Deployment is an important step in the lifecycle of a Java EE application. So much so that most organizations have a deployer role dedicated to this step. The deployer will configure the application for the environment in which it is being deployed and will identify the resources that the application needs and map them to the correct references in the application. The process of mapping the actual resources to the references in the application is done by means of the Java EE deployment descriptors and server-specific deployment plans. We will now go into the details of these files.
A deployment descriptor is an XML file that describes the Java EE module. It lists the Java EE components that make up the module, and defines the environment for these components. Java EE components have access to a naming service called JNDI, which is used to decouple the component from the resources and other components that it uses. The component will access...