org.openl.ie.tools.ReusableFactory Maven / Gradle / Ivy
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package org.openl.ie.tools;
///////////////////////////////////////////////////////////////////////////////
/*
* Copyright Exigen Group 1998, 1999, 2000
* 320 Amboy Ave., Metuchen, NJ, 08840, USA, www.exigengroup.com
*
* The copyright to the computer program(s) herein
* is the property of Exigen Group, USA. All rights reserved.
* The program(s) may be used and/or copied only with
* the written permission of Exigen Group
* or in accordance with the terms and conditions
* stipulated in the agreement/contract under which
* the program(s) have been supplied.
*/
///////////////////////////////////////////////////////////////////////////////
import java.io.Serializable;
import java.util.Enumeration;
import java.util.Vector;
/**
* An abstract implementation of the factory for reusable objects.
*
* Any concrete factory should implement the method: createNewElement(). This method returns a new uninitialized object
* for the conctete factory.
*
* @see Reusable
*/
// "implements serializable" was added by Eugeny Tseitlin 18.06.2003
public abstract class ReusableFactory implements Serializable {
/**
* All created factories.
*/
protected static final Vector _allFactories = new Vector();
protected FastStack _reusables;
protected int _element_counter;
/**
* Performs cleanup for all factories.
*/
public static void cleanAll() {
Enumeration it = _allFactories.elements();
while (it.hasMoreElements()) {
((ReusableFactory) it.nextElement()).cleanUp();
}
}
/**
* Default constructor initializes this factory and registeres this factory in all factories.
*/
public ReusableFactory() {
_reusables = new FastStack();
_element_counter = 0;
register();
}
/**
* Performs cleanup for this factory.
*/
public void cleanUp() {
_reusables = new FastStack();
_element_counter = 0;
}
/**
* Creates new uninitialized object for this factory.
*/
abstract protected Reusable createNewElement();
/**
* Returns the unused object to the factory.
*/
public final synchronized void freeElement(Reusable element) {
_reusables.push(element);
}
/**
* Returns next the uninitialized object for this factory. If there are unused objects one of them is returned.
* Otherwise new object is created and returned.
*/
public final synchronized Object getElement() {
Reusable result;
_element_counter++;
if (_reusables.empty()) {
result = createNewElement();
result.setFactory(this);
} else {
result = (Reusable) _reusables.pop();
}
return result;
}
/**
* Registers this factory in all factories.
*/
void register() {
_allFactories.addElement(this);
}
} // ~ReusableFactory