org.apache.jasper.JasperException: Unable to compile class for JSP

web.xml檔案中，加入一下代碼出現的錯誤：<servlet>
    <servlet-name>debugjsp</servlet-name>
    <description>Added to compile JSPs with debug info</description>
    <servlet-class>org.apache.jasper.servlet.JspServlet</servlet-class>
    <init-param>
      <param-name>classdebuginfo</param-name>
      <param-value>true</param-value>
    </init-param>
    <load-on-startup>3</load-on-startup>
  </servlet>
<servlet-mapping>
    <servlet-name>debugjsp</servlet-name>
    <url-pattern>*.jsp</url-pattern>
  </servlet-mapping>

 錯誤資訊如下：org.apache.jasper.JasperException: Unable to compile class for JSP
    at org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:97)
    at org.apache.jasper.compiler.ErrorDispatcher.javacError(ErrorDispatcher.java:346)
    at org.apache.jasper.compiler.Compiler.generateClass(Compiler.java:414)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:472)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:451)
    at org.apache.jasper.compiler.Compiler.compile(Compiler.java:439)
    at org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:511)
    at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:295)
    at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
    at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
    at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:704)
    at org.apache.catalina.core.ApplicationDispatcher.processRequest(ApplicationDispatcher.java:474)
    at org.apache.catalina.core.ApplicationDispatcher.doForward(ApplicationDispatcher.java:409)
    at org.apache.catalina.core.ApplicationDispatcher.forward(ApplicationDispatcher.java:312)
    at waf.controller.web.action.HTMLAction.forwardAction(HTMLAction.java:154)
    at components.admin.logon.actions.LogOnAction.run(LogOnAction.java:54)
    at waf.controller.web.RequestProcessor.processRequest(RequestProcessor.java:98)
    at waf.controller.web.MainServlet.doProcess(MainServlet.java:95)
    at waf.controller.web.MainServlet.doPost(MainServlet.java:60)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:237)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:157)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:214)
    at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
    at org.apache.catalina.core.StandardContextValve.invokeInternal(StandardContextValve.java:198)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:152)
    at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:137)
    at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:118)
    at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:102)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
    at org.apache.catalina.core.StandardValveContext.invokeNext(StandardValveContext.java:104)
    at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:520)
    at org.apache.catalina.core.ContainerBase.invoke(ContainerBase.java:929)
    at org.apache.coyote.tomcat5.CoyoteAdapter.service(CoyoteAdapter.java:160)
    at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:799)
    at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:705)
    at org.apache.tomcat.util.net.TcpWorkerThread.runIt(PoolTcpEndpoint.java:577)
    at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:683)
    at java.lang.Thread.run(Unknown Source)

將web.xml中的添加的那些資訊刪除，問題解決。