STRUTS2:Committed before 500,java.lang.IllegalStateException: Committed

2012-12-01 09:51:29.689::WARN:  Committed before 500 Unable to show problem report: java.lang.IllegalStateException: STREAM
2012-12-01 09:51:29.690::WARN:  /strutsDemo/export: 
java.lang.IllegalStateException: Committed
	at org.mortbay.jetty.Response.resetBuffer(Response.java:853)
	at org.mortbay.jetty.Response.reset(Response.java:832)
	at org.mortbay.jetty.Response.sendError(Response.java:220)
	at org.apache.struts2.dispatcher.Dispatcher.sendError(Dispatcher.java:801)
	at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:519)
	at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
	at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)
	at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1041)
	at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:354)
	at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:226)
	at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:627)
	at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:149)
	at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:123)
	at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:141)
	at org.mortbay.jetty.Server.handle(Server.java:269)
	at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:430)
	at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:687)
	at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:492)
	at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:199)
	at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:339)
	at org.mortbay.jetty.nio.HttpChannelEndPoint.run(HttpChannelEndPoint.java:270)
	at org.mortbay.thread.BoundedThreadPool$PoolThread.run(BoundedThreadPool.java:475)
2012-12-01 09:51:29.691::WARN:  /strutsDemo/export
java.lang.IllegalStateException: Committed
	at org.mortbay.jetty.Response.resetBuffer(Response.java:853)
	at org.mortbay.jetty.Response.reset(Response.java:832)
	at org.mortbay.jetty.Response.sendError(Response.java:220)
	at org.apache.struts2.dispatcher.Dispatcher.sendError(Dispatcher.java:801)
	at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:519)
	at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77)
	at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:91)
	at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1041)
	at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:354)
	at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:226)
	at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:627)
	at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:149)
	at org.mortbay.jetty.handler.HandlerCollection.handle(HandlerCollection.java:123)
	at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:141)
	at org.mortbay.jetty.Server.handle(Server.java:269)
	at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:430)
	at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:687)
	at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:492)
	at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:199)
	at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:339)
	at org.mortbay.jetty.nio.HttpChannelEndPoint.run(HttpChannelEndPoint.java:270)
	at org.mortbay.thread.BoundedThreadPool$PoolThread.run(BoundedThreadPool.java:475)

服务端对于大数据量的文件产生流返回给客户端时间耗时比较长，结果客户端接受不到数据
[img]http://dl.iteye.com/upload/attachment/0077/2950/6ca0bf76-7c0c-37a3-b9e4-e1cd44e5f400.jpg[/img]