$PLUGINS_SDK_HOME folder there is a
hooks directory. We can create a hook there to change Liferay's out-of-the-box JSP files, thus updating the UI.
A hook application is like a portlet application. The story behind the hook is like this: Previously developers could write their own code to update Liferay's core features in its extension environment. This incurs difficulties when Liferay is upgraded to a new version—you have to check which file has been changed and how you can put in your update code. To facilitate customization along Liferay upgrade, the Liferay people introduced the hook feature. Now you can modify Liferay UI with a JSP file in a hook application. When you deploy the hook application, ...