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
021 package org.apache.directory.server.ntp.messages;
022
023
024 import java.util.Arrays;
025 import java.util.Collections;
026 import java.util.List;
027
028
029 /**
030 * Stratum: This is a eight-bit unsigned integer indicating the stratum
031 * level of the local clock, with values defined as follows:
032 *
033 * Stratum Meaning
034 * ----------------------------------------------
035 * 0 unspecified or unavailable
036 * 1 primary reference (e.g., radio clock)
037 * 2-15 secondary reference (via NTP or SNTP)
038 * 16-255 reserved
039 *
040 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
041 * @version $Rev: 586763 $, $Date: 2007-10-20 20:26:29 +0300 (Sat, 20 Oct 2007) $
042 */
043 public final class StratumType implements Comparable<StratumType>
044 {
045 /**
046 * Constant for the "Unspecified or unavailable" stratum type.
047 */
048 public static final StratumType UNSPECIFIED = new StratumType( 0, "Unspecified or unavailable." );
049
050 /**
051 * Constant for the "Primary reference" stratum type.
052 */
053 public static final StratumType PRIMARY_REFERENCE = new StratumType( 1, "Primary reference." );
054
055 /**
056 * Constant for the "Secondary reference" stratum type.
057 */
058 public static final StratumType SECONDARY_REFERENCE = new StratumType( 2, "Secondary reference." );
059
060 /**
061 * Array for building a List of VALUES.
062 */
063 private static final StratumType[] values =
064 { UNSPECIFIED, PRIMARY_REFERENCE, SECONDARY_REFERENCE };
065
066 /**
067 * A list of all the stratum type constants.
068 */
069 public static final List<StratumType> VALUES = Collections.unmodifiableList( Arrays.asList( values ) );
070
071 /**
072 * The name of the stratum type.
073 */
074 private final String name;
075
076 /**
077 * The value/code for the stratum type.
078 */
079 private final int ordinal;
080
081
082 /**
083 * Private constructor prevents construction outside of this class.
084 */
085 private StratumType( int ordinal, String name )
086 {
087 this.ordinal = ordinal;
088 this.name = name;
089 }
090
091
092 /**
093 * Returns the stratum type when specified by its ordinal.
094 *
095 * @param type
096 * @return The stratum type.
097 */
098 public static StratumType getTypeByOrdinal( int type )
099 {
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 }