Question

Java中这个C＃代码的等价物是什么？

int tick = 0;
tick = Environment.TickCount;

Answer 1

没有标准的方法可以在Java中获得系统的正常运行时间。如果你知道你在类Unix系统上，你可以使用：

Runtime.getRuntime().exec('uptime');

或者您可以阅读系统文件：

new Scanner(new FileInputStream("/proc/uptime")).next();

在某些系统上，这也是System.nanoTime()返回的值，但不保证System.nanoTime()的来源（或者甚至返回值为正）。

如果你想要这个的唯一原因是测量经过的时间，你可以使用System.nanoTime()，或者，如果你想测量经过的挂钟时间（包括在做时间时可能做出的任何调整），使用System.currentTimeMillis()。

Answer 2

正如@TedHopp所提到的，一种可能性是使用System.currentTimeMillis（）。在我的情况下，我希望在几秒钟内“滴答计数”，而不是毫秒。这是我目前正在使用的相应C＃方法的Java版本。

   // Static field used by the tickCountInSeconds() method
   private static long _firstCallTimeSeconds = 0;

...

   /**
    * Method to get an arbitrary constantly increasing time in seconds, i.e., a time in seconds that
    * can be used to compare the relative times of two events, but without having any other meaning.
    *
    * The .Net version of this method uses the Windows "tick count" facility, but since that doesn't
    * exist in Java we fake it by getting the system (Unix-style) time in milliseconds and
    * converting it to seconds. But to avoid the "year 2038 problem" (or to avoid criticism for
    * creating a year 2038 vulnerability) the time of the first call is saved in a static field and
    * subtracted from the returned result.
    */
   private synchronized static int tickCountInSeconds() {
      long currentTimeSeconds = System.currentTimeMillis() / 1000L;
      if (_firstCallTimeSeconds == 0) {
         _firstCallTimeSeconds = currentTimeSeconds;
      }

      return (int)(currentTimeSeconds - _firstCallTimeSeconds);
   }

java中的Environment.tickcount

2 个答案: