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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  
21  package org.apache.directory.server.ntp.messages;
22  
23  
24  import java.util.Arrays;
25  import java.util.Collections;
26  import java.util.List;
27  
28  
29  /**
30   * Stratum: This is a eight-bit unsigned integer indicating the stratum
31   * level of the local clock, with values defined as follows:
32   *
33   *    Stratum  Meaning
34   *    ----------------------------------------------
35   *    0        unspecified or unavailable
36   *    1        primary reference (e.g., radio clock)
37   *    2-15     secondary reference (via NTP or SNTP)
38   *    16-255   reserved
39   * 
40   * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
41   * @version $Rev: 586763 $, $Date: 2007-10-20 19:26:29 +0200 (Sa, 20 Okt 2007) $
42   */
43  public final class StratumType implements Comparable<StratumType>
44  {
45      /**
46       * Constant for the "Unspecified or unavailable" stratum type.
47       */
48      public static final StratumType UNSPECIFIED = new StratumType( 0, "Unspecified or unavailable." );
49  
50      /**
51       * Constant for the "Primary reference" stratum type.
52       */
53      public static final StratumType PRIMARY_REFERENCE = new StratumType( 1, "Primary reference." );
54  
55      /**
56       * Constant for the "Secondary reference" stratum type.
57       */
58      public static final StratumType SECONDARY_REFERENCE = new StratumType( 2, "Secondary reference." );
59  
60      /**
61       * Array for building a List of VALUES.
62       */
63      private static final StratumType[] values =
64          { UNSPECIFIED, PRIMARY_REFERENCE, SECONDARY_REFERENCE };
65  
66      /**
67       * A list of all the stratum type constants.
68       */
69      public static final List<StratumType> VALUES = Collections.unmodifiableList( Arrays.asList( values ) );
70  
71      /**
72       * The name of the stratum type.
73       */
74      private final String name;
75  
76      /**
77       * The value/code for the stratum type.
78       */
79      private final int ordinal;
80  
81  
82      /**
83       * Private constructor prevents construction outside of this class.
84       */
85      private StratumType( int ordinal, String name )
86      {
87          this.ordinal = ordinal;
88          this.name = name;
89      }
90  
91  
92      /**
93       * Returns the stratum type when specified by its ordinal.
94       *
95       * @param type
96       * @return The stratum type.
97       */
98      public static StratumType getTypeByOrdinal( int type )
99      {
100         for ( int ii = 0; ii < values.length; ii++ )
101         {
102             if ( values[ii].ordinal == type )
103             {
104                 return values[ii];
105             }
106         }
107 
108         return UNSPECIFIED;
109     }
110 
111 
112     /**
113      * Returns the number associated with this stratum type.
114      *
115      * @return The stratum type ordinal.
116      */
117     public int getOrdinal()
118     {
119         return ordinal;
120     }
121 
122 
123     public int compareTo( StratumType that )
124     {
125         return ordinal - that.ordinal;
126     }
127 
128 
129     public String toString()
130     {
131         return name;
132     }
133 }