com.yuweix.kuafu.sequence.base.AbstractSequence Maven / Gradle / Ivy
package com.yuweix.kuafu.sequence.base;
import com.yuweix.kuafu.sequence.bean.SequenceHolder;
import com.yuweix.kuafu.sequence.dao.SequenceDao;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
/**
* @author yuwei
*/
public abstract class AbstractSequence implements Sequence {
protected final Lock lock = new ReentrantLock();
protected volatile SequenceHolder sequenceHolder;
@SeqField(isDao = true)
protected SequenceDao sequenceDao;
@SeqField(isName = true)
protected String name;
@SeqField(isMinValue = true)
protected long minValue;
public AbstractSequence() {
}
@PostConstruct
public void init() {
synchronized(this) {
sequenceDao.ensure(name, minValue);
}
}
@PreDestroy
public void destroy() {
}
@Override
public long next() {
ensureSequenceHolder();
return nextVal();
}
protected abstract long nextVal();
private void ensureSequenceHolder() {
if (sequenceHolder != null) {
return;
}
lock.lock();
try {
if (sequenceHolder == null) {
sequenceHolder = sequenceDao.nextRange(name);
}
} finally {
lock.unlock();
}
}
public void setSequenceDao(SequenceDao sequenceDao) {
this.sequenceDao = sequenceDao;
}
public void setName(String name) {
this.name = name;
}
public void setMinValue(long minValue) {
this.minValue = minValue;
}
}