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1   /*
2    *  Licensed to the Apache Software Foundation (ASF) under one
3    *  or more contributor license agreements.  See the NOTICE file
4    *  distributed with this work for additional information
5    *  regarding copyright ownership.  The ASF licenses this file
6    *  to you under the Apache License, Version 2.0 (the
7    *  "License"); you may not use this file except in compliance
8    *  with the License.  You may obtain a copy of the License at
9    *  
10   *    http://www.apache.org/licenses/LICENSE-2.0
11   *  
12   *  Unless required by applicable law or agreed to in writing,
13   *  software distributed under the License is distributed on an
14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   *  KIND, either express or implied.  See the License for the
16   *  specific language governing permissions and limitations
17   *  under the License. 
18   *  
19   */
20  package org.apache.directory.server.core.partition.impl.btree.jdbm;
21  
22  
23  import java.io.IOException;
24  
25  import jdbm.helper.Serializer;
26  
27  
28  /**
29   * A custom String serializer to [de]serialize Strings.
30   *
31   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
32   * @version $Rev$, $Date$
33   */
34  public class StringSerializer implements Serializer
35  {
36      private static final long serialVersionUID = -173163945773783649L;
37  
38  
39      /* (non-Javadoc)
40       * @see jdbm.helper.Serializer#deserialize(byte[])
41       */
42      public Object deserialize( byte[] bites ) throws IOException
43      {
44          if ( bites.length == 0 )
45          {
46              return "";
47          }
48  
49          char[] strchars = new char[bites.length >> 1];
50          for ( int ii = 0, jj = 0; ii < strchars.length; ii++, jj = ii << 1 )
51          {
52              int ch = bites[jj] << 8 & 0x0000FF00;
53              ch |= bites[jj+1] & 0x000000FF;
54              strchars[ii] = ( char ) ch;
55          }
56          return new String( strchars );
57      }
58  
59  
60      private static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
61      
62      /* (non-Javadoc)
63       * @see jdbm.helper.Serializer#serialize(java.lang.Object)
64       */
65      public byte[] serialize( Object str ) throws IOException
66      {
67          if ( ( ( String ) str ).length() == 0 )
68          {
69              return EMPTY_BYTE_ARRAY;
70          }
71          
72          char[] strchars = ( ( String ) str ).toCharArray();
73          byte[] bites = new byte[strchars.length<<1];
74          for ( int ii = 0, jj = 0; ii < strchars.length; ii++, jj = ii << 1 )
75          {
76              bites[jj] = ( byte ) ( strchars[ii] >> 8 & 0x00FF );
77              bites[jj+1] = ( byte ) ( strchars[ii] & 0x00FF );
78          }
79          
80          return bites;
81      }
82  }