<%@ page contentType="text/html; charset=UTF-8" %> Prelude and Coda Example - Gumdrop JSP

Prelude and Coda Example

What you're seeing: This JSP page demonstrates automatic inclusion of content via JSP property group configuration. Notice the header section above (prelude) and footer section below (coda) that were automatically added by Gumdrop's JSP processing.

How Prelude and Coda Work

This page is configured in web.xml with JSP property groups that specify:

Include Prelude: Content automatically inserted at the beginning
Include Coda: Content automatically inserted at the end

Web.xml Configuration

<jsp-property-group>
    <url-pattern>/jsp/enhanced/*</url-pattern>
    <include-prelude>/WEB-INF/includes/header-prelude.jsp</include-prelude>
    <include-coda>/WEB-INF/includes/footer-coda.jsp</include-coda>
</jsp-property-group>

Main Page Content

This is the actual content of the JSP file. The header and footer you see are automatically included by Gumdrop's JSP implementation based on the configuration in web.xml.

The prelude (header-prelude.jsp) includes:

Common variable declarations available to this page
Initialization code that runs before the main page
HTML header content with server information

The coda (footer-coda.jsp) includes:

Performance metrics calculation
Request information display
HTML footer content

Accessing Prelude Variables

Variables and methods declared in the prelude are available in this page:

Server Info: <%= request.getAttribute("serverInfo") %>
Current Time: <%= new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new java.util.Date()) %>
Session Active: <%= session != null ? "Yes" : "No" %>

Processing Order

When Gumdrop processes this JSP, the following happens:

JSP property groups are resolved based on the URL pattern
Include preludes are identified and processed first
The main JSP content is processed
Include codas are processed last
All content is combined into a single servlet
The servlet is compiled and executed

Benefits

Consistent Layout: Automatic headers/footers across page groups
Common Functionality: Shared variables and methods
Performance Monitoring: Automatic timing and metrics
Maintenance: Single point of change for common elements
Security: Consistent authentication/authorization checks

Implementation Note: Gumdrop's JSPPropertyGroupResolver handles multiple property groups with cumulative prelude/coda lists, applying them in the order they appear in web.xml.

Sample JSP Source

The actual source of this JSP file contains only the main content. The prelude and coda are automatically added during processing:

<%@ page contentType="text/html; charset=UTF-8" %>
<!DOCTYPE html>
<html>
<head>
    <title>Prelude and Coda Example - Gumdrop JSP</title>
    
</head>
<body>
    
    <h1>Prelude and Coda Example</h1>
    
</body>
</html>