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     */
020    package org.apache.directory.shared.ldap.filter;
021    
022    import org.apache.directory.shared.i18n.I18n;
023    
024    
025    /**
026     * Node used for the application of arbitrary predicates on return candidates.
027     * Applies dynamic and programatic criteria for the selection of candidates for
028     * return. Nodes of this type may be introduced into the filter expression to
029     * provided the opportunity to constrain the search further without altering the
030     * search algorithm.
031     * 
032     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
033     * @version $Revision: 912436 $
034     */
035    public abstract class AssertionNode extends AbstractExprNode
036    {
037        /** The assertion or predicate to apply */
038        private final Assertion assertion;
039    
040        /** Description of assertion for polish printouts */
041        private final String desc;
042    
043    
044        // ------------------------------------------------------------------------
045        // C O N S T R U C T O R S
046        // ------------------------------------------------------------------------
047    
048    
049        /**
050         * Creates an AssertionNode using an arbitrary candidate assertion.
051         * 
052         * @param assertion the arbitrary selection logic.
053         */
054        public AssertionNode( Assertion assertion )
055        {
056            this( assertion, "ASSERTION" );
057        }
058    
059    
060        /**
061         * Creates an AssertionNode using an arbitrary candidate assertion with a
062         * descriptions used for filter AST walker dumps.
063         * 
064         * @param assertion the arbitrary selection logic.
065         * @param desc the printout representation for filter prints.
066         */
067        public AssertionNode( Assertion assertion, String desc )
068        {
069            super( AssertionType.ASSERTION );
070            this.desc = desc;
071            this.assertion = assertion;
072    
073            /*
074             * We never want this node to ever make it to the point of becoming a
075             * candidate for use in an enumeration so we set the scan count to the
076             * maximum value.
077             */
078            set( "count", Long.MAX_VALUE );
079        }
080    
081        /**
082         * Makes a full clone in new memory space of the current node and children
083         * 
084         * @return the clone
085         */
086        @Override public ExprNode clone()
087        {
088            return (ExprNode)super.clone();
089        }
090        
091    
092    
093        /**
094         * Gets the Assertion used by this assertion node.
095         * 
096         * @return the assertion used by this node
097         */
098        public Assertion getAssertion()
099        {
100            return assertion;
101        }
102    
103    
104        // ------------------------------------------------------------------------
105        // A B S T R A C T M E T H O D I M P L E M E N T A T I O N S
106        // ------------------------------------------------------------------------
107    
108        
109        /**
110         * Always returns true since an AssertionNode has no children.
111         * 
112         * @see org.apache.directory.shared.ldap.filter.ExprNode#isLeaf()
113         * @return true if the node is a leaf,false otherwise
114         */
115        public boolean isLeaf()
116        {
117            return true;
118        }
119    
120    
121        /**
122         * @see ExprNode#printRefinementToBuffer(StringBuilder) 
123         */
124        public StringBuilder printRefinementToBuffer( StringBuilder buf ) throws UnsupportedOperationException
125        {
126            throw new UnsupportedOperationException( I18n.err( I18n.ERR_04145 ) );
127        }
128    
129    
130        /**
131         * @see Object#hashCode()
132         * @return the instance's hash code 
133         */
134        public int hashCode()
135        {
136            int h = 37;
137            
138            h = h*17 + super.hashCode();
139            h = h*17 + ( assertion != null ? assertion.hashCode() : 0 );
140            h = h*17 + ( desc != null ? desc.hashCode() : 0 );
141            
142            return h;
143        }
144    
145    
146        /**
147         * @see org.apache.directory.shared.ldap.filter.ExprNode#accept(
148         *      org.apache.directory.shared.ldap.filter.FilterVisitor)
149         */
150        public Object accept( FilterVisitor visitor )
151        {
152            return visitor.visit( this );
153        }
154    
155    
156        /**
157         * @see Object#toString
158         * @return A string representing the AndNode
159         */
160        public String toString()
161        {
162            StringBuilder buf = new StringBuilder();
163            
164            buf.append( "(@" );
165            buf.append( desc );
166            buf.append( super.toString() );
167            buf.append( ')' );
168            
169            return buf.toString();
170        }
171    }