利用原子类生成唯一序列号

package com.ezubo.global.util;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.concurrent.atomic.AtomicLong;

/**
 * 利用原子类生成序列号 不适合分布式场景
 * Created by  on 2015-12-29.
 */
public class Generators2 {
    private static AtomicLong no = new AtomicLong(1L);
    private static final String DATE_FORMAT = "yyyyMMddHHmmss";
    private static final SimpleDateFormat SIMPLE_DATE_FORMAT = new SimpleDateFormat(DATE_FORMAT);
    private static String forwardTime = "";

    private Generators2(){
        super();
    }

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