Question

How do you add an Expires or a Cache-Control header in JSP? I want to add a far-future expiration date in an include page for my static components such as images, CSS and JavaScript files.

Answer 1

To disable browser cache for JSP pages, create a Filter which is mapped on an url-pattern of *.jsp and does basically the following in the doFilter() method:

HttpServletResponse httpResponse = (HttpServletResponse) response;
httpResponse.setHeader("Cache-Control", "no-cache, no-store, must-revalidate"); // HTTP 1.1
httpResponse.setHeader("Pragma", "no-cache"); // HTTP 1.0
httpResponse.setDateHeader("Expires", 0); // Proxies.

This way you don’t need to copypaste this over all JSP pages and clutter them with scriptlets.

To enable browser cache for static components like CSS and JS, put them all in a common folder like /static or /resources and create a Filter which is mapped on an url-pattern of /static/* or /resources/* and does basically the following in the doFilter() method:

httpResponse.setDateHeader("Expires", System.currentTimeMillis() + 604800000L); // 1 week in future.

See also:

• Making sure a web page is not cached, across all browsers.
• Webapplication performance tips and tricks.