tk.mybatis.mapper.version.VersionUtil Maven / Gradle / Ivy
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/*
* The MIT License (MIT)
*
* Copyright (c) 2014-2017 [email protected]
*
* 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 tk.mybatis.mapper.version;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.locks.ReentrantLock;
/**
* @author liuzh
* @since 3.5.0
*/
public class VersionUtil {
private static final Map, NextVersion> CACHE = new ConcurrentHashMap, NextVersion>();
private static final ReentrantLock LOCK = new ReentrantLock();
/**
* 获取下一个版本
*
* @param nextVersionClass
* @param current
* @return
* @throws VersionException
*/
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);
}
}
}