Java Tutorial/JSP/Error Page

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Display Error Message In Error Handling Page

index.jsp



   <source lang="java">

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

   <HEAD>
       <TITLE>Using the exception Object</TITLE>
   </HEAD>
   <BODY>

Using the exception Object

       <%
           int value = 1;
           value = value / 0;
       %>
   </BODY>

</HTML></source>





Error page

   <source lang="java">

<%--

 Copyright (c) 2002 by Phil Hanna
 All rights reserved.
 
 You may study, use, modify, and distribute this
 software for any purpose provided that this
 copyright notice appears in all copies.
 
 This software is provided without warranty
 either expressed or implied.

--%> <%@ page

     errorPage="ErrorPage.jsp"
     import="java.io.*"
     import="java.util.*"

%> <%

  Enumeration enames;
  Map map;
  String title;
  // Print the request headers
  map = new TreeMap();
  enames = request.getHeaderNames();
  while (enames.hasMoreElements()) {
     String name = (String) enames.nextElement();
     String value = request.getHeader(name);
     map.put(name, value);
  }
  out.println(createTable(map, "Request Headers"));
  // Print the session attributes
  map = new TreeMap();
  enames = session.getAttributeNames();
  while (enames.hasMoreElements()) {
     String name = (String) enames.nextElement();
     String value = "" + session.getAttribute(name);
     map.put(name, value);
  }
  out.println(createTable(map, "Session Attributes"));

%> <%-- Define a method to create an HTML table --%> <%!

  private static String createTable(Map map, String title)
  {
     StringBuffer sb = new StringBuffer();
     // Generate the header lines
sb.append(""); sb.append(""); sb.append(""); sb.append(""); // Generate the table rows Iterator imap = map.entrySet().iterator(); while (imap.hasNext()) { Map.Entry entry = (Map.Entry) imap.next(); String key = (String) entry.getKey(); String value = (String) entry.getValue(); sb.append(""); sb.append(""); sb.append(""); sb.append(""); } // Generate the footer lines sb.append("
");
     sb.append(title);
sb.append("
");
        sb.append(key);
sb.append("
");
        sb.append(value);
sb.append("
");
     // Return the generated HTML
     return sb.toString();
  }

%></source>





Pass Message to Error Handling Page

index.jsp



   <source lang="java">

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

   <HEAD>
       <TITLE>Using request Object Attributes</TITLE>
   </HEAD>
   <BODY>

Using request Object Attributes

       <%
           request.setAttribute("message", "Divide by zero.");
           int value = 1;
           value = value / 0;
       %>
   </BODY>

</HTML></source>





Provide Error Handling Page

index.jsp



   <source lang="java">

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

   <HEAD>
       <TITLE>Using an Error Page</TITLE>
   </HEAD>
   <BODY>

Using an Error Page

       <%
           int value = 1;
           value = value / 0;
       %>
   </BODY>

</HTML></source>