java - 无法比较时间范围

Question

我有两个 String 变量:

• time22 将存储 Linux 命令生成的时间
• timeInTheList 将存储来 self 的 ArrayList
的时间

time22 将获取最新时间，而 timeInTheList 将存储之前的一些时间。

我想比较这两次是否超过 30 分钟，但我无法实现。

我发现打印出一些关于日期、时间和年份的奇怪数据，我只需要时间，不需要任何日期或年份。

代码:

 for(int x = 1;x<list1.size();x+=3)
   {
    try{
         System.out.println("The time grab by linux command :"+time22);
         String timeInTheList = list1.get(x);
         System.out.println("The time in the balcklist.txt :" +timeInTheList);
         SimpleDateFormat dateFormat1 = new SimpleDateFormat("HH:MM:SS"); 
         Date Ftime1 = dateFormat1.parse(timeInTheList);
         Date Stime2 = dateFormat1.parse(time22);
         System.out.println("The Ftime1 value is :" +Ftime1);
         System.out.println("The Stime2 value is :" +Stime2);
         long diff1 = Stime2.getTime() - Ftime1.getTime();
         System.out.println(Stime2.getTime());
         System.out.println(Ftime1.getTime());
         System.out.println("Difference between two time is :"+diff1);
         if(diff1 > 1800)
          {
            System.out.println("it is more than  30 minute in the list");
            String DeletedRule = list1.get(x+1).toString();
            FinalDeletion(DeletedRule);
          }
         else
          {
            System.out.println("Keep in the list first,still not reach 30 minute");
          }
        }
     catch(ParseException e)
       {
         e.printStackTrace();
       }
   }

这是我程序的输出:

Time from linux command(In TimeIsNow Method) :22:02:50
The time grab by linux command :22:02:50
The time in the balcklist.txt :21:19:46
The Ftime1 value is :Thu Jul 01 21:00:00 MYT 1971
The Stime2 value is :Sun Feb 01 22:00:00 MYT 1970
2730600050
47223000046
Difference between two time is :-44492399996
Keep in the list first,still not reach 30 minute

Answer 1

如果您使用的是 Java 8，则可以使用新日期/时间 API。 请尝试以下代码:

// Required imports
import java.time.LocalTime;
import java.time.Duration;

// Taken hard-coded values for testing purpose
String time22 = "22:02:50", timeInTheList = "21:19:46";

LocalTime Stime2 = LocalTime.parse(time22);
LocalTime Ftime1 = LocalTime.parse(timeInTheList);

System.out.println("Stime2: " + Stime2);
System.out.println("Ftime1: " + Ftime1);

Duration duration = Duration.between(Ftime1, Stime2);
long diff1 = duration.getSeconds();
System.out.println("duration: " + diff1);

if(diff1 > 1800){
  System.out.println("it is more than 30 minute in the list");
  /**
   * Your remaining code goes here.
   */
}else{
  System.out.println("Keep in the list first, still not reach 30 minute");
}