001    /* BinaryRefAddr.java -- RefAddr that uses a byte array as content.
002       Copyright (C) 2001 Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    package javax.naming;
039    
040    import gnu.java.lang.CPStringBuilder;
041    
042    import java.util.Arrays;
043    
044    /**
045     * RefAddr that uses a byte array as content.
046     * This can be used to reference objects that can only be represented as
047     * byte arrays.
048     *
049     * @see Reference
050     * @since 1.3
051     * @author Mark Wielaard (mark@klomp.org)
052     */
053    public class BinaryRefAddr extends RefAddr
054    {
055      static final long serialVersionUID = -3415254970957330361L;
056    
057      /**
058       * The possibly null content of this RefAddr.
059       * Set by the constructor and returned by getContent.
060       */
061      private final byte[] buf;
062    
063      /**
064       * Contructs a new BinaryRefAddr with the given type and content.
065       * The complete content of the byte array is copied to a new array.
066       */
067      public BinaryRefAddr (String addrType, byte[] buf)
068      {
069        this(addrType, buf, 0, buf.length);
070      }
071    
072      /**
073       * Contructs a new BinaryRefAddr with the given type and the content
074       * taken from the given byte array.
075       * The content of the byte array is copied to a new array.
076       */
077      public BinaryRefAddr (String addrType, byte[] buf, int off, int length)
078      {
079        super(addrType);
080        this.buf = new byte[length];
081        System.arraycopy(buf, off, this.buf, 0, length);
082      }
083    
084      /**
085       * Returns the byte array contents as given to the constructor.
086       * The returned byte array is shared with this object and other callers.
087       * Changing the content of the buffer is discouraged and should only be
088       * done when the byte array is locked.
089       */
090      public Object getContent ()
091      {
092        return buf;
093      }
094    
095      /**
096       * Checks if the object is a BinaryRefAddr with the same type and with the
097       * same bytes in the content.
098       *
099       * @return true if the given object is an instance of BinaryRefAddr,
100       *         the addrType is the same as this addrType and the bytes of the
101       *         content are the same.
102       */
103      public boolean equals(Object o)
104      {
105        if (o instanceof BinaryRefAddr)
106          {
107            BinaryRefAddr refAddr = (BinaryRefAddr) o;
108            if (this.getType().equals(refAddr.getType()))
109            {
110              byte[] c1 = (byte[]) this.getContent();
111              byte[] c2 = (byte[]) refAddr.getContent();
112              return Arrays.equals(c1, c2);
113            }
114          }
115        return false;
116      }
117    
118      /**
119       * Returns the hashCode which is the hasCode of the String returned by
120       * <code>getType()</code> plus the hashCode of the byte array returned by
121       * <code>getContent</code>. The hashCode of the byte array is calculated
122       * by taking the xor of all the bytes in the array, or zero when there are
123       * no bytes in the array.
124       */
125      public int hashCode()
126      {
127        int result = 0;
128        byte[] b = (byte[]) getContent();
129        for (int i=0; i < b.length; i++)
130          result = result^b[i];
131    
132        return getType().hashCode() + result;
133      }
134    
135      private static char[] hex = {'0', '1', '2', '3', '4', '5', '6', '7',
136                                   '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
137      /**
138       * Returns a String representation of the RefAddr. Only the first 32 bytes
139       * of the content are added as hex encoded characters.
140       * Should only be used for debugging purposes.
141       */
142      public String toString()
143      {
144        CPStringBuilder sb = new CPStringBuilder("[RefAddr type: ");
145        sb.append(getType());
146        sb.append(" content: 0x");
147        byte[] b = (byte[]) getContent();
148        for (int i=0; i < b.length && i < 32; i++)
149          {
150            sb.append(hex[(b[i]&0xf0)>>4]);
151            sb.append(hex[b[i]&0x0f]);
152          }
153        if (b.length > 32)
154          sb.append("...");
155        sb.append("]");
156        return sb.toString();
157      }
158    }