UnsupportedClassVersionError & eclipse下@override报错

碰到了这么个问题：

[14:30:26.244] javax.servlet.ServletException: Unable to instantiate Action, com.ambow.upgrade.extraction.action.DataExtractAction,  defined for 'syncAction' in namespace '/datasync'Error creating bean with name 'classStuRealExtractService' defined in file [/opt/resin/webapps/lylearnnet/WEB-INF/classes/spring/applicationContext-dataExtract.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.ambow.upgrade.extraction.service.impl.ClassStuRealExtractServiceImpl]: Constructor threw exception; nested exception is java.lang.UnsupportedClassVersionError: com/ambow/upgrade/extraction/dao/ClassStuRealExtractDAO : unsupported classversion 50.0
[14:30:26.244]  at com.opensymphony.webwork.dispatcher.DispatcherUtils.serviceAction(DispatcherUtils.java:236)
[14:30:26.244]  at com.opensymphony.webwork.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:202)
[14:30:26.244]  at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:73)
[14:30:26.244]  at com.ambow.core.web.filter.FilterLogin.doFilter(FilterLogin.java:62)
[14:30:26.244]  at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:73)
[14:30:26.244]  at com.ambow.core.web.filter.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:238)
[14:30:26.244]  at com.ambow.sso.client.filter.SsoFilter.doFilter(SsoFilter.java:97)
[14:30:26.244]  at com.ambow.core.web.filter.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:250)
[14:30:26.244]  at com.ambow.core.web.filter.FilterChainProxy.doFilter(FilterChainProxy.java:129)
[14:30:26.244]  at com.ambow.core.web.filter.FilterToBeanProxy.doFilter(FilterToBeanProxy.java:73)
[14:30:26.244]  at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:73)
[14:30:26.244]  at org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:198)
[14:30:26.244]  at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:75)
[14:30:26.244]  at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:73)
[14:30:26.244]  at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:96)
[14:30:26.244]  at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:75)
[14:30:26.244]  at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:73)
[14:30:26.244]  at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:175)
[14:30:26.244]  at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:240)
[14:30:26.244]  at com.caucho.server.hmux.HmuxRequest.handleRequest(HmuxRequest.java:424)
[14:30:26.244]  at com.caucho.server.port.TcpConnection.run(TcpConnection.java:481)
[14:30:26.244]  at com.caucho.util.ThreadPool$Item.runTasks(ThreadPool.java:685)
[14:30:26.244]  at com.caucho.util.ThreadPool$Item.run(ThreadPool.java:607)
[14:30:26.244]  at java.lang.Thread.run(Thread.java:595)
[14:30:26.244] Caused by: Unable to instantiate Action, com.ambow.upgrade.extraction.action.DataExtractAction,  defined for 'syncAction' in namespace '/datasync'Error creating bean with name 'classStuRealExtractService' defined in file [/opt/resin/webapps/lylearnnet/WEB-INF/classes/spring/applicationContext-dataExtract.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.ambow.upgrade.extraction.service.impl.ClassStuRealExtractServiceImpl]: Constructor threw exception; nested exception is java.lang.UnsupportedClassVersionError: com/ambow/upgrade/extraction/dao/ClassStuRealExtractDAO : unsupported classversion 50.0
[14:30:26.244]  at com.opensymphony.xwork.DefaultActionInvocation.createAction(DefaultActionInvocation.java:243)
[14:30:26.244]  at com.opensymphony.xwork.DefaultActionInvocation.init(DefaultActionInvocation.java:322)
[14:30:26.244]  at com.opensymphony.xwork.DefaultActionInvocation.<init>(DefaultActionInvocation.java:71)
[14:30:26.244]  at com.opensymphony.xwork.DefaultActionInvocation.<init>(DefaultActionInvocation.java:64)
[14:30:26.244]  at com.opensymphony.xwork.DefaultActionProxyFactory.createActionInvocation(DefaultActionProxyFactory.java:28)
[14:30:26.244]  at com.opensymphony.xwork.DefaultActionProxy.prepare(DefaultActionProxy.java:148)
