JavaServer Pages, 3rd Edition

Making a JDBC 1.0 Connection Pool Behave as a JDBC 2.0 Connection Pool

If you can’t find a JDBC 2.0 connection pool implementation for your database, there are plenty of implementations based on JDBC 1.0 available. A popular one is the DBConnectionBroker, available at http://www.javaexchange.com/. Another one, DBCP, is developed by the Jakarta Commons project: http://jakarta.apache.org/commons/index.html and is bundled with Tomcat. In this section I describe a couple of wrapper classes you can use with minimal changes for implementations like these so they can be used in place of a JDBC 2.0 connection pool implementation. This way the JSTL database access actions and other generic database tools can use your wrapped JDBC 1.0 pool, and it’s easy to replace it with a real JDBC 2.0 pool when one becomes available from your database vendor or a third party.

The interaction between the wrapper classes and a connection pool implementation is illustrated in Figure 24-3.

Figure 24-3. A connection pool wrapped with JDBC 2.0 interface classes

The application calls the DataSourceWrapper getConnection( ) method. The DataSourceWrapper obtains a Connection object from its ConnectionPool object (which represents the JDBC 1.0 pool implementation). The ConnectionPool either finds an available Connection in its pool or creates a new one. The DataSourceWrapper creates a new ConnectionWrapper object for ...