This is the folder that will contain all your sources and configuration files (except those related to the web application). Upon creating of the ext environment several important files will be placed in its subdirectories. The most significant are:
/ext/ext-ejb/classes/portal-ext.properties:
this file can be used to override the values of the properties in
the portal.properties configuration file that
ships with Liferay Portal.
/ext/ext-ejb/classes/system-ext.properties:
this file can be used to override the values of the properties in
the system.properties configuration file that
ships with Liferay Portal.
/ext/ext-ejb/classes/content/Language-ext.properties:
this file can be used to add you're own internationalized text
messages or to override the messages that ship with Liferay Portal.
You can add variations for other languages using the Java convention
for message bundles. For example the translation to Spanish should
be named Language-ext_es.properties.
Run ant deploy from /ext/ext-ejb to compile your source and to deploy your classes to the expanded EAR in your specified application server's deployment directory.