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我想盡可能優雅地處理我的web應用程序中的錯誤。
當然，我已經RTFM並添加以下到我的web.xml文件：ZK錯誤處理：在初始請求期間與AJAX請求
<!-- WEB-INF/web.xml -->
<error-page>
<exception-type>java.lang.Throwable</exception-type>
<location>/error.zul</location>
</error-page>
這是基本的Java webapp error handling偉大工程。作爲ZK是一個AJAXy框架，頁面已經呈現後，可能會被拋出一個錯誤，因此ZK提供它自己的錯誤處理，這也：
<!-- zk.xml -->
<error-page>
<exception-type>java.lang.Throwable</exception-type>
<location>/zk/common/error.zul</location>
</error-page>
這個偉大的工程也，但是，他們沒有發揮好。當AU請求期間時引發的錯誤，ZK錯誤消息顯示，因爲它應該但我得到以下到stderr：再次
Feb 26, 2013 10:37:04 PM org.zkoss.zk.ui.http.DHtmlLayoutServlet handleError:273
WARNING: Failed to load the error page: /zk/common/error.zul
java.lang.IllegalStateException: getOutputStream() has already been called for this response
at org.apache.catalina.connector.Response.getWriter(Response.java:611)
at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:198)
at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:112)
at org.zkoss.zk.ui.http.DHtmlLayoutServlet.process(DHtmlLayoutServlet.java:168)
at org.zkoss.zk.ui.http.DHtmlLayoutServlet.handleError(DHtmlLayoutServlet.java:267)
at org.zkoss.zk.ui.http.DHtmlLayoutServlet.doGet(DHtmlLayoutServlet.java:138)
at org.zkoss.zk.ui.http.DHtmlLayoutServlet.doPost(DHtmlLayoutServlet.java:149)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:551)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:488)
at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:416)
at org.apache.catalina.core.StandardHostValve.throwable(StandardHostValve.java:270)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:680)
Feb 26, 2013 10:37:04 PM org.apache.catalina.core.ApplicationDispatcher invoke
SEVERE: Servlet.service() for servlet auEngine threw exception
java.lang.IllegalStateException: getOutputStream() has already been called for this response
at org.apache.catalina.connector.Response.getWriter(Response.java:611)
at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:198)
at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:112)
at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:112)
at org.zkoss.web.servlet.dsp.ServletDspContext.getOut(ServletDspContext.java:113)
at org.zkoss.web.servlet.dsp.impl.TextNode.interpret(TextNode.java:44)
at org.zkoss.web.servlet.dsp.impl.RootNode.interpret(RootNode.java:51)
at org.zkoss.web.servlet.dsp.impl.RootNode.interpret(RootNode.java:60)
at org.zkoss.web.util.resource.DspExtendlet.service(DspExtendlet.java:92)
at org.zkoss.web.util.resource.ClassWebResource.web0(ClassWebResource.java:583)
at org.zkoss.web.util.resource.ClassWebResource.web(ClassWebResource.java:569)
at org.zkoss.web.util.resource.ClassWebResource.service(ClassWebResource.java:260)
at org.zkoss.zk.au.http.DHtmlUpdateServlet.doGet(DHtmlUpdateServlet.java:392)
at org.zkoss.zk.au.http.DHtmlUpdateServlet.doPost(DHtmlUpdateServlet.java:464)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:551)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:488)
at org.zkoss.web.servlet.Servlets.include(Servlets.java:882)
at org.zkoss.zk.ui.http.Utils.handleError(Utils.java:143)
at org.zkoss.zk.ui.http.DHtmlLayoutServlet.handleError(DHtmlLayoutServlet.java:278)
at org.zkoss.zk.ui.http.DHtmlLayoutServlet.doGet(DHtmlLayoutServlet.java:138)
at org.zkoss.zk.ui.http.DHtmlLayoutServlet.doPost(DHtmlLayoutServlet.java:149)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:551)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:488)
at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:416)
at org.apache.catalina.core.StandardHostValve.throwable(StandardHostValve.java:270)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:680)
Feb 26, 2013 10:37:04 PM org.apache.catalina.core.ApplicationDispatcher invoke
SEVERE: Servlet.service() for servlet zkLoader threw exception
java.lang.IllegalStateException: getOutputStream() has already been called for this response
at org.apache.catalina.connector.Response.getWriter(Response.java:611)
at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:198)
at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:112)
at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:112)
at org.zkoss.web.servlet.dsp.ServletDspContext.getOut(ServletDspContext.java:113)
