com.intel.bluetooth.WeakVectorFactory Maven / Gradle / Ivy
/**
* BlueCove - Java library for Bluetooth
* Copyright (C) 2006-2007 Vlad Skarzhevskyy
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* @version $Id: WeakVectorFactory.java 1107 2007-10-24 16:30:00Z skarzhevskyy $
*/
package com.intel.bluetooth;
import java.util.Vector;
import java.util.WeakHashMap;
/**
* An entry in a WeakVector will automatically be removed when its key is no longer in ordinary use.
* This class is wrapper above WeakHashMap when available. e.g. on J2SE 1.2 and above
* For IBM J9 MIDP we will use Vector to make application work.
* But connection can't be discarded by the garbage collector.
* @author vlads
*
*/
class WeakVectorFactory {
public static interface WeakVector {
public void addElement(Object obj);
public int size();
public boolean removeElement(Object obj);
public boolean contains(Object elem);
public Object firstElement();
}
public static WeakVector createWeakVector() {
try {
return new WeakVectorOnWeakHashMapImpl();
} catch (Throwable e) {
return new WeakVectorOnVectorImpl();
}
}
private static class WeakVectorOnVectorImpl implements WeakVector {
private Vector vectorImpl;
private WeakVectorOnVectorImpl() {
vectorImpl = new Vector();
}
public void addElement(Object obj) {
vectorImpl.addElement(obj);
}
public boolean contains(Object elem) {
return vectorImpl.contains(elem);
}
public Object firstElement() {
return vectorImpl.firstElement();
}
public boolean removeElement(Object obj) {
return vectorImpl.removeElement(obj);
}
public int size() {
return vectorImpl.size();
}
}
private static class WeakVectorOnWeakHashMapImpl implements WeakVector {
private WeakHashMap mapImpl;
private WeakVectorOnWeakHashMapImpl() {
mapImpl = new WeakHashMap();
}
public void addElement(Object obj) {
mapImpl.put(obj, new Object());
}
public boolean contains(Object elem) {
return mapImpl.containsKey(elem);
}
public Object firstElement() {
return mapImpl.keySet().iterator().next();
}
public boolean removeElement(Object obj) {
return (mapImpl.remove(obj) != null);
}
public int size() {
return mapImpl.size();
}
}
}