JRubyRack

NOTE: contents of this page are being moved to https://github.com/jruby/jruby-rack/wiki.

Servlet Filter

JRuby-Rack's main mode of operation is as a servlet filter. This allows requests for static content to pass through and be served by the application server. Dynamic requests only happen for URLs that don't have a corresponding file, much like many Ruby applications expect.

Goldspike-compatible Servlet

JRuby-Rack includes a stub RailsServlet and recognizes many of Goldspike's context parameters (e.g., pool size configuration), making it interchangeable with Goldspike, for convenience of migration. One caveat is that static content is served by Rack, which requires acquisition of a JRuby runtime. Your throughput with static files will be much lower than when JRuby-Rack is configured as a servlet filter. You have been warned!

Servlet environment integration

• Servlet context is accessible to any application both through the global variable $servlet_context and the Rack environment variable java.servlet_context.
• Servlet request object is available in the Rack environment via the key java.servlet_request.
• Servlet request attributes are passed through to the Rack environment.
• Rack environment variables and headers can be overridden by servlet request attributes.
• Java servlet sessions are used as the default session store for both Rails and Merb. Session attributes with String keys and String, numeric, boolean, or java object values are automatically copied to the servlet session for you.

JRuby Runtime Management

JRuby runtime management and pooling is done automatically by the framework. In the case of Rails, runtimes are pooled. For Merb and other Rack applications, a single runtime is created and shared for every request.