S2SH ,hibernate的问题吗？ 大量数据导出到exclle时报错?报错

怎么解决这个错误？o

The server encountered an internal error () that prevented it from fulfilling this request.

exception

java.lang.reflect.InvocationTargetException
	sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
	sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
	java.lang.reflect.Method.invoke(Method.java:597)
	com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:450)
	com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:289)
	com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:252)
	org.apache.struts2.interceptor.MessageStoreInterceptor.intercept(MessageStoreInterceptor.java:194)
	com.opensymphony.xwork2.Defaul

org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54)
	org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:563)
	org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
	org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99)

root cause

java.lang.OutOfMemoryError: Java heap space

note The full stack trace of the root cause is available in the Apache Tomcat/6.0.29 logs.