org.d_haven.mpool

Interface Pool

All Known Subinterfaces:

ManagablePool

All Known Implementing Classes:

AbstractPool, FixedSizePool, VariableSizePool

public interface Pool

This interface is to define how a Pool is used. We have determined by using the previous Pool implementations that the Pool marker interface is considered harmful. When generics are introduced in JDK 1.5, this interface will be a prime candidate for those improvements.

It is important to realize that some objects are cheaper to simply allow the garbage collector to take care of them. Therefore, only pool objects that are computationally expensive to create. Prime candidates would be Components, JDBC Connection objects, Socket connections, etc.

The interface is inspired by both the Mutex acquire/release and the structure of the ThreadLocal object. In fact, it would be trivial to implement a "ThreadLocal" pool.

Version:

CVS $Revision: 1.4 $ $Date: 2004/06/21 17:03:46 $

Author:

Berin Loritsch

Method Summary

Modifier and Type	Method and Description
java.lang.Object	acquire() Acquire an instance of the pooled object.
void	addPoolListener(PoolListener listener) Add a pool listener to the pool.
void	release(java.lang.Object pooledObject) Release the instance of the pooled object.
void	removePoolListener(PoolListener listener) Remove a pool listener from the pool.

Method Detail

acquire

java.lang.Object acquire()
                  throws java.lang.Exception

Acquire an instance of the pooled object.

Returns:

the pooled Object instance

Throws:

java.lang.Exception - if the Pool is not able to return an object.

release

void release(java.lang.Object pooledObject)

Release the instance of the pooled object.

Parameters:

pooledObject - The pooled object to release to the pool.

addPoolListener

void addPoolListener(PoolListener listener)

Add a pool listener to the pool. If you add a listener twice it will be notified twice and you will have to remove it twice.

Parameters:

listener - the listener to add.

removePoolListener

void removePoolListener(PoolListener listener)

Remove a pool listener from the pool. If you add a listener twice it will be notified twice and you will have to remove it twice.

Parameters:

listener - the listener to remove