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Editorial Team
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Asked: 2026-05-16T13:54:22+00:00

I’m having a tough time consolidating errors in my application. Currently, my error.jsp looks

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I’m having a tough time consolidating errors in my application. Currently, my error.jsp looks like following (part of it):

 <%@ page isErrorPage="true" %>
 <%@page contentType="text/html"%>
 <%@page import="java.util.*"%>
 <%@page import="javax.servlet.*"%>
 <%@page import="javax.servlet.http.*"%>
 <%@page import="java.util.Calendar"%>
 <%@page import="java.text.SimpleDateFormat"%>

<html>
<%
String code = null, message = null, type = null, uri = null, time = null;
Object codeObj=null, messageObj=null, typeObj=null;
if (request.getAttribute("javax.servlet.error.status_code") != null)
    codeObj = request.getAttribute("javax.servlet.error.status_code");
if (request.getAttribute("javax.servlet.error.message") != null)
    messageObj = request.getAttribute("javax.servlet.error.message");
if (request.getAttribute("javax.servlet.error.exception_type")!=null)
    typeObj = request.getAttribute("javax.servlet.error.exception_type");

if (codeObj != null) code = codeObj.toString();
if (messageObj != null) message = messageObj.toString();
if (typeObj != null) type = typeObj.toString();
uri = (String) request.getAttribute("javax.servlet.error.request_uri");
Calendar cal = Calendar.getInstance();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS");
time = sdf.format(cal.getTime());

String error = "Code:\t\t" + code + "\nType:\t\t" + type + "\nURL:\t\t" + uri + "\nTime:\t\t" + time +"\nMessage:\t" + message;
%>

This works fine in all scenarios except!:
Sometimes in my application I am catching built-in exceptions in MyException class with the following code:

catch(MyException ex){
    log.error(ex.getMessage(), uivex);
    String originalURL = "/errorpages/error.jsp?errorcode=" + (ex.getMajor() + ex.getMinor()) + "&errormessage=" + ex.getMessage();
    RequestDispatcher dispatcher = getServletContext().getRequestDispatcher(address);
    dispatcher.forward(request,response);   
}

Now the problem is that when I get forwarded to error.jsp page…Instead of seeing the actual error from MyException class..I’m seeing NullPointerException because nothing is present in javax.servlet.error.status_code and the page is declared as isErrorPage="true"

What should I do in this case? One solution is to make a completely different error.jsp (name it error1.jsp) page and forward the exceptions from MyException class to that page. Though, I would like to have everything in one place.

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1 Answer

  1. Editorial Team

    This code honestly hurts my eyes. Here is how a generic one should look like. You may find it useful.

    <%@ page pageEncoding="UTF-8" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/fmt" prefix="fmt" %>
<jsp:useBean id="date" class="java.util.Date" />
<!DOCTYPE html>
<html lang="en">
    <head>
        <title>Error</title>
        <link rel="stylesheet" href="style.css">
    </head>
    <body>
        <h1>Error</h1>
        <p>Unfortunately an unexpected error has occurred. Below you can find the error details.</p>
        <h2>Details</h2>
        <ul>
            <li>Timestamp: <fmt:formatDate value="${date}" type="both" dateStyle="long" timeStyle="long" />
            <li>Action: <c:out value="${requestScope['javax.servlet.forward.request_uri']}" />
            <li>Exception: <c:out value="${requestScope['javax.servlet.error.exception']}" />
            <li>Message: <c:out value="${requestScope['javax.servlet.error.message']}" />
            <li>Status code: <c:out value="${requestScope['javax.servlet.error.status_code']}" />
            <li>User agent: <c:out value="${header['user-agent']}" />
        </ul>
    </body>
</html>

    The @page isErrorPage is by the way only useful if you want to have the ${exception} (i.e. request.getAttribute("exception") available in the JSP. In this particular case you don’t need it.

    And indeed, do not forward in the catch block at all. Just let it go. It will be dealt by the error page then.

    } catch (MyException ex) {
    log.error(ex.getMessage(), uivex);
    throw ex; // Or throw new ServletException(ex.getMessage(), ex);
}
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