Connection management architecture
Note: WebSphere Application Server does not support JDBC 3.0.
The connection management architecture for both relational and procedural access to enterprise information systems (EIS) is based on the J2EE Connector Architecture (JCA) specification. The Connection Manager (CM), which pools and manages connections within an appserver, is capable of managing connections obtained through both resource adapters (RAs) defined by the JCA specification, and DataSources defined by the JDBC 2.0 Extensions Specification.
To make DataSource connections manageable by this CM that works only with RAs, WebSphere Application Server V5.0 provides its own resource adapter. From the CM point of view, JDBC DataSources and JCA connection factories look the same. Users of DataSources do not experience any programmatic or behavioral differences in their applications because of the underlying JCA architecture. JDBC users still configure and use DataSources according to the JDBC programming model.
Applications migrating from previous versions of WebSphere Application Server might experience some behavioral differences because of the change from J2EE 1.2 requirements to J2EE 1.3 requirements. These differences are not related to the adoption of the JCA architecture.
If you have J2EE 1.2 applications using the JDBC API that you wish to run in WebSphere Application Server 5.0, the JDBC CM from V4.0 is still provided as a configuration option. Using this configuration option enables J2EE 1.2 applications to run unaltered. If you migrate a V4.0 application to V5.0, using the V5.0 migration tools, the application automatically uses the V4.0 connection manager after migration. However, EJB 2.0 modules in J2EE 1.3 applications cannot use the JDBC CM from V4.0.
Connection pooling
Connection life cycle
Unshareable and shareable connections
Connection handles
Connections and transactions
Resource adapter
Configuring data access for application clients
Migrating a version 4.0 data access application to version 5.1