I got the following error
HTTP Status 500 -
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:548)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:471)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:389)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:333)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
ahp.CompareCriterionSlider.doGet(CompareCriterionSlider.java:35)
javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
root cause
java.lang.NullPointerException
org.apache.jsp.CompareCriterionSlider_jsp._jspService(CompareCriterionSlider_jsp.java:91)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:433)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:389)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:333)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
ahp.CompareCriterionSlider.doGet(CompareCriterionSlider.java:35)
javax.servlet.http.HttpServlet.service(HttpServlet.java:621)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
For the line: dispatcher.forward(request, response);
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
HttpSession session = request.getSession(true);
session.setAttribute("criterions", CriterionRecommander.values() );
RequestDispatcher dispatcher = getServletContext().getRequestDispatcher("/CompareCriterionSlider.jsp");
dispatcher.forward(request, response);
}
I have CompareCriterionSlider.jsp
in the dir WebContent/
I tried to set break point to debug it, but eclipse(Version: Indigo Service Release 2) gives me: Source not found.
Whoever down voted me care to give a reason?
There is a null pointer exception thrown from your JSP and you need to find the exact line of code in your JSP that is causing it.
One way to do it is to simply open the compiled java file of the jsp ie CompareCriterionSlider_jsp.java:91 and then map it to the line in the JSP.
Once you do that , given it is a null pointer it should be straightforward figuring the error.
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