程序老是莫名的死掉

Question

2009-9-7 0:20:59 org.apache.catalina.core.ApplicationDispatcher invoke
严重: Servlet.service() for servlet jsp threw exception
javax.servlet.jsp.JspException: Cannot find bean: "news" in scope: "request"
at org.apache.struts.taglib.TagUtils.lookup(TagUtils.java:866)
at org.apache.struts.taglib.logic.IterateTag.doStartTag(IterateTag.java:236)
at org.apache.jsp.press.list_005fsearch_jsp._jspService(list_005fsearch_jsp.java:152)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
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:654)
at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:445)
at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:379)
at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:292)
at org.apache.struts.chain.commands.servlet.PerformForward.handleAsForward(PerformForward.java:113)
at org.apache.struts.chain.commands.servlet.PerformForward.perform(PerformForward.java:96)
at org.apache.struts.chain.commands.AbstractPerformForward.execute(AbstractPerformForward.java:54)
at org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:190)
at org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:304)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:190)
at org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
at org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:449)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:690)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at com.hlt.util.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:24)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:233)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
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:263)
at org.apache.jk.server.JkCoyoteHandler.invoke(JkCoyoteHandler.java:190)
at org.apache.jk.common.HandlerRequest.invoke(HandlerRequest.java:283)
at org.apache.jk.common.ChannelSocket.invoke(ChannelSocket.java:767)
at org.apache.jk.common.ChannelSocket.processConnection(ChannelSocket.java:697)
at org.apache.jk.common.ChannelSocket$SocketConnection.runIt(ChannelSocket.java:889)
at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:690)
at java.lang.Thread.run(Thread.java:619)不知道这是什么原因,没人触发事件,自动报的错!

Answer 1

检查一下你的 news 的配置，他是有生命周期的哦，rquest的话，一次请求后，就是失效了。

Answer 2

Cannot find bean: "news" in scope: "request" 
就是在request范围内找不到news，所以存放news这个变量时，一定要注意使用的范围。放于session的话会好点。如果放到cookie中的话，那更好，不容易出错

Answer 3

严重: Servlet.service() for servlet jsp threw exception 
javax.servlet.jsp.JspException: Cannot find bean: "news" in scope: "request" 赞同

Answer 4

我想可能是你后台做了判断 查询不到这个news就不会往request里放 导致页面出现错误 恰好你页面没做判断
也不排除scope的可能解决办法你先用logic:notEmpty判断下news是否为空 然后再进行相应的操作

Answer 5

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Answer 6

 抛出的异常已经很清楚了，说是在request范围内没有news，说明你没有保存进去，然后就去取