唯一值

　　public static Long createID() {
        Random rand = new Random();
        StringBuffer sb = new StringBuffer();
//等待1秒,指定根据时间毫秒数获取13位不重复数字
//        try {
//            Thread.sleep(1);
//        } catch (InterruptedException e) {
//            e.printStackTrace();
//            System.out.println("生成唯一数  createID exception()");
//        } finally {
//            sb.append(System.currentTimeMillis() + "");
//        }
//固定5位随机数
        for (int i = 1; i <= 5; i++) {
            //随机生成1-9自然数
            int randNum = rand.nextInt(9) + 1;
            sb = sb.append(randNum + "");
        }
        return Long.parseLong(System.currentTimeMillis() + String.valueOf(sb));
    }

    public static void main(String[] args) {
//压力测试生成唯一值毫秒数
        long startTime = System.currentTimeMillis();
        for (int i = 0; i < 3000; i++) {
            System.out.println(createID());
        }
        long endTime = System.currentTimeMillis();
        float excTime = (float) (endTime - startTime) / 1000;
        System.out.println("执行时间为：" + excTime + "s");
    }