[14:30:26.244]  at com.opensymphony.xwork.DefaultActionProxy.<init>(DefaultActionProxy.java:78)
[14:30:26.244]  at com.opensymphony.xwork.DefaultActionProxyFactory.createActionProxy(DefaultActionProxyFactory.java:46)
[14:30:26.244]  at com.opensymphony.webwork.dispatcher.DispatcherUtils.serviceAction(DispatcherUtils.java:216)
[14:30:26.244]  ... 23 more
[14:30:26.244] Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'classStuRealExtractService' defined in file [/opt/resin/webapps/lylearnnet/WEB-INF/classes/spring/applicationContext-dataExtract.xml]: Instantiation of bean failed; nested exception is org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.ambow.upgrade.extraction.service.impl.ClassStuRealExtractServiceImpl]: Constructor threw exception; nested exception is java.lang.UnsupportedClassVersionError: com/ambow/upgrade/extraction/dao/ClassStuRealExtractDAO : unsupported classversion 50.0
[14:30:26.244]  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:451)
[14:30:26.244]  at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:270)
[14:30:26.244]  at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:160)
[14:30:26.244]  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireByName(AbstractAutowireCapableBeanFactory.java:881)
[14:30:26.244]  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:829)
[14:30:26.244]  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireBeanProperties(AbstractAutowireCapableBeanFactory.java:276)
[14:30:26.244]  at com.opensymphony.xwork.spring.SpringObjectFactory.autoWireBean(SpringObjectFactory.java:153)
[14:30:26.244]  at com.opensymphony.xwork.spring.SpringObjectFactory.buildBean(SpringObjectFactory.java:140)
[14:30:26.244]  at com.opensymphony.xwork.spring.SpringObjectFactory.buildBean(SpringObjectFactory.java:117)
[14:30:26.244]  at com.opensymphony.xwork.ObjectFactory.buildAction(ObjectFactory.java:101)
[14:30:26.244]  at com.opensymphony.xwork.DefaultActionInvocation.createAction(DefaultActionInvocation.java:224)
[14:30:26.244]  ... 31 more
[14:30:26.244] Caused by: org.springframework.beans.BeanInstantiationException: Could not instantiate bean class [com.ambow.upgrade.extraction.service.impl.ClassStuRealExtractServiceImpl]: Constructor threw exception; nested exception is java.lang.UnsupportedClassVersionError: com/ambow/upgrade/extraction/dao/ClassStuRealExtractDAO : unsupported classversion 50.0
[14:30:26.244]  at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:100)
[14:30:26.244]  at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:61)
[14:30:26.244]  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:759)
[14:30:26.244]  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:724)
[14:30:26.244]  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:387)
[14:30:26.244]  ... 41 more
[14:30:26.244] Caused by: java.lang.UnsupportedClassVersionError: com/ambow/upgrade/extraction/dao/ClassStuRealExtractDAO : unsupported classversion 50.0
[14:30:26.244]  at java.lang.ClassLoader.defineClass1(Native Method)
[14:30:26.244]  at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
[14:30:26.244]  at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124)
[14:30:26.244]  at com.caucho.loader.DynamicClassLoader.loadClass(DynamicClassLoader.java:1329)
[14:30:26.244]  at com.caucho.loader.DynamicClassLoader.findClass(DynamicClassLoader.java:1199)
[14:30:26.244]  at com.caucho.loader.DynamicClassLoader.loadClass(DynamicClassLoader.java:1119)
[14:30:26.244]  at com.caucho.loader.DynamicClassLoader.loadClass(DynamicClassLoader.java:1068)
[14:30:26.244]  at com.ambow.upgrade.extraction.service.impl.ClassStuRealExtractServiceImpl.<init>(ClassStuRealExtractServiceImpl.java:32)
[14:30:26.244]  at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
[14:30:26.244]  at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
[14:30:26.244]  at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
[14:30:26.244]  at java.lang.reflect.Constructor.newInstance(Constructor.java:494)
[14:30:26.244]  at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:85)
