if you have Error while using diplay table ....

*exception*

javax.servlet.ServletException: org/apache/commons/lang/UnhandledException
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:272)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter
(MonitorFilter.java:368)
org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1085)
org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:398)
org.apache.struts.action.RequestProcessor.process
(RequestProcessor.java:241)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:432)
javax.servlet.http.HttpServlet.service(
HttpServlet.java:709)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.displaytag.filter.ResponseOverrideFilter.doFilter(ResponseOverrideFilter.java:125)
org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter
(MonitorFilter.java:368)

*root cause*
java.lang.NoClassDefFoundError: org/apache/commons/lang/UnhandledException
java.lang.Class.getDeclaredConstructors0(Native Method)
java.lang.Class.privateGetDeclaredConstructors(Class.java:2357)
java.lang.Class.getConstructor0(Class.java:2671)
java.lang.Class.newInstance0(Class.java:321) java.lang.Class.newInstance(
Class.java:303) java.beans.Introspector.instantiate(Introspector.java:1432)
java.beans.Introspector.findExplicitBeanInfo(Introspector.java:410)
java.beans.Introspector.(Introspector.java:359)
java.beans.Introspector.getBeanInfo(Introspector.java:159)
org.apache.jasper.compiler.Generator$TagHandlerInfo.(Generator.java:3713)
org.apache.jasper.compiler.Generator$GenerateVisitor.getTagHandlerInfo(
Generator.java:2120)
org.apache.jasper.compiler.Generator$GenerateVisitor.visit(Generator.java:1599)
org.apache.jasper.compiler.Node$CustomTag.accept(Node.java:1441)
org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2163)
org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2213)
org.apache.jasper.compiler.Generator$GenerateVisitor.visit(Generator.java:1705)
org.apache.jasper.compiler.Node$CustomTag.accept(Node.java:1441)
org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2163)
org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2213)
org.apache.jasper.compiler.Generator$GenerateVisitor.visit(Generator.java:1705)
org.apache.jasper.compiler.Node$CustomTag.accept(Node.java:1441)
org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2163)
org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2213)
org.apache.jasper.compiler.Node$Visitor.visit(Node.java:2219)
org.apache.jasper.compiler.Node$Root.accept(Node.java:456)
org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2163)
org.apache.jasper.compiler.Generator.generate(Generator.java:3305)
org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:198)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:295)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:276)
org.apache.jasper.compiler.Compiler.compile(Compiler.java:264)
org.apache.jasper.JspCompilationContext.compile(JspCompilationContext.java:563)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:303)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:314)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:264)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(
MonitorFilter.java:368) org.apache.struts.action.RequestProcessor.doForward(
RequestProcessor.java:1085)
org.apache.struts.action.RequestProcessor.processForwardConfig(
RequestProcessor.java:398) org.apache.struts.action.RequestProcessor.process
(RequestProcessor.java:241) org.apache.struts.action.ActionServlet.process(
ActionServlet.java:1196) org.apache.struts.action.ActionServlet.doPost(
ActionServlet.java:432) javax.servlet.http.HttpServlet.service(
HttpServlet.java:709) javax.servlet.http.HttpServlet.service(
HttpServlet.java:802) org.displaytag.filter.ResponseOverrideFilter.doFilter(
ResponseOverrideFilter.java:125)
org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(
MonitorFilter.java:368).

Include all apache common lang jar