T - the route category that represents the opposite endpoint of a pooled
connection.E - the category of the pool entry containing a pooled connection.public interface ConnPool<T,E>
java.util.concurrent.Future<E> lease(T route, java.lang.Object state, FutureCallback<E> callback)
route - route of the connection.state - arbitrary object that represents a particular state
(usually a security principal or a unique token identifying
the user whose credentials have been used while establishing the connection).
May be null.callback - operation completion callback.void release(E entry, boolean reusable)
entry - pool entry leased from the poolreusable - flag indicating whether or not the released connection
is in a consistent state and is safe for further use.