1 /** 2 * 3 */ 4 package javax.jmdns.impl.constants; 5 6 import java.util.logging.Level; 7 import java.util.logging.Logger; 8 9 /** 10 * DNS Record Class 11 * 12 * @author Arthur van Hoff, Jeff Sonstein, Werner Randelshofer, Pierre Frisch, Rick Blair 13 */ 14 public enum DNSRecordClass { 15 /** 16 * 17 */ 18 CLASS_UNKNOWN("?", 0), 19 /** 20 * static final Internet 21 */ 22 CLASS_IN("in", 1), 23 /** 24 * CSNET 25 */ 26 CLASS_CS("cs", 2), 27 /** 28 * CHAOS 29 */ 30 CLASS_CH("ch", 3), 31 /** 32 * Hesiod 33 */ 34 CLASS_HS("hs", 4), 35 /** 36 * Used in DNS UPDATE [RFC 2136] 37 */ 38 CLASS_NONE("none", 254), 39 /** 40 * Not a DNS class, but a DNS query class, meaning "all classes" 41 */ 42 CLASS_ANY("any", 255); 43 44 private static Logger logger = Logger.getLogger(DNSRecordClass.class.getName()); 45 46 /** 47 * Multicast DNS uses the bottom 15 bits to identify the record class...<br/> 48 * Except for pseudo records like OPT. 49 */ 50 public static final int CLASS_MASK = 0x7FFF; 51 52 /** 53 * For answers the top bit indicates that all other cached records are now invalid.<br/> 54 * For questions it indicates that we should send a unicast response. 55 */ 56 public static final int CLASS_UNIQUE = 0x8000; 57 58 /** 59 * 60 */ 61 public static final boolean UNIQUE = true; 62 63 /** 64 * 65 */ 66 public static final boolean NOT_UNIQUE = false; 67 68 private final String _externalName; 69 70 private final int _index; 71 DNSRecordClass(String name, int index)72 DNSRecordClass(String name, int index) { 73 _externalName = name; 74 _index = index; 75 } 76 77 /** 78 * Return the string representation of this type 79 * 80 * @return String 81 */ externalName()82 public String externalName() { 83 return _externalName; 84 } 85 86 /** 87 * Return the numeric value of this type 88 * 89 * @return String 90 */ indexValue()91 public int indexValue() { 92 return _index; 93 } 94 95 /** 96 * Checks if the class is unique 97 * 98 * @param index 99 * @return <code>true</code> is the class is unique, <code>false</code> otherwise. 100 */ isUnique(int index)101 public boolean isUnique(int index) { 102 return (this != CLASS_UNKNOWN) && ((index & CLASS_UNIQUE) != 0); 103 } 104 105 /** 106 * @param name 107 * @return class for name 108 */ classForName(String name)109 public static DNSRecordClass classForName(String name) { 110 if (name != null) { 111 String aName = name.toLowerCase(); 112 for (DNSRecordClass aClass : DNSRecordClass.values()) { 113 if (aClass._externalName.equals(aName)) return aClass; 114 } 115 } 116 logger.log(Level.WARNING, "Could not find record class for name: " + name); 117 return CLASS_UNKNOWN; 118 } 119 120 /** 121 * @param index 122 * @return class for name 123 */ classForIndex(int index)124 public static DNSRecordClass classForIndex(int index) { 125 int maskedIndex = index & CLASS_MASK; 126 for (DNSRecordClass aClass : DNSRecordClass.values()) { 127 if (aClass._index == maskedIndex) return aClass; 128 } 129 logger.log(Level.WARNING, "Could not find record class for index: " + index); 130 return CLASS_UNKNOWN; 131 } 132 133 @Override toString()134 public String toString() { 135 return this.name() + " index " + this.indexValue(); 136 } 137 138 } 139