/**  Copyright (c) 2001 Sun Microsystems, Inc.  All rights*  reserved.**  Redistribution and use in source and binary forms, with or without*  modification, are permitted provided that the following conditions*  are met:**  1. Redistributions of source code must retain the above copyright*  notice, this list of conditions and the following disclaimer.**  2. Redistributions in binary form must reproduce the above copyright*  notice, this list of conditions and the following disclaimer in*  the documentation and/or other materials provided with the*  distribution.**  3. The end-user documentation included with the redistribution,*  if any, must include the following acknowledgment:*  "This product includes software developed by the*  Sun Microsystems, Inc. for Project JXTA."*  Alternately, this acknowledgment may appear in the software itself,*  if and wherever such third-party acknowledgments normally appear.**  4. The groups "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA"*  must not be used to endorse or promote products derived from this*  software without prior written permission. For written*  permission, please contact Project JXTA at http://www.jxta.org.**  5. Products derived from this software may not be called "JXTA",*  nor may "JXTA" appear in their group, without prior written*  permission of Sun.**  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED*  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES*  OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE*  DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR*  ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,*  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT*  LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF*  USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND*  ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,*  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT*  OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF*  SUCH DAMAGE.*  ====================================================================**  This software consists of voluntary contributions made by many*  individuals on behalf of Project JXTA.  For more*  information on Project JXTA, please see*  <http://www.jxta.org/>.**  This license is based on the BSD license adopted by the Apache Foundation.**  $Id: Bans.java,v 1.3 2006/06/12 20:45:22 nano Exp $*/package net.jxta.myjxta.directive.util;import java.util.ArrayList;import java.util.Collections;import java.util.List;import net.jxta.myjxta.dialog.DialogMessage;/** * * @version $Id: Bans.java,v 1.3 2006/06/12 20:45:22 nano Exp $ * * @author james todd [gonzo at jxta dot org] */public class Bans {    private static Bans instance = null;    private List<String> bans = null;    /**     * Returns the handle to this singleton instance.     */    public static synchronized Bans getInstance() {        if (instance == null) {            instance = new Bans();        }        return instance;    }    /**     * Returns the <code>List</code> of peer ids that have been banned in this session.     */    public List getBans() {        return this.bans != null ?               this.bans : Collections.EMPTY_LIST;    }    /**     * Returns true if the originator of the supplied DialogMessage is banned, and false otherwise.     */    public boolean isBanned (DialogMessage msg) {        if (msg == null) {            return false;        }        return isBanned(msg.getOriginator());    }    /**     * Returns true if the supplied peer id is banned, and false otherwise.     */    public boolean isBanned (String peer) {        if (peer == null) {            return false;        }        return getBans().contains(peer);    }    /**     * Adds the supplied peer to the list of banned peers.     */    public void addBan(String peer) {        peer = peer != null ? peer.trim() : peer;        if (peer != null) {            if (this.bans == null) {                this.bans = new ArrayList<String>();            }            if (! this.bans.contains(peer)) {                this.bans.add(peer);            }        }    }    /**     * Adds the supplied peer <code>List</code> to the list of banned peers.     *      * @param bans A <code>List</code> of <code>Strings</code>.  Each element in the list is a peer id.     */    public void addBans(List<String> bans) {        this.bans.addAll(bans);    }    /**     * Removes the supplied peer from the list of banned peers.     */    public void removeBan(String peer) {        peer = peer != null ? peer.trim() : null;        if (peer != null &&            this.bans != null) {            this.bans.remove(peer);            if (this.bans.size() == 0) {                this.bans = null;            }        }    }    /**     * Removes the supplied peer <code>List</code> from the list of banned peers.     *      * @param bans A <code>List</code> of <code>Strings</code>.  Each element in the list is a peer id.     */    public void removeBans(List bans) {        this.bans.removeAll(bans);    }    /**     * Removes all peers <code>List</code> from the list of banned peers.     */    public synchronized void clearBans() {        if (this.bans != null) {            this.bans.clear();            this.bans = null;        }    }    /**     * Limits the instantiation of this class.     */    protected Bans() {        super();    }}