java - 17 :42:55. 7385459 如何在java中制作这个日期格式

Question

2013-11-20T17:42:55.7385459如何在java中制作这种日期格式

我不知道这意味着什么，最后 7 个字符是什么..yyyy-MM-dd'T'HH:mm:ss.7385459

Answer 1

看看here在System.nanoTime();调用时，它提供纳秒级的精度(但不一定是纳秒级的精度)。 警告 作为一个例子，您可以尝试(但这可能是一个坏主意，因为 nanoTime() 不是为了获取挂钟时间) -

// It would probably be a better idea to use HH:mm:ss.SSS, and the nanoseconds.
// Not to imply that that's a good idea, just better then this (but would add even more digits).
private static final SimpleDateFormat sdf = new SimpleDateFormat("HH:mm:ss");
// This isn't really nanosecond accurate, and is probably a bad idea.
private static String getNanoTime() {
  long start = System.nanoTime();
  StringBuilder sb = new StringBuilder();
  Calendar c = Calendar.getInstance();
  sb.append(sdf.format(c.getTime()));
  sb.append(".");
  sb.append(System.nanoTime() - start);
  return sb.toString();
}

public static void main(String[] args) {
  System.out.println(getNanoTime());
}