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.i18n.I18n;
029    import org.apache.directory.shared.ldap.codec.LdapConstants;
030    import org.apache.directory.shared.ldap.util.StringTools;
031    
032    
033    /**
034     * Object to store the filter. A filter is seen as a tree with a root.
035     * 
036     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
037     * @version $Rev: 912399 $, $Date: 2010-02-21 21:52:31 +0100 (Sun, 21 Feb 2010) $, 
038     */
039    public class PresentFilter extends Filter
040    {
041        // ~ Instance fields
042        // ----------------------------------------------------------------------------
043    
044        /** The attribute description. */
045        private String attributeDescription;
046        
047        /** Temporary storage for attribute description bytes */
048        private byte[] attributeDescriptionBytes; 
049    
050    
051        // ~ Constructors
052        // -------------------------------------------------------------------------------
053    
054        /**
055         * The constructor.
056         */
057        public PresentFilter( int tlvId )
058        {
059            super( tlvId );
060        }
061        
062        
063        /**
064         * The constructor.
065         */
066        public PresentFilter()
067        {
068            super();
069        }
070    
071    
072        // ~ Methods
073        // ------------------------------------------------------------------------------------
074    
075        /**
076         * Get the attribute
077         * 
078         * @return Returns the attributeDescription.
079         */
080        public String getAttributeDescription()
081        {
082            return attributeDescription;
083        }
084    
085    
086        /**
087         * Set the attributeDescription
088         * 
089         * @param attributeDescription The attributeDescription to set.
090         */
091        public void setAttributeDescription( String attributeDescription )
092        {
093            this.attributeDescription = attributeDescription;
094        }
095    
096    
097        /**
098         * Compute the PresentFilter length 
099         * PresentFilter : 
100         * 0x87 L1 present
101         * 
102         * Length(PresentFilter) = Length(0x87) + Length(super.computeLength()) +
103         *      super.computeLength()
104         */
105        public int computeLength()
106        {
107            attributeDescriptionBytes = StringTools.getBytesUtf8( attributeDescription );
108            return 1 + TLV.getNbBytes( attributeDescriptionBytes.length ) + attributeDescriptionBytes.length;
109        }
110    
111    
112        /**
113         * Encode the PresentFilter message to a PDU. PresentFilter : 0x87 LL
114         * attributeDescription
115         * 
116         * @param buffer The buffer where to put the PDU
117         * @return The PDU.
118         */
119        public ByteBuffer encode( ByteBuffer buffer ) throws EncoderException
120        {
121            if ( buffer == null )
122            {
123                throw new EncoderException( I18n.err( I18n.ERR_04023 ) );
124            }
125    
126            try
127            {
128                // The PresentFilter Tag
129                buffer.put( ( byte ) LdapConstants.PRESENT_FILTER_TAG );
130                buffer.put( TLV.getBytes( attributeDescriptionBytes.length ) );
131                buffer.put( attributeDescriptionBytes );
132            }
133            catch ( BufferOverflowException boe )
134            {
135                throw new EncoderException( I18n.err( I18n.ERR_04005 ) );
136            }
137    
138            super.encode( buffer );
139    
140            return buffer;
141        }
142    
143    
144        /**
145         * Return a string compliant with RFC 2254 representing a Present filter
146         * 
147         * @return The Present filter string
148         */
149        public String toString()
150        {
151    
152            StringBuffer sb = new StringBuffer();
153    
154            sb.append( attributeDescription ).append( "=*" );
155    
156            return sb.toString();
157        }
158    }