/*
* Copyright 1999-2017 Alibaba Group Holding Ltd.
*
* 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 com.alibaba.druid.spring;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import org.springframework.transaction.annotation.Propagation;
import org.springframework.transaction.annotation.Transactional;
public class SequenceService implements SequenceServiceMBean, ISequenceService {
private Lock lock = new ReentrantLock();
private ISequenceDao dao;
private String name = "druid-spring-test";
private String seed;
private AtomicInteger increment = new AtomicInteger();
public ISequenceDao getDao() {
return dao;
}
public void setDao(ISequenceDao dao) {
this.dao = dao;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getSeed() {
return this.seed;
}
@Transactional(propagation = Propagation.NOT_SUPPORTED)
public long nextValue() {
if (seed == null) {
init();
}
int value = increment.getAndIncrement();
String text = seed + "9" + Integer.toString(value);
return Long.parseLong(text);
}
@Transactional(propagation = Propagation.NOT_SUPPORTED)
public void init() {
lock.lock();
try {
this.seed = nextSeed();
} finally {
lock.unlock();
}
}
@Transactional(propagation = Propagation.NOT_SUPPORTED)
public String nextSeed() {
lock.lock();
try {
for (; ; ) {
int value = dao.getValue(name);
if (dao.compareAndSet(name, value + 1, value)) {
if (value == 0) {
return "";
} else {
return Integer.toString(value, 9);
}
}
}
} finally {
lock.unlock();
}
}
}