单例模式生成订单编号

package com.jeeplus.modules.biz.util;

import java.text.SimpleDateFormat;import java.util.Date;import java.util.Random;

/** * 单例模式 * 生成订单编号 */public class SingletonUtil {    private volatile static  SingletonUtil singletonUtil;    private SingletonUtil(){}    public static SingletonUtil getSingletonUtil(){        if (singletonUtil == null){            synchronized (SingletonUtil.class){                if(singletonUtil==null){                    singletonUtil = new SingletonUtil();                }            }        }        return singletonUtil;    }

/**     * 生成编号     * @param prefix     * @return     */    public String makeOrderNum(String prefix){        SimpleDateFormat simpleDateFormat;        simpleDateFormat = new SimpleDateFormat("yyyyMMddHHmmss");        Date date = new Date();        String str =prefix + "-" + simpleDateFormat.format(date);        Random random = new Random();        int ranNum = (int) (random.nextDouble() * (99999 - 10000 + 1)) + 10000;// 获取5位随机数        System.out.println("生成订单号："+str + ranNum);        return str + ranNum;// 当前时间    }

/**     * 测试     * @param args     */    public static void main(String[] args) {        // 测试多线程调用订单号生成工具        try {            for (int i = 0; i < 100; i++) {                Thread t1 = new Thread(new Runnable() {                    public void run() {                        SingletonUtil makeOrder = new SingletonUtil();                        String prefix="HD";                        makeOrder.makeOrderNum(prefix);                    }                }, "at" + i);                t1.start();

Thread t2 = new Thread(new Runnable() {                    public void run() {                        SingletonUtil makeOrder = new SingletonUtil();                        String prefix="AB";                        makeOrder.makeOrderNum(prefix);                    }                }, "bt" + i);                t2.start();            }        } catch (Exception e) {            e.printStackTrace();        }    }}

原文地址：https://www.cnblogs.com/duanqiao123/p/8717541.html