利用锁机制生成唯一序列号

package com.ezubo.global.util;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/**
 * 利用锁机制 不适用于分布式场景
 * Created by  on 2015-12-29.
 */
public class Generator3 {
    private static Lock lock = new ReentrantLock();
    private static final String DATE_FORMAT = "yyyyMMddHHmmss";
    private static final SimpleDateFormat SIMPLE_DATE_FORMAT = new SimpleDateFormat(DATE_FORMAT);
    private static String forwardTime = "";
    private static Long no = 1L;

    private Generator3(){
        super();
    }

    /**
     * 生成序列号
     * @param prefix
     * @return
     */
    public static String getSeqNo(String prefix){
        lock.lock();
        try{
            String pfix = prefix == null ? "" : prefix;
            String currentTime = SIMPLE_DATE_FORMAT.format(new Date());
            if(!currentTime.equals(forwardTime)){
                no = 1L;
            }
            String serializeNo = FormatUtil.leftpad(no++ , "00000000");
            forwardTime = currentTime;
            return pfix + currentTime + serializeNo;
        }finally {
            lock.unlock();
        }
    }
}