Application: gvSIG desktop

/**

 * gvSIG. Desktop Geographic Information System.

 *

 * Copyright (C) 2007-2013 gvSIG Association.

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 3

 * of the License, or (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,

 * MA  02110-1301, USA.

 *

 * For any additional information, do not hesitate to contact us

 * at info AT gvsig.com, or visit our website www.gvsig.com.

 */

/* CVS MESSAGES:

*

* $Id: Queue.java 29631 2009-06-29 16:56:19Z jpiera $

* $Log$

* Revision 1.1  2006-03-14 19:23:07  azabala

* *** empty log message ***

*

*

*/

package org.gvsig.utils;

import java.util.Vector;

        /**

         * A simple FIFO queue class which causes the calling thread to wait if the

         * queue is empty and notifies threads that are waiting when it is not

         * empty.

         * 

         * @author Anil V (akv@eng.sun.com)

         */

        public class Queue {

            private Vector vector = new Vector();

            /**

                 * Put the object into the queue.

                 * 

                 * @param object

                 *            the object to be appended to the queue.

                 */

            public synchronized void put(Object object) {

                vector.addElement(object);

                notify();

            }

            /**

                 * Pull the first object out of the queue. Wait if the queue is empty.

                 */

            public synchronized Object pull() {

                while (isEmpty())

                    try {

                        wait();

                    } catch (InterruptedException ex) {

                    }

                return get();

            }

            /**

                 * Get the first object out of the queue. Return null if the queue is

                 * empty.

                 */

            public synchronized Object get() {

                Object object = peek();

                if (object != null)

                    vector.removeElementAt(0);

                return object;

            }

            /**

                 * Peek to see if something is available.

                 */

            public Object peek() {

                if (isEmpty())

                    return null;

                return vector.elementAt(0);

            }

            /**

                 * Is the queue empty?

                 */

            public boolean isEmpty() {

                return vector.isEmpty();

            }

            /**

                 * How many elements are there in this queue?

                 */

            public int size() {

                return vector.size();

            }

        }