org.argeo.api.uuid/src/org/argeo/api/uuid/TypedUuid.java

   1 package org.argeo.api.uuid;
   2
   3 import java.util.Objects;
   4 import java.util.UUID;
   5
   6 /**
   7  * Base class for objects which are explicitly typed, based on the various
   8  * variant 2 (RFC 4122) UUID versions (and variant 6 with {@link GUID}, for
   9  * completion). Such a derivation hierarchy still represents the {@link UUID}
  10  * itself, not the objects, data or concept that it identifies. Just like
  11  * {@link UUID}s, {@link TypedUuid} should be used as identifier, not as base
  12  * class for complex objects. It should rather be seen as a framework to build
  13  * richer IDs, which are strictly compliant with the UUID specifications.
  14  */
  15 public abstract class TypedUuid extends UuidHolder {
  16         private static final long serialVersionUID = APM.SERIAL;
  17
  18         /** Default constructor. */
  19         public TypedUuid(UUID uuid) {
  20                 super(uuid);
  21         }
  22
  23         /**
  24          * Whether this {@link UUID} has no meaning in itself (RFC4122 v3, v4 and v5,
  25          * and Microsoft GUID). Only RFC4122 v1 and v2 can be interpreted.
  26          */
  27         public boolean isOpaque() {
  28                 if (uuid.variant() == 2) {// RFC4122
  29                         return uuid.version() == 4 || uuid.version() == 5 || uuid.version() == 3;
  30                 } else if (uuid.variant() == 6) {// Microsoft
  31                         return true;
  32                 } else {
  33                         return true;
  34                 }
  35         }
  36
  37         /**
  38          * Constructs a {@link TypedUuid} of the most appropriate subtype, based on this
  39          * {@link UUID}. For name based UUIDs, it will return an opaque
  40          * {@link BasicNameUuid}; {@link NameUuid} and {@link BinaryNameUuid} may be
  41          * more useful.
  42          */
  43         public static TypedUuid of(UUID uuid) {
  44                 Objects.requireNonNull(uuid, "UUID cannot be null");
  45                 if (uuid.variant() == 2) {// RFC 4122
  46                         switch (uuid.version()) {
  47                         case 1:
  48                                 return new TimeUuid(uuid);
  49                         case 4:
  50                                 return new RandomUuid(uuid);
  51                         case 3:
  52                         case 5:
  53                                 return new BasicNameUuid(uuid);
  54                         default:
  55                                 throw new IllegalArgumentException("UUIDs with version " + uuid.version() + " are not supported.");
  56                         }
  57                 } else if (uuid.variant() == 6) {// GUID
  58                         return new GUID(uuid);
  59                 } else {
  60                         throw new IllegalArgumentException("UUIDs with variant " + uuid.variant() + " are not supported.");
  61                 }
  62         }
  63
  64 }