Introduction to SSI

SSI (Server Side Includes) are directives that are placed in HTML pages, and evaluated on the server while the pages are being served. They let you add dynamically generated content to an existing HTML page, without having to serve the entire page via a CGI program, or other dynamic technology.

Within Tomcat SSI support can be added when using Tomcat as your HTTP server and you require SSI support. Typically this is done during development when you don’t want to run a web server like Apache.

Tomcat SSI support implements the same SSI directives as Apache. See the Apache Introduction to SSI for information on using SSI directives.

SSI support is available as a servlet and as a filter. You should use one or the other to provide SSI support but not both.

Servlet based SSI support is implemented using the class org.apache.catalina.ssi.SSIServlet. Traditionally, this servlet is mapped to the URL pattern “*.shtml”.

Filter based SSI support is implemented using the class org.apache.catalina.ssi.SSIFilter. Traditionally, this filter is mapped to the URL pattern “*.shtml”, though it can be mapped to “*” as it will selectively enable/disable SSI processing based on mime types. The contentType init param allows you to apply SSI processing to JSP pages, javascript, or any other content you wish.

By default SSI support is disabled in Tomcat.