java.lang.NullPointerException

at org.apache.struts2.components.UIBean.evaluateParams(UIBean.java:827)

at org.apache.struts2.components.UIBean.end(UIBean.java:535)

at org.apache.struts2.views.jsp.ComponentTagSupport.doEndTag(ComponentTagSupport.java:42)

at org.apache.jsp.AddProduct_jsp._jspx_meth_s_005ftextfield_005f0(AddProduct_jsp.java:174)

at org.apache.jsp.AddProduct_jsp._jspx_meth_s_005fform_005f0(AddProduct_jsp.java:132)

at org.apache.jsp.AddProduct_jsp._jspService(AddProduct_jsp.java:79)

at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)

at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)

at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:395)

at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:339)

at javax.servlet.http.HttpServlet.service(HttpServlet.java:731)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)

at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)

at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:96)

at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)

at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)

at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220)

at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122)

at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505)

at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170)

at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)

at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950)

at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)

at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423)

at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079)

at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:620)

at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)

at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)

at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)

at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)

at java.lang.Thread.run(Thread.java:745)