debug in tomcat

[alex]

hi all!! i got a problem with my code. and the most of all. i cannot find where i made mistake. i was stuck for several days. who can help me? Location: /usertable/userlist.jsp Internal Servlet Error: org.apache.jasper.JasperException: Unable to compile class for JSP at org.apache.jasper.servlet.JspServlet.doLoadJSP(JspServlet.java:476) at org.apache.jasper.servlet.JasperLoader12.loadJSP(JasperLoader12.java:146) at org.apache.jasper.servlet.JspServlet.loadJSP(JspServlet.java:433) at org.apache.jasper.servlet.JspServlet$JspServletWrapper.loadIfNecessary(JspSe rvlet.java:152) at org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(JspServlet.ja va:164) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:318) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:391) at javax.servlet.http.HttpServlet.service(HttpServlet.java:853) at org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:404) at org.apache.tomcat.core.Handler.service(Handler.java:286) at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372) at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:79 7) at org.apache.tomcat.core.ContextManager.service(ContextManager.java:743) at org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpC onnectionHandler.java:210) at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:416) at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:498) at java.lang.Thread.run(Thread.java:484) Root cause: java.lang.NullPointerException at org.apache.jasper.compiler.TagBeginGenerator.generateSetters(TagBeginGenerat or.java:196) at org.apache.jasper.compiler.TagBeginGenerator.generateServiceMethodStatements (TagBeginGenerator.java:291) at org.apache.jasper.compiler.TagBeginGenerator.generate(TagBeginGenerator.java :360) at org.apache.jasper.compiler.JspParseEventListener$GeneratorWrapper.generate(J spParseEventListener.java:773) at org.apache.jasper.compiler.JspParseEventListener.generateAll(JspParseEventLi stener.java:220) at org.apache.jasper.compiler.JspParseEventListener.endPageProcessing(JspParseE ventListener.java:175) at org.apache.jasper.compiler.Compiler.compile(Compiler.java:183) at org.apache.jasper.servlet.JspServlet.doLoadJSP(JspServlet.java:462) at org.apache.jasper.servlet.JasperLoader12.loadJSP(JasperLoader12.java:146) at org.apache.jasper.servlet.JspServlet.loadJSP(JspServlet.java:433) at org.apache.jasper.servlet.JspServlet$JspServletWrapper.loadIfNecessary(JspSe rvlet.java:152) at org.apache.jasper.servlet.JspServlet$JspServletWrapper.service(JspServlet.ja va:164) at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:318) at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:391) at javax.servlet.http.HttpServlet.service(HttpServlet.java:853) at org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java:404) at org.apache.tomcat.core.Handler.service(Handler.java:286) at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java:372) at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java:79 7) at org.apache.tomcat.core.ContextManager.service(ContextManager.java:743) at org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpC onnectionHandler.java:210) at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java:416) at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java:498) at java.lang.Thread.run(Thread.java