JSP custom error page - Exception variable is null

Question

I am creating a simple custom error page for my JSP application that is running on tomcat 7. I am having an issue printing the exception. The exception variable when printed:

<%= exception %>

is always null.

web.xml

<error-page>
  <error-code>404</error-code>
   <location>/error.jsp</location>
</error-page>
<error-page>
  <error-code>500</error-code>
  <location>/error.jsp</location>
</error-page>

<error-page>
  <exception-type>java.lang.Exception</exception-type>
  <location>/error.jsp</location>
</error-page>

error.jsp

<%@ page isErrorPage="true" import="java.io.*" %>
<!DOCTYPE html>

<html lang="en">
  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <meta name="description" content="">
    <meta name="author" content="">

  <title>Error Page</title>
  </head>
  <body>
     <div>
       <h3>Error</h3> 
       <h4><b>Exception:</b><br></h4> 
       <p><i><%= exception %></i><p>
     </div>

     <footer></footer>
  </body>

Directive

I also added:

<%@ page errorPage="errorPage.jsp" %>

to all of my pages.

Error

When this runs it just will print null for the exception variable. If I try and change it to
exception.printStackTrace(response.getWriter()

I will get an error that looks like this:

SEVERE: Exception Processing ErrorPage[errorCode=404, location=/error.jsp]
org.apache.jasper.JasperException: /error.jsp (line: 1, column: 32) equal symbol expected

Look at http://stackoverflow.com/questions/8135980/how-can-i-print-error-stack-trace-in-jsp-page — rickz, Mar 05 '14 at 01:26

Luiggi Mendoza · Accepted Answer · 2014-03-04T22:27:27.540

Use Expression Language instead:

<%@ page isErrorPage="true" %>
<!DOCTYPE html>

<html lang="en">
  <head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <meta name="description" content="">
    <meta name="author" content="">
  <title>Error Page</title>
  </head>
  <body>
     <div>
       <h3>Error</h3> 
       <h4><b>Exception:</b><br></h4> 
       <p><i>${pageContext.exception.message}</i><p>
     </div>
     <footer></footer>
  </body>
</html>

Note that this will print the exception only if it comes from an Exception when generating the JSP e.g. having a scriptlet code that throws an unhandled Exception. If it comes from a 400 or 500 HTTP response code, it won't print any text at all.

JSP custom error page - Exception variable is null

web.xml

error.jsp

Directive

Error

1 Answers1