淘宝网表现层设计分析.doc

淘宝网表现层设计分析 前几天突然发现淘宝网访问非常慢而且出错(出现异常)，猜测是淘宝网在发布新版本时出现错误或是某个服务器出现异常。但淘宝网的工程师在输出错误时生成了客户端注释掉的Java异常信息(包含在之间)，虽然在画面上是看不到的，但查看源代码就可以清楚的看到这个Java出错信息。 淘宝网采用阿里巴巴自己开发的一个MVC框架，动态网页(jhtml页面)的通用入是口WebxControllerServlet，最终调用/执行模版是在TemplateModule的子类中完成的，然后在Module执行完成后跳转到一个视图(JSP文件)，在Servlet和Module中是通过Valve的职责链处理。图1 淘宝网部分类图 一个Web请求的基本处理流程是： 客户端发出Web请求 WebxControllerServlet PerformScreenTemplateValve TemplateModule附(本文基于下面的异常分析)： Exception: com.alibaba.webx.WebxException: Failed to execute screen: home.MyTaobao (template: screen/home/myTaobao.vm) at com.alibaba.webx.WebxControllerServlet.handleRequest(WebxControllerServlet.java:111) at com.alibaba.webx.controller.AbstractWebxControllerServlet.doGet(AbstractWebxControllerServlet.java:113) at javax.servlet.http.HttpServlet.service(HttpServlet.java:690) at javax.servlet.http.HttpServlet.service(HttpServlet.java:803) at org.apache.catalina.core.ApplicationFilterCernalDoFilter(ApplicationFilterChain.java:290) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at com.alibaba.webx.filter.rundata.RunDataFilter.doFilter(RunDataFilter.java:48) at com.alibaba.webx.filter.AbstractFilter.doFilter(AbstractFilter.java:150) at org.apache.catalina.core.ApplicationFilterCernalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at mon.webx.filter.RemoteAddrFilter.doFilter(RemoteAddrFilter.java:16) at com.alibaba.webx.filter.AbstractFilter.doFilter(AbstractFilter.java:150) at org.apache.catalina.core.ApplicationFilterCernalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at com.alibaba.webx.filter.timer.TimerFilter.doFilter(TimerFilter.java:93) at com.alibaba.webx.filter.AbstractFilter.doFilter(AbstractFilter.java:150) at org.apache.catalina.core.ApplicationFilterCernalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96) at org.apache.catalina.core.ApplicationFilterCernalDoFilter(ApplicationFilterChain.java:235) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175) at org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:179) at org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:84) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102) at org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:157) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:262) at org.apache.coyote.ajp.AjpAprPcess(AjpAprProcessor.java:419) at org.apache.coyote.ajp.AjpAprProtocol$AjpConnectionHcess(AjpAprProtocol.java:378) at .AprEndpoint$Worker.run(AprEndpoint.java:1508) at java.lang.Thread.run(Thread.java:595) Caused by: com.alibaba.service.pipeline.PipelineException: Failed to execute screen: home.MyTaobao (template: screen/home/myTaobao.vm) at com.alibaba.turbine.pipeline.PerformScreenTemplateValve.performScreenModule (PerformScreenTemplateValve.java:112) at com.alibaba.turbine.pipeline.PerformScreenTemplateValve.invoke(PerformScreenTemplateValve.java:48) at com.alibaba.turbine.pipeline.AbstractValve.invoke(AbstractValve.java:33) at com.alibaba.service.pipeline.DefaultPipeline.invokeNext(DefaultPipeline.java:224) at com.alibaba.service.pipeline.DefaultPipeline.invoke(DefaultPipeline.java:187) at com.alibaba.turbine.pipeline.ChooseValve$Condition.invokeSubPipeline(ChooseValve.java:82) at com.alibaba.turbine.pipeline.ChooseValve.invoke(ChooseValve.java:57) at com.alibaba.turbine.pipeline.AbstractValve.invoke(AbstractValve.java:33) at com.alibaba.service.pipeline.DefaultPipeline.invokeNext(DefaultPipeline.java:224) at com.alibaba.service.pipeline.DefaultPipeline.invoke(DefaultPipeline.java:187) at com.alibaba.service.pipeline.TryCatchFinallyValve.invokeTryPipeline(TryCatchFinallyValve.java:114) at com.alibaba.webx.WebxControllerServlet.handleRequest(WebxControllerServlet.java:108) . 33 more Caused by: com.alibaba.webx.WebxException: MyTaobao Response is null or failed at com.taobao.web.mytaoba