Sto creando un progetto in java con delle pagine jsp. Come server virtuale uso Apache Tomcat. Ho questo errore se provo a collegarmi alla mia pagina sapete aiutarmi?
codice:
type Exception report  message  description The server encountered an internal error () that prevented it from fulfilling this request.  exception  org.apache.jasper.JasperException: java.lang.NullPointerException 	org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:522) 	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:416) 	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342) 	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267) 	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)  root cause  java.lang.NullPointerException 	it.unisalento.db_interface.dao.PersonaDAO.isValidate(PersonaDAO.java:30) 	it.unisalento.core.Core.login(Core.java:22) 	org.apache.jsp.Redirect_jsp._jspService(Redirect_jsp.java:66) 	org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70) 	javax.servlet.http.HttpServlet.service(HttpServlet.java:717) 	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:374) 	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:342) 	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:267) 	javax.servlet.http.HttpServlet.service(HttpServlet.java:717)  note The full stack trace of the root cause is available in the Apache Tomcat/6.0.20 logs.