java计算HHmm格式的时间差

以下是Java中计算HH:mm格式时间差的代码示例：

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class TimeDiff {
    
    public static void main(String[] args) {
        
        String time1 = "08:30";
        String time2 = "12:45";
        
        SimpleDateFormat format = new SimpleDateFormat("HH:mm");
        try {
            Date date1 = format.parse(time1);
            Date date2 = format.parse(time2);
            
            long diff = date2.getTime() - date1.getTime();
            long minutes = diff / (60 * 1000) % 60;
            long hours = diff / (60 * 60 * 1000);
            
            System.out.println("Time difference: " + hours + " hours " + minutes + " minutes");
            
        } catch (ParseException e) {
            e.printStackTrace();
        }
        
    }
    
}

输出结果：

Time difference: 4 hours 15 minutes

代码中，首先定义了两个时间字符串time1和time2，表示两个时间点。然后通过SimpleDateFormat类将时间字符串转换成Date对象。接着计算两个时间点的时间差，单位为毫秒，然后将时间差转换成小时和分钟。最后将计算结果输出即可