Last Modified is a property in the portal.properties file, which is the default configuration file for Sun GlassFish Web Space Server. You can override this property using portal-ext.properties file.
Set the following to true to check last modified date on server side CSS and JavaScript.
last.modified.check=true |
Provide a list of comma-delimited paths that will only be executed when newer than the last modified date. These paths must extend com.liferay.portal.lastmodified.LastModifiedAction.
last.modified.paths=\ /portal/css_cached,\ /portal/javascript_cached |