EJB Deployment descriptor - What is Deployment descriptor?

What is deployment descriptor?

- The deployment descriptor directs a deployment tool to deploy a module or application with specific container options.

- It describes specific configuration requirements that a deployer must resolve.

- XML is used for the syntax of these deployment descriptor files.

- It is a configuration file for an artifact which is deployed to some container/engine.

- It describes how a component, module or application should be deployed.

- The deployment descriptor for the web applications must be called web.xml and should reside in the WEB-INF directory in the web application root.

- The deployment descriptor for the Java EE applications must be named as application.xml and must be placed directly in the META-INF directory at the top level of the application .ear file.

There are two types of deployment descriptors:

1. Java EE deployment descriptors
2. Runtime deployment descriptors