Apache Commons Pool 2 - Pooling implementation for Java objects

 The Apache Commons Pool library provides an object-pooling API and a number
 of object pool implementations. Version 2 of Apache Commons Pool contains
 a completely re-written pooling implementation compared to the 1.x series.
 In addition to performance and scalability improvements, version 2 includes
 robust instance tracking and pool monitoring. Version 2 requires Java 6
 or higher.