01 /*
02 *
03 * Licensed to the Apache Software Foundation (ASF) under one
04 * or more contributor license agreements. See the NOTICE file
05 * distributed with this work for additional information
06 * regarding copyright ownership. The ASF licenses this file
07 * to you under the Apache License, Version 2.0 (the
08 * "License"); you may not use this file except in compliance
09 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing,
14 * software distributed under the License is distributed on an
15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16 * KIND, either express or implied. See the License for the
17 * specific language governing permissions and limitations
18 * under the License.
19 *
20 */
21 package org.apache.qpid.util;
22
23 import java.nio.ByteBuffer;
24 import java.util.UUID;
25
26
27 /**
28 * NameUUIDGen
29 *
30 */
31
32 public final class NameUUIDGen implements UUIDGen
33 {
34
35 private static final int WIDTH = 8;
36
37 final private byte[] seed;
38 final private ByteBuffer seedBuf;
39 private long counter;
40
41 public NameUUIDGen()
42 {
43 String namespace = UUID.randomUUID().toString();
44 this.seed = new byte[namespace.length() + WIDTH];
45 for (int i = WIDTH; i < seed.length; i++)
46 {
47 seed[i] = (byte) namespace.charAt(i - WIDTH);
48 }
49 this.seedBuf = ByteBuffer.wrap(seed);
50 this.counter = 0;
51 }
52
53 public UUID generate()
54 {
55 seedBuf.putLong(0, counter++);
56 return UUID.nameUUIDFromBytes(seed);
57 }
58
59 }
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