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 19:26:29 +0200 (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 }