/*-- $Id: NegateFilter.java,v 1.4 2007/11/10 05:29:00 jhunter Exp $ Copyright (C) 2000-2007 Jason Hunter & Brett McLaughlin. 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 disclaimer that follows    these conditions in the documentation and/or other materials    provided with the distribution. 3. The name "JDOM" must not be used to endorse or promote products    derived from this software without prior written permission.  For    written permission, please contact <request_AT_jdom_DOT_org>. 4. Products derived from this software may not be called "JDOM", nor    may "JDOM" appear in their name, without prior written permission    from the JDOM Project Management <request_AT_jdom_DOT_org>. In addition, we request (but do not require) that you include in the end-user documentation provided with the redistribution and/or in the software itself an acknowledgement equivalent to the following:     "This product includes software developed by the      JDOM Project (http://www.jdom.org/)." Alternatively, the acknowledgment may be graphical using the logos available at http://www.jdom.org/images/logos. 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 JDOM AUTHORS OR THE PROJECT 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 the JDOM Project and was originally created by Jason Hunter <jhunter_AT_jdom_DOT_org> and Brett McLaughlin <brett_AT_jdom_DOT_org>.  For more information on the JDOM Project, please see <http://www.jdom.org/>. */package org.jdom.filter;/** * Filter that is the logical <b>negation</b> operation of another filter. * * * @author Bradley S. Huffman * @version $Revision: 1.4 $, $Date: 2007/11/10 05:29:00 $ */final class NegateFilter extends AbstractFilter {    private static final String CVS_ID =       "@(#) $RCSfile: NegateFilter.java,v $ $Revision: 1.4 $ $Date: 2007/11/10 05:29:00 $";    // Underlying filter.    private Filter filter;    /**     * Match if the supplied filter <b>does not</b> match.     *     * @param filter filter to use.     */    public NegateFilter(Filter filter) {        this.filter = filter;    }    public boolean matches(Object obj) {        return !filter.matches(obj);    }    public Filter negate() {        return filter;    }    public boolean equals(Object obj) {        if (this == obj) {            return true;        }        if (obj instanceof NegateFilter) {            return filter.equals(((NegateFilter) obj).filter);        }        return false;    }    public int hashCode() {        return ~filter.hashCode();    }    public String toString() {        return new StringBuffer(64)                   .append("[NegateFilter: ")                   .append(filter.toString())                   .append("]")                   .toString();    }}