Deployment descriptor
A deployment descriptor is a configuration file in XML format . In the Java Platform, Enterprise Edition environment , this configuration file describes the specific deployment process and the information required for this, such as:
- Name, class and interfaces of an Enterprise JavaBean (EJB)
- Information about whether certain methods may or must be called under certain types of transactions
- References to resources that the container must provide to the bean, e.g. B. Data Sources
- References to other EJBs or web services
- optionally the definition of the endpoints of web services as which the EJBs are to be offered
- For entity beans with Container Managed Persistence, the name of their abstract schema and the definition of their persistent fields and relationships between them; can also queries for specific search methods (so-called finders are defined)
In addition to these standardized properties, EJB containers define additional, container-specific properties. At the time of installation, these properties can be specified in different ways, depending on the container - in Java properties files , XML files or interactively. The information can be evaluated during provision or at runtime.
In Java web applications , the deployment descriptor must have the name web.xml and be located in the WEB-INF subdirectory of the web application's root directory. In Java EE applications, the deployment descriptor must have the name application.xml and be located in the META-INF subdirectory of the Enterprise Archives ("EAR file").