org.apache.qpid.util.NameUUIDGen Maven / Gradle / Ivy
/*
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*
*/
package org.apache.qpid.util;
import java.nio.ByteBuffer;
import java.util.UUID;
/**
* NameUUIDGen
*
*/
public final class NameUUIDGen implements UUIDGen
{
private static final int WIDTH = 8;
final private byte[] seed;
final private ByteBuffer seedBuf;
private long counter;
public NameUUIDGen()
{
String namespace = UUID.randomUUID().toString();
this.seed = new byte[namespace.length() + WIDTH];
for (int i = WIDTH; i < seed.length; i++)
{
seed[i] = (byte) namespace.charAt(i - WIDTH);
}
this.seedBuf = ByteBuffer.wrap(seed);
this.counter = 0;
}
public UUID generate()
{
seedBuf.putLong(0, counter++);
return UUID.nameUUIDFromBytes(seed);
}
}