to have a connection pool you have at least two options:
-use a library that create the pool (you create it in your application and your application manage the pool) and use this pool to retrieve the connections. -use applications server to create and manage the pool.
in first solution you download the library and use it to create a pool according to its manual, apache DBCP is a good option. and here is a link to almost all open source connection pooling library that you can use for your connection pooling . http://java-source.net/open-source/connection-pools