java - 使用可变运行时间估计剩余时间

Question

我有一个 Java 项目正在抓取大量 HTML，我想显示剩余时间的估计值。

我想我可以在每个循环的开始和结束时获取时间（以毫秒为单位），然后减去以获得运行的总时间。然后我想我确切地知道我需要跑多少次，所以我可以乘以它来获得总的估计时间。

然后对于剩余的估计时间，我可以保持运行总时间并从总估计时间中减去。

问题是我的输出似乎是负数......？

当前页面++；long timeend = System.currentTimeMillis();

            // Calculate Time
            long runtime = timestart - timeend;
            long timetotal = 0;
            timetotal = timetotal + runtime;
            long averagetime = timetotal / CurrentPage;
            long timeestimated = averagetime * totalpages;
            long timeremaining = timeestimated -timetotal;
            
            
            String RunTime= String.format("%d min, %d sec", TimeUnit.MILLISECONDS.toMinutes(runtime), TimeUnit.MILLISECONDS.toSeconds(runtime));
            String AverageTime=String.format("%d min, %d sec", TimeUnit.MILLISECONDS.toMinutes(averagetime), TimeUnit.MILLISECONDS.toSeconds(averagetime));
            String TimeEstimated=String.format("%d min, %d sec", TimeUnit.MILLISECONDS.toMinutes(timeestimated), TimeUnit.MILLISECONDS.toSeconds(timeestimated));
            String TimeRemaining=String.format("%d min, %d sec", TimeUnit.MILLISECONDS.toMinutes(timeremaining), TimeUnit.MILLISECONDS.toSeconds(timeremaining));
            
            
            System.out.println("Page " + CurrentPage +" completed");
            System.out.println("Current Runtime = " + RunTime);
            System.out.println("Average Runtime = " + AverageTime);
            System.out.println("Estimated time = " + TimeEstimated);
            System.out.println("Estimated time remaining  = " +TimeRemaining);

我的输出如下所示：

Page 9 completed
Current Runtime = 0 min, -3 sec
Average Runtime = 0 min, 0 sec
Estimated time = 0 min, -3 sec
Estimated time remaining  = 0 min, 0 sec
Page 10 completed
Current Runtime = 0 min, -3 sec
Average Runtime = 0 min, 0 sec
Estimated time = 0 min, -3 sec
Estimated time remaining  = 0 min, 0 sec
Page 11 completed
Current Runtime = 0 min, -4 sec
Average Runtime = 0 min, 0 sec
Estimated time = 0 min, -3 sec
Estimated time remaining  = 0 min, 0 sec

所以我显然做错了什么，但不能完全弄清楚它是什么。当我运行 10 个循环时，当前运行时间加起来为 20 秒，而构建/运行时间为 27 秒......所以我很茫然。

标签： javatimetime-estimation