at org.zkoss.web.servlet.dsp.impl.TextNode.interpret(TextNode.java:44)
at org.zkoss.web.servlet.dsp.impl.RootNode.interpret(RootNode.java:51)
at org.zkoss.web.servlet.dsp.impl.RootNode.interpret(RootNode.java:60)
at org.zkoss.web.util.resource.DspExtendlet.service(DspExtendlet.java:92)
at org.zkoss.web.util.resource.ClassWebResource.web0(ClassWebResource.java:583)
at org.zkoss.web.util.resource.ClassWebResource.web(ClassWebResource.java:569)
at org.zkoss.web.util.resource.ClassWebResource.service(ClassWebResource.java:260)
at org.zkoss.zk.au.http.DHtmlUpdateServlet.doGet(DHtmlUpdateServlet.java:392)
at org.zkoss.zk.au.http.DHtmlUpdateServlet.doPost(DHtmlUpdateServlet.java:464)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:551)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:488)
at org.zkoss.web.servlet.Servlets.include(Servlets.java:882)
at org.zkoss.zk.ui.http.Utils.handleError(Utils.java:143)
at org.zkoss.zk.ui.http.DHtmlLayoutServlet.handleError(DHtmlLayoutServlet.java:278)
at org.zkoss.zk.ui.http.DHtmlLayoutServlet.doGet(DHtmlLayoutServlet.java:138)
at org.zkoss.zk.ui.http.DHtmlLayoutServlet.doPost(DHtmlLayoutServlet.java:149)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:551)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:488)
at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:416)
at org.apache.catalina.core.StandardHostValve.throwable(StandardHostValve.java:270)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:680)
Feb 26, 2013 10:37:04 PM org.apache.catalina.core.StandardHostValve custom
SEVERE: Exception Processing ErrorPage[exceptionType=java.lang.Throwable, location=/error.zul]
java.lang.IllegalStateException: getOutputStream() has already been called for this response
at org.apache.catalina.connector.Response.getWriter(Response.java:611)
at org.apache.catalina.connector.ResponseFacade.getWriter(ResponseFacade.java:198)
at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:112)
at javax.servlet.ServletResponseWrapper.getWriter(ServletResponseWrapper.java:112)
at org.zkoss.web.servlet.dsp.ServletDspContext.getOut(ServletDspContext.java:113)
at org.zkoss.web.servlet.dsp.impl.TextNode.interpret(TextNode.java:44)
at org.zkoss.web.servlet.dsp.impl.RootNode.interpret(RootNode.java:51)
at org.zkoss.web.servlet.dsp.impl.RootNode.interpret(RootNode.java:60)
at org.zkoss.web.util.resource.DspExtendlet.service(DspExtendlet.java:92)
at org.zkoss.web.util.resource.ClassWebResource.web0(ClassWebResource.java:583)
at org.zkoss.web.util.resource.ClassWebResource.web(ClassWebResource.java:569)
at org.zkoss.web.util.resource.ClassWebResource.service(ClassWebResource.java:260)
at org.zkoss.zk.au.http.DHtmlUpdateServlet.doGet(DHtmlUpdateServlet.java:392)
at org.zkoss.zk.au.http.DHtmlUpdateServlet.doPost(DHtmlUpdateServlet.java:464)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:551)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:488)
at org.zkoss.web.servlet.Servlets.include(Servlets.java:882)
at org.zkoss.zk.ui.http.Utils.handleError(Utils.java:143)
at org.zkoss.zk.ui.http.DHtmlLayoutServlet.handleError(DHtmlLayoutServlet.java:278)
at org.zkoss.zk.ui.http.DHtmlLayoutServlet.doGet(DHtmlLayoutServlet.java:138)
at org.zkoss.zk.ui.http.DHtmlLayoutServlet.doPost(DHtmlLayoutServlet.java:149)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:646)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:551)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:488)
at org.apache.catalina.core.StandardHostValve.custom(StandardHostValve.java:416)
at org.apache.catalina.core.StandardHostValve.throwable(StandardHostValve.java:270)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:141)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:293)
at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:859)
at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:602)
at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:489)
at java.lang.Thread.run(Thread.java:680)
，這是當ZK特定錯誤處理程序（在/zk/common/error.zul）截獲該錯誤。根據堆棧跟蹤，似乎錯誤傳播到普通的Java webapp錯誤處理程序（在/error.zul處）。
如果第一次呈現頁面時發生錯誤，則會按預期方式顯示普通錯誤處理程序（位於/error.zul）而不是頁面，並且不記錄任何問題。
有關如何解決此問題的任何想法？ 可以/我應該在我的ZK錯誤處理程序上做些什麼來阻止錯誤傳播？