/** * <p>The microkernel core of the server is a simple, flexible, nested * container framework defined in this package. </p> * <p> The container model consists of  three primary participants:<br> * </p> * <ul> * <li><strong>Service</strong> - A well-known Java object defined by a * Java interface. Code running in the server should be organized into * services that perform logical (and limited) blocks of work. These * services can then be exposed as a Java interface and obtained using the * ServiceLookup service. Although most services will be local to the * container, some may use RMI, web services, XMPP, or other remote * procedure call technologies to provide services across the network.<br> * </li> * <li><strong>Module </strong>- The smallest server deployment unit. A * module has a well-defined life cycle that is managed by its hosting * container. A module may contain zero or more services and client code * that accesses these services. Modules can be deployed and configured * individually, allowing the easy implementation of server plugins and * on the fly reconfiguration of the server.<br> * </li> * <li><strong>Container </strong>- A special module that hosts server * modules including other containers. Hosting involves life cycle * management of child modules, configuration of child modules, and * providing access to shared resources. Containers also provide their own * configurable security managers and custom classloaders that extend the * classpath to automatically include module classes and jar files located * in well defined locations (e.g. similar to WEB-INF/lib and * WEB-INF/classes in a J2EE web-app/WAR).</li> * </ul> * <p>The nesting nature of containers allows a tree-like server * architecture with a root 'bootstrap container' with core modules, and * child containers with their own modules. Child containers by default * inherit and extend the bootstrap container's classpath and services * while being protected from implementation details of any modules, * containers, or services in layers above them. In some cases, child * containers may have restricted views or access to upper levels of the * tree (e.g. a user plug-in container that allows users to add arbitrary * server extensions).<br> * </p> */ package org.jivesoftware.openfire.container;