Everything an application server offers to the users is accessible by a listener. Basically each listener is assigned a server socket that handles requests placed on the socket it listens on. For example, by default the
admin-listener listens on
0.0.0.0:4848, which means it listens on all available network addresses on port
Because of the diversity of Java EE platform and application servers, different application servers have multiple types of listeners which administrators can use to configure the application server to listen on different port and addresses for handling different set of protocols.
In GlassFish we have three types of listeners and for each type we have one or more instance configured by ...