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.codec.search;
021    
022    
023    import java.nio.BufferOverflowException;
024    import java.nio.ByteBuffer;
025    
026    import org.apache.directory.shared.asn1.ber.tlv.TLV;
027    import org.apache.directory.shared.asn1.codec.EncoderException;
028    import org.apache.directory.shared.ldap.codec.LdapConstants;
029    import org.apache.directory.shared.ldap.util.StringTools;
030    
031    
032    /**
033     * Object to store the filter. A filter is seen as a tree with a root.
034     * 
035     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
036     * @version $Rev: 664290 $, $Date: 2008-06-07 08:28:06 +0200 (Sam, 07 jui 2008) $, 
037     */
038    public class PresentFilter extends Filter
039    {
040        // ~ Instance fields
041        // ----------------------------------------------------------------------------
042    
043        /** The attribute description. */
044        private String attributeDescription;
045        
046        /** Temporary storage for attribute description bytes */
047        private byte[] attributeDescriptionBytes; 
048    
049    
050        // ~ Constructors
051        // -------------------------------------------------------------------------------
052    
053        /**
054         * The constructor.
055         */
056        public PresentFilter( int tlvId )
057        {
058            super( tlvId );
059        }
060        
061        
062        /**
063         * The constructor.
064         */
065        public PresentFilter()
066        {
067            super();
068        }
069    
070    
071        // ~ Methods
072        // ------------------------------------------------------------------------------------
073    
074        /**
075         * Get the attribute
076         * 
077         * @return Returns the attributeDescription.
078         */
079        public String getAttributeDescription()
080        {
081            return attributeDescription;
082        }
083    
084    
085        /**
086         * Set the attributeDescription
087         * 
088         * @param attributeDescription The attributeDescription to set.
089         */
090        public void setAttributeDescription( String attributeDescription )
091        {
092            this.attributeDescription = attributeDescription;
093        }
094    
095    
096        /**
097         * Compute the PresentFilter length 
098         * PresentFilter : 
099         * 0x87 L1 present
100         * 
101         * Length(PresentFilter) = Length(0x87) + Length(super.computeLength()) +
102         *      super.computeLength()
103         */
104        public int computeLength()
105        {
106            attributeDescriptionBytes = StringTools.getBytesUtf8( attributeDescription );
107            return 1 + TLV.getNbBytes( attributeDescriptionBytes.length ) + attributeDescriptionBytes.length;
108        }
109    
110    
111        /**
112         * Encode the PresentFilter message to a PDU. PresentFilter : 0x87 LL
113         * attributeDescription
114         * 
115         * @param buffer The buffer where to put the PDU
116         * @return The PDU.
117         */
118        public ByteBuffer encode( ByteBuffer buffer ) throws EncoderException
119        {
120            if ( buffer == null )
121            {
122                throw new EncoderException( "Cannot put a PDU in a null buffer !" );
123            }
124    
125            try
126            {
127                // The PresentFilter Tag
128                buffer.put( ( byte ) LdapConstants.PRESENT_FILTER_TAG );
129                buffer.put( TLV.getBytes( attributeDescriptionBytes.length ) );
130                buffer.put( attributeDescriptionBytes );
131            }
132            catch ( BufferOverflowException boe )
133            {
134                throw new EncoderException( "The PDU buffer size is too small !" );
135            }
136    
137            super.encode( buffer );
138    
139            return buffer;
140        }
141    
142    
143        /**
144         * Return a string compliant with RFC 2254 representing a Present filter
145         * 
146         * @return The Present filter string
147         */
148        public String toString()
149        {
150    
151            StringBuffer sb = new StringBuffer();
152    
153            sb.append( attributeDescription ).append( "=*" );
154    
155            return sb.toString();
156        }
157    }