[14:30:26.244]  at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:61)
[14:30:26.244]  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateBean(AbstractAutowireCapableBeanFactory.java:759)
[14:30:26.244]  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:724)
[14:30:26.244]  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:387)
[14:30:26.244]  at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:270)
[14:30:26.244]  at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:160)
[14:30:26.244]  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireByName(AbstractAutowireCapableBeanFactory.java:881)
[14:30:26.244]  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:829)
[14:30:26.244]  at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.autowireBeanProperties(AbstractAutowireCapableBeanFactory.java:277)
[14:30:26.244]  at com.opensymphony.xwork.spring.SpringObjectFactory.autoWireBean(SpringObjectFactory.java:153)
[14:30:26.244]  at com.opensymphony.xwork.spring.SpringObjectFactory.buildBean(SpringObjectFactory.java:140)
[14:30:26.244]  at com.opensymphony.xwork.spring.SpringObjectFactory.buildBean(SpringObjectFactory.java:117)
[14:30:26.244]  at com.opensymphony.xwork.ObjectFactory.buildAction(ObjectFactory.java:101)
[14:30:26.244]  at com.opensymphony.xwork.DefaultActionInvocation.createAction(DefaultActionInvocation.java:224)
[14:30:26.244]  at com.opensymphony.xwork.DefaultActionInvocation.init(DefaultActionInvocation.java:324)
[14:30:26.244]  at com.opensymphony.xwork.DefaultActionInvocation.<init>(DefaultActionInvocation.java:72)
[14:30:26.244]  at com.opensymphony.xwork.DefaultActionInvocation.<init>(DefaultActionInvocation.java:65)
[14:30:26.244]  at com.opensymphony.xwork.DefaultActionProxyFactory.createActionInvocation(DefaultActionProxyFactory.java:28)
[14:30:26.244]  at com.opensymphony.xwork.DefaultActionProxy.prepare(DefaultActionProxy.java:148)
[14:30:26.244]  at com.opensymphony.xwork.DefaultActionProxy.<init>(DefaultActionProxy.java:79)
[14:30:26.244]  at com.opensymphony.xwork.DefaultActionProxyFactory.createActionProxy(DefaultActionProxyFactory.java:46)
[14:30:26.244]  at com.opensymphony.webwork.dispatcher.DispatcherUtils.serviceAction(DispatcherUtils.java:216)
[14:30:26.244]  at com.opensymphony.webwork.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:202)
[14:30:26.244]  at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:74)
[14:30:26.244]  at com.ambow.core.web.filter.FilterLogin.doFilter(FilterLogin.java:62)
[14:30:26.244]  at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:74)
[14:30:26.244]  at com.ambow.core.web.filter.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:238)
[14:30:26.244]  at com.ambow.sso.client.filter.SsoFilter.doFilter(SsoFilter.java:99)
[14:30:26.244]  at com.ambow.core.web.filter.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:250)
[14:30:26.244]  at com.ambow.core.web.filter.FilterChainProxy.doFilter(FilterChainProxy.java:130)
[14:30:26.244]  at com.ambow.core.web.filter.FilterToBeanProxy.doFilter(FilterToBeanProxy.java:74)
[14:30:26.244]  at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:74)
[14:30:26.244]  at org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:198)
[14:30:26.244]  at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:75)
[14:30:26.244]  at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:74)
[14:30:26.244]  at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:97)
[14:30:26.244]  at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:75)
[14:30:26.244]  at com.caucho.server.dispatch.FilterFilterChain.doFilter(FilterFilterChain.java:74)
[14:30:26.244]  at com.caucho.server.webapp.WebAppFilterChain.doFilter(WebAppFilterChain.java:175)
[14:30:26.244]  at com.caucho.server.dispatch.ServletInvocation.service(ServletInvocation.java:241)
[14:30:26.244]  ... 5 more

应用部署在resin中；上传我本地的某个class文件后，访问action时抛出如上异常；java -version，发现linux下的jdk版本是1.5，而我本地是1.6的。更换编译器为1.5，重新上传编译后的class文件，即可。


参见：
Eclipse @override报错解决
http://justdo2008.iteye.com/blog/433579