Question

I am creating a JDBC connection pool resource for GlassFish, using the server’s Admin Console.

One of the fields on the page to create the pool is labeled ‘Resource Type’. This field has four possible values: javax.sql.DataSource, javax.sql.XADataSource, javax.sql.ConnectionPoolDataSource and javax.sql.Driver, but the help text for the Create JDBC connection pool ‘wizard’ does not have much info about the advantages and disadvantages of these choices.

When prompted to pick a resource type which should I choose?

I am going to connect to a local MySQL server. It would be nice to get an explanation of the differences between the choices in the drop-down as well.

Answer 1

Below are the scenarios where you would need each of the resource types listed. Hope this helps.

DataSource
DataSource A DataSource object is a factory for Connection objects. When using simple DataSource, appserver uses its own pooling instead of native.

ConnectionPoolDataSource
A ConnectionPoolDataSource object is a factory for PooledConnection objects. ConnectionPoolDataSource is used to give access to PooledConnection which implements native pooling by JDBC driver. In this case application server can implement connections pooling using this native interface. Please refer to Java API to know what a PooledConnection is…A ConnectionPoolDataSource can use a third party implementation for pooling – as far as I know for Tomcat, for instance, DBCP connection pooling is used.

XADataSource
You need an XADataSource if you want to execute a Distributed Transaction. You should use XADataSource instead of DataSource if the application

• Uses the Java Transaction API (JTA)
• Includes multiple database updates within a single transaction
• Accesses multiple resources, such as a database and the Java Messaging Service (JMS), during a transaction