java对代码进行性能分析

使用Instant对象来完成

关键代码:

获取当前时间

Instant now = Instant.now();

获取当前时间距离1970-01-01 00:00:00的秒数

now.getEpochSecond()

完整测试代码

        Scanner sc = new Scanner(System.in);
        Instant now1 = Instant.now();
        System.out.println("请随便输个东西:");
        //输入间隔的时间模拟程序运行        
        int pr = sc.nextInt();

        Instant now2 = Instant.now();
        System.out.println(now1.getEpochSecond());
        System.out.println(now2.getEpochSecond());

        long carryTime = now2.getEpochSecond() - now1.getEpochSecond();
        System.out.println(carryTime);

运行可得到程序运行的秒数