为了在Java中实现这一点，应该使用哪些类型?

答:长

public class Stream {
    public long startTime;
    public long endTime;

    public long getDuration() {
        return endTime - startTime;
    }
    // I  would add
    public void start() {
        startTime = System.currentTimeMillis();
    }
    public void stop() {
         endTime = System.currentTimeMillis();
     }
}

用法:

  Stream s = .... 

  s.start();

  // do something for a while 

  s.stop();

  s.getDuration(); // gives the elapsed time in milliseconds. 

这是我对你第一个问题的直接回答。

最后一个“注释”，我建议你使用Joda Time。它包含一个适合您需要的间隔类。

如果目的只是将粗略的计时信息打印到程序日志中，那么Java项目的简单解决方案不是编写自己的秒表或计时器类，而是使用Apache Commons Lang中的org.apache.commons.lang.time.StopWatch类。

final StopWatch stopwatch = new StopWatch();
stopwatch.start();
LOGGER.debug("Starting long calculations: {}", stopwatch);
...
LOGGER.debug("Time after key part of calcuation: {}", stopwatch);
...
LOGGER.debug("Finished calculating {}", stopwatch);

我建立了一个格式化函数，基于我偷来的东西。我需要一种方法来“分析”日志消息中的内容，所以我需要一个固定长度的持续时间消息。

public static String GetElapsed(long aInitialTime, long aEndTime, boolean aIncludeMillis)
{
  StringBuffer elapsed = new StringBuffer();

  Map<String, Long> units = new HashMap<String, Long>();

  long milliseconds = aEndTime - aInitialTime;

  long seconds = milliseconds / 1000;
  long minutes = milliseconds / (60 * 1000);
  long hours = milliseconds / (60 * 60 * 1000);
  long days = milliseconds / (24 * 60 * 60 * 1000);

  units.put("milliseconds", milliseconds);
  units.put("seconds", seconds);
  units.put("minutes", minutes);
  units.put("hours", hours);
  units.put("days", days);

  if (days > 0)
  {
    long leftoverHours = hours % 24;
    units.put("hours", leftoverHours);
  }

  if (hours > 0)
  {
    long leftoeverMinutes = minutes % 60;
    units.put("minutes", leftoeverMinutes);
  }

  if (minutes > 0)
  {
    long leftoverSeconds = seconds % 60;
    units.put("seconds", leftoverSeconds);
  }

  if (seconds > 0)
  {
    long leftoverMilliseconds = milliseconds % 1000;
    units.put("milliseconds", leftoverMilliseconds);
  }

  elapsed.append(PrependZeroIfNeeded(units.get("days")) + " days ")
      .append(PrependZeroIfNeeded(units.get("hours")) + " hours ")
      .append(PrependZeroIfNeeded(units.get("minutes")) + " minutes ")
      .append(PrependZeroIfNeeded(units.get("seconds")) + " seconds ")
      .append(PrependZeroIfNeeded(units.get("milliseconds")) + " ms");

  return elapsed.toString();

}

private static String PrependZeroIfNeeded(long aValue)
{
  return aValue < 10 ? "0" + aValue : Long.toString(aValue);
}

和一个测试类:

import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

import junit.framework.TestCase;

public class TimeUtilsTest extends TestCase
{

  public void testGetElapsed()
  {
    long start = System.currentTimeMillis();
    GregorianCalendar calendar = (GregorianCalendar) Calendar.getInstance();
    calendar.setTime(new Date(start));

    calendar.add(Calendar.MILLISECOND, 610);
    calendar.add(Calendar.SECOND, 35);
    calendar.add(Calendar.MINUTE, 5);
    calendar.add(Calendar.DAY_OF_YEAR, 5);

    long end = calendar.getTimeInMillis();

    assertEquals("05 days 00 hours 05 minutes 35 seconds 610 ms", TimeUtils.GetElapsed(start, end, true));

  }

}

如果您正在编写一个必须处理持续时间的应用程序，那么请查看Joda-Time，它有专门处理持续时间、间隔和周期的类。你的getDuration()方法看起来可以返回一个Joda-Time Interval:

DateTime start = new DateTime(2004, 12, 25, 0, 0, 0, 0);
DateTime end = new DateTime(2005, 1, 1, 0, 0, 0, 0);

public Interval getInterval() {
    Interval interval = new Interval(start, end);
}

值得注意的是

System.currentTimeMillis() has only millisecond accuracy at best. At worth its can be 16 ms on some windows systems. It has a lower cost that alternatives < 200 ns. System.nanoTime() is only micro-second accurate on most systems and can jump on windows systems by 100 microseconds (i.e sometimes it not as accurate as it appears) Calendar is a very expensive way to calculate time. (i can think of apart from XMLGregorianCalendar) Sometimes its the most appropriate solution but be aware you should only time long intervals.

如果您从System.currentTimeMillis()获取时间戳，那么您的时间变量应该是长变量。