Shuyi Chen | d7955ce | 2013-05-22 14:51:55 -0700 | [diff] [blame] | 1 | // Copyright (c) 1999-2004 Brian Wellington (bwelling@xbill.org) |
| 2 | |
| 3 | package org.xbill.DNS; |
| 4 | |
| 5 | /** |
| 6 | * Constants and functions relating to DNS classes. This is called DClass |
| 7 | * to avoid confusion with Class. |
| 8 | * |
| 9 | * @author Brian Wellington |
| 10 | */ |
| 11 | |
| 12 | public final class DClass { |
| 13 | |
| 14 | /** Internet */ |
| 15 | public static final int IN = 1; |
| 16 | |
| 17 | /** Chaos network (MIT) */ |
| 18 | public static final int CH = 3; |
| 19 | |
| 20 | /** Chaos network (MIT, alternate name) */ |
| 21 | public static final int CHAOS = 3; |
| 22 | |
| 23 | /** Hesiod name server (MIT) */ |
| 24 | public static final int HS = 4; |
| 25 | |
| 26 | /** Hesiod name server (MIT, alternate name) */ |
| 27 | public static final int HESIOD = 4; |
| 28 | |
| 29 | /** Special value used in dynamic update messages */ |
| 30 | public static final int NONE = 254; |
| 31 | |
| 32 | /** Matches any class */ |
| 33 | public static final int ANY = 255; |
| 34 | |
| 35 | private static class DClassMnemonic extends Mnemonic { |
| 36 | public |
| 37 | DClassMnemonic() { |
| 38 | super("DClass", CASE_UPPER); |
| 39 | setPrefix("CLASS"); |
| 40 | } |
| 41 | |
| 42 | public void |
| 43 | check(int val) { |
| 44 | DClass.check(val); |
| 45 | } |
| 46 | } |
| 47 | |
| 48 | private static Mnemonic classes = new DClassMnemonic(); |
| 49 | |
| 50 | static { |
| 51 | classes.add(IN, "IN"); |
| 52 | classes.add(CH, "CH"); |
| 53 | classes.addAlias(CH, "CHAOS"); |
| 54 | classes.add(HS, "HS"); |
| 55 | classes.addAlias(HS, "HESIOD"); |
| 56 | classes.add(NONE, "NONE"); |
| 57 | classes.add(ANY, "ANY"); |
| 58 | } |
| 59 | |
| 60 | private |
| 61 | DClass() {} |
| 62 | |
| 63 | /** |
| 64 | * Checks that a numeric DClass is valid. |
| 65 | * @throws InvalidDClassException The class is out of range. |
| 66 | */ |
| 67 | public static void |
| 68 | check(int i) { |
| 69 | if (i < 0 || i > 0xFFFF) |
| 70 | throw new InvalidDClassException(i); |
| 71 | } |
| 72 | |
| 73 | /** |
| 74 | * Converts a numeric DClass into a String |
| 75 | * @return The canonical string representation of the class |
| 76 | * @throws InvalidDClassException The class is out of range. |
| 77 | */ |
| 78 | public static String |
| 79 | string(int i) { |
| 80 | return classes.getText(i); |
| 81 | } |
| 82 | |
| 83 | /** |
| 84 | * Converts a String representation of a DClass into its numeric value |
| 85 | * @return The class code, or -1 on error. |
| 86 | */ |
| 87 | public static int |
| 88 | value(String s) { |
| 89 | return classes.getValue(s); |
| 90 | } |
| 91 | |
| 92 | } |