On the J2EE platform, an external system is called a resource. For example, a database management system is a JDBC resource. Each resource is uniquely identified and by its Java Naming and Directory Interface (JNDI) name. Applications access external systems through the following APIs and components:
Java Database Connectivity (JDBC) - A database management system (DBMS) provides facilities for storing, organizing, and retrieving data. Most business applications store data in relational databases, which applications access via JDBC. The Application Server includes the PointBase DBMS for use sample applications and application development and prototyping, though it is not suitable for deployment. The Application Server provides certified JDBC drivers for connecting to major relational databases. These drivers are suitable for deployment.
Java Message Service - Messaging is a method of communication between software components or applications. A messaging client sends messages to, and receives messages from, any other client via a messaging provider that implements the Java Messaging Service (JMS) API. The Application Server includes a high-performance JMS broker, the Sun Java System Message Queue. The Platform Edition of Application Server includes the free Platform Edition of Message Queue. Application Server Enterprise Edition includes Message Queue Enterprise Edition, that supports clustering and failover.
J2EE Connectors - The J2EE Connector architecture enables integrating J2EE applications and existing Enterprise Information Systems (EIS). An application accesses an EIS through a portable J2EE component called a connector or resource adapter, analogous to using JDBC driver to access an RDBMS. Resource adapters are distributed as standalone Resource Adapter Archive (RAR) modules or included in J2EE application archives. As RARs, they are deployed like other J2EE components. The Application Server includes evaluation resource adapters that integrate with popular EIS.