Java Tutorial/JSP/Error Page
Содержание
Display Error Message In Error Handling Page
index.jsp
<%@ page errorPage="errorPage.jsp" %>
<HTML>
<HEAD>
<TITLE>Using the exception Object</TITLE>
</HEAD>
<BODY>
<H1>Using the exception Object</H1>
<%
int value = 1;
value = value / 0;
%>
</BODY>
</HTML>
Error page
<%--
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("<table border="1" cellpadding="3">");
sb.append("<tr>");
sb.append("<th colspan="2">");
sb.append(title);
sb.append("</th>");
sb.append("</tr>");
// 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("<tr>");
sb.append("<td>");
sb.append(key);
sb.append("</td>");
sb.append("<td>");
sb.append(value);
sb.append("</td>");
sb.append("</tr>");
}
// Generate the footer lines
sb.append("</table>");
// Return the generated HTML
return sb.toString();
}
%>
Pass Message to Error Handling Page
index.jsp
<%@ page errorPage="errorPage.jsp" %>
<HTML>
<HEAD>
<TITLE>Using request Object Attributes</TITLE>
</HEAD>
<BODY>
<H1>Using request Object Attributes</H1>
<%
request.setAttribute("message", "Divide by zero.");
int value = 1;
value = value / 0;
%>
</BODY>
</HTML>
Provide Error Handling Page
index.jsp
<%@ page errorPage="errorPage.jsp" %>
<HTML>
<HEAD>
<TITLE>Using an Error Page</TITLE>
</HEAD>
<BODY>
<H1>Using an Error Page</H1>
<%
int value = 1;
value = value / 0;
%>
</BODY>
</HTML>
