J2EE Services

The J2EE platform services simplify application programming and allow components and applications to be customized at deployment time to use resources available in the deployment environment. This section gives a brief overview of the J2EE platform naming, deployment, transaction, and security services.The J2EE platform provides services for applications, including:

• Naming -A naming and directory service binds objects to names. A J2EE application can locate an object by looking up its Java Naming and Directory Interface (JNDI) name.

• Security - The Java Authorization Contract for Containers (JACC) is a set of security contracts defined for the J2EE containers. Based on the client’s identity, containers can restrict access to the container’s resources and services.

• Transaction management - A transaction is an indivisible unit of work. For example, transferring funds between bank accounts is a transaction. A transaction management service ensures that a transaction is either completed, or is rolled back.

• Message Service - Applications hosted on separate systems can communicate with each other by exchanging messages using the Java™ Message Service (JMS). JMS is an integral part of the J2EE platform and simplifies the task of integrating heterogeneous enterprise applications.