The DBCP Component

   Many Jakarta projects support interaction with a relational database.
   Creating a new connection for each user can be time consuming (often
   requiring multiple seconds of clock time), in order to perform a
   database transaction that might take milliseconds. Opening a
   connection per user can be unfeasible in a publicly-hosted Internet
   application where the number of simultaneous users can be very large.
   Accordingly, developers often wish to share a "pool" of open
   connections between all of the application's current users. The number
   of users actually performing a request at any given time is usually a
   very small percentage of the total number of active users, and during
   request processing is the only time that a database connection is
   required. The application itself logs into the DBMS, and handles any
   user account issues internally.
   There are several Database Connection Pools already available, both
   within Jakarta products and elsewhere. This Commons package provides
   an opportunity to coordinate the efforts required to create and
   maintain an efficient, feature-rich package under the ASF license.
   The commons-dbcp package relies on code in the commons-pool package to
   provide the underlying object pool mechanisms that it utilizes.

WWW: https://commons.apache.org/dbcp/