001/*
002 *  Licensed to the Apache Software Foundation (ASF) under one
003 *  or more contributor license agreements.  See the NOTICE file
004 *  distributed with this work for additional information
005 *  regarding copyright ownership.  The ASF licenses this file
006 *  to you under the Apache License, Version 2.0 (the
007 *  "License"); you may not use this file except in compliance
008 *  with the License.  You may obtain a copy of the License at
009 *  
010 *    http://www.apache.org/licenses/LICENSE-2.0
011 *  
012 *  Unless required by applicable law or agreed to in writing,
013 *  software distributed under the License is distributed on an
014 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 *  KIND, either express or implied.  See the License for the
016 *  specific language governing permissions and limitations
017 *  under the License. 
018 *  
019 */
020package org.apache.directory.api.ldap.model.filter;
021
022
023/**
024 * An empty class used for the (ObjectClass=*) node.
025 *
026 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
027 * @version $Rev$, $Date$
028 */
029public final class ObjectClassNode extends AbstractExprNode
030{
031    /** A static instance of this node */
032    public static final ExprNode OBJECT_CLASS_NODE = new ObjectClassNode();
033
034
035    /**
036     * Creates a new instance of ObjectClassNode.
037     */
038    private ObjectClassNode()
039    {
040        super( AssertionType.OBJECTCLASS );
041    }
042
043
044    /**
045     * {@inheritDoc}
046     * 
047     * This implementation always returns true.
048     */
049    @Override
050    public boolean isLeaf()
051    {
052        return true;
053    }
054
055
056    /**
057     * {@inheritDoc}
058     * 
059     * This implementation always returns null.
060     */
061    @Override
062    public Object accept( FilterVisitor visitor )
063    {
064        return null;
065    }
066
067
068    /**
069     * {@inheritDoc}
070     */
071    @Override
072    public String toString()
073    {
074        return "All";
075    }
076}