org.springframework.util.SimpleIdGenerator Maven / Gradle / Ivy
/*
* Copyright 2002-2015 the original author or authors.
*
* Licensed 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.springframework.util;
import java.util.UUID;
import java.util.concurrent.atomic.AtomicLong;
/**
* A simple {@link IdGenerator} that starts at 1 and increments by 1 with each call.
*
* @author Rossen Stoyanchev
* @since 4.1.5
*/
public class SimpleIdGenerator implements IdGenerator {
private final AtomicLong mostSigBits = new AtomicLong(0);
private final AtomicLong leastSigBits = new AtomicLong(0);
@Override
public UUID generateId() {
long leastSigBits = this.leastSigBits.incrementAndGet();
if (leastSigBits == 0) {
this.mostSigBits.incrementAndGet();
}
return new UUID(this.mostSigBits.get(), leastSigBits);
}
}