J2SE Naming Services

A JNDI name is a user-friendly name for an object. These names are bound to their objects by the naming and directory service that is provided by a J2SE server. Because J2SE components access this service through the JNDI API, an object’s user-friendly name is its JNDI name. For instance, the JNDI name of the Oracle database can be jdbc/Oracle. When it starts up, Sun Java System Web Server reads information from configuration file and automatically adds JNDI database names to the name space.

The application component’s naming environment is a mechanism that allows customization of the application component’s business logic during deployment or assembly. Use of the application component’s environment allows the application component to be customized without the need to access or change the application component’s source code.

A J2SE container implements the Web application component’s environment, and provides it to the application component instance as a JNDI naming context. The application component’s environment is used as follows:

• The Web application component’s business methods access the environment using the JNDI interfaces. The application component provider declares in the deployment descriptor all the environment entries that the application component expects to be provided in its environment at runtime.

• The container provides an implementation of the JNDI naming context that stores the application component environment. The container also provides the tools that allow the deployer to create and manage the environment of each application component.

• A deployer uses the tools provided by the container to initialize the environment entries that are declared in the application component’s deployment descriptor. The deployer can set and modify the values of the environment entries.

• The container makes the environment naming context available to the application component instances at runtime. The application component’s instances use the JNDI interfaces to obtain the values of the environment entries.

Each application component defines its own set of environment entries. All instances of an application component within the same container share the same environment entries. Application component instances are not allowed to modify the environment at runtime.