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    JBoss MicroKernel Definitions




    This page defines the terminology used in the MicroKernel design.




    Some terms can be used interchangeably, this page serves to give more exact definitions to remove confusion.




    • Kernel - a generic term for the services that make up the JBoss MicroKernel.


    • POJO/bean - the object under management by the kernel.


    • Service - a POJO that has a lifecycle.


    • IOC (inversion of control) - the POJO relies on the kernel/container to inject the relevent object in a usable state.


    • Injection - the idea that a POJO declares it requires an Object of a certain type and leaves it to external processing to provide the Object.


    • Lifecycle - routines that provide runtime processing beyond basic configuration/injection. e.g. binding sockets


    • Configuration - information used to configure a POJO, including attribute values, injections, etc.


    • Descriptor - metadata about a POJO, e.g. what configuration is required


    • Profile - defines which POJOs should be instantiated and which Services should be started and when.


    • Container - a wrapper for a POJO that adds extra behaviour (aspects). Also, when in a non-JBoss environment, the container where the JBoss kernel is deployed.


    • Deployer - code that parses configuration files to create POJOs, metadata, config, etc.


    • System - a general area of the application - e.g. JMS


    • Subsystem - a specific part of a system, e.g. JMS persistence


    • Dependency - where a POJO, classes, binding uses another (e.g. an EJB depends upon a jndi binding)


    • Subservice - where one service is made up of other services (e.g. an EJB has a cache)


    • VFS (virtual file system) - frees deployers from the need to worry about the physical deployment