericTypeAwarePropertyDescriptor.java:58)
    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.getPropertyDescriptorInternal(BeanWrapperImpl.java:282)
    at org.springframework.beans.BeanWrapperImpl.isWritableProperty(BeanWrapperImpl.java:333)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues(AbstractAutowireCapableBeanFactory.java:1247)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1010)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:472)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory$1.run(AbstractAutowireCapableBeanFactory.java:409)
    at java.security.AccessController.doPrivileged(Native Method)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:380)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:264)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:222)
    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(AbstractApplicationContext.java:515)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:362)
    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.mortbay.jetty.handler.ContextHandler.startContext(ContextHandler.java:530)
    at org.mortbay.jetty.servlet.Context.startContext(Context.java:135)
    at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1218)
    at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:500)
    at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:448)
    at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40)
    at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:147)
    at org.mortbay.jetty.handler.ContextHandlerCollection.doStart(ContextHandlerCollection.java:161)
    at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40)
    at org.mortbay.jetty.handler.HandlerCollection.doStart(HandlerCollection.java:147)
    at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40)
    at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:117)
    at org.mortbay.jetty.Server.doStart(Server.java:210)
    at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:40)
    at org.mortbay.xml.XmlConfiguration.main(XmlConfiguration.java:929)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.mortbay.start.Main.invokeMain(Main.java:183)
    at org.mortbay.start.Main.start(Main.java:497)
    at org.mortbay.start.Main.main(Main.java:115)
2010-05-13 15:53:20.964::INFO:  Started SelectChannelConnector @ 0.0.0.0:8090

This can be caused by a dirty classpath with different versions of Spring libraries all over the place. Cleanup it and align it to the one and same Spring version with the correct versioned dependencies.