org.aoju.bus.mapper.version.DefaultNextVersion Maven / Gradle / Ivy
/*********************************************************************************
* *
* The MIT License (MIT) *
* *
* Copyright (c) 2015-2022 aoju.org mybatis.io and other contributors. *
* *
* Permission is hereby granted, free of charge, to any person obtaining a copy *
* of this software and associated documentation files (the "Software"), to deal *
* in the Software without restriction, including without limitation the rights *
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell *
* copies of the Software, and to permit persons to whom the Software is *
* furnished to do so, subject to the following conditions: *
* *
* The above copyright notice and this permission notice shall be included in *
* all copies or substantial portions of the Software. *
* *
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR *
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, *
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE *
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER *
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, *
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN *
* THE SOFTWARE. *
* *
********************************************************************************/
package org.aoju.bus.mapper.version;
import org.aoju.bus.core.exception.VersionException;
import java.sql.Timestamp;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.locks.ReentrantLock;
/**
* 默认版本实现
*
* @author Kimi Liu
* @since Java 17+
*/
public class DefaultNextVersion implements NextVersion {
private static final Map, NextVersion> CACHE = new ConcurrentHashMap<>();
private static final ReentrantLock LOCK = new ReentrantLock();
/**
* 获取下一个版本
*
* @param nextVersionClass 下个版本
* @param current 当前版本
* @return the object
* @throws VersionException 异常
*/
public static Object nextVersion(Class nextVersionClass, Object current) throws VersionException {
try {
NextVersion nextVersion;
if (CACHE.containsKey(nextVersionClass)) {
nextVersion = CACHE.get(nextVersionClass);
} else {
LOCK.lock();
try {
if (!CACHE.containsKey(nextVersionClass)) {
CACHE.put(nextVersionClass, nextVersionClass.newInstance());
}
nextVersion = CACHE.get(nextVersionClass);
} finally {
LOCK.unlock();
}
}
return nextVersion.nextVersion(current);
} catch (Exception e) {
throw new VersionException("获取下一个版本号失败!", e);
}
}
@Override
public Object nextVersion(Object current) throws VersionException {
if (current == null) {
throw new VersionException("当前版本号为空!");
}
if (current instanceof Integer) {
return (Integer) current + 1;
} else if (current instanceof Long) {
return (Long) current + 1L;
} else if (current instanceof Timestamp) {
return new Timestamp(System.currentTimeMillis());
} else {
throw new VersionException("默认的 NextVersion 只支持 Integer, Long 和 java.sql.Timestamp 类型的版本号，如果有需要请自行扩展!");
}
}
}