Jakarta Struts Cookbook

14.7. Reusing a Common Page Layout with SiteMesh

Problem

You want render your application's pages using a common layout without having to change your JSP pages or your application's Struts configuration.

Solution

Use SiteMesh to wrap your application's pages with a common layout and other presentation features.

Discussion

SiteMesh (http://www.opensymphony.com/sitemesh/) is a web-page layout and decoration framework. It allows you to decorate the web pages of an existing application with a common layout. It provides similar features as Tiles but uses a completely different approach. When you use Tiles, you adopt the Tiles-way of doing things by constructing pages using Tiles custom JSP tags, creating definitions in a Tiles configuration file, and linking actions to Tiles using the TilesRequestProcessor. Tiles becomes a pervasive part of your web application.

SiteMesh takes a different approach. It uses a servlet filter to modify the HTTP responses generated by your application, with responses typically generated by JSP pages. SiteMesh amends the response based on settings in a configuration file.

Suppose you have a site with three web pages: a main page, and two secondary pages. The main page looks something like Figure 14-5.

Figure 14-5. Page slated for decoration by SiteMesh

The secondary pages referred to by the two hyperlinks are, like this page, simple. The struts-config.xml file for this ...