Use a leading slash on the ServletContext getResource() and getResourceAsStream() requests

This rule flags calls to the ServletContext.getResource() and ServletContext.getResourceAsStream() methods where it cannot easily be determined if the String value passed on the method contains a leading slash (/) as required by the Servlet V2.x specification.

Previous versions of WebSphere Application Server ignored the missing '/' and prepended it automatically, but WebSphere Application Server V6.0 enforces more strict compliance. If the String passed does not contain a leading '/', a java.net.MalformedURLException will result at run time.

The web container custom property prependSlashToResource can be set to force the old behavior. If this property is set to true, then the web container will prepend the leading '/' to any getResource requests.