import java.time.LocalTime;
import java.time.temporal.ChronoUnit;
 
 
/**
 *
 * @author bogusz.thierry
 */
public class JavaApplication1 {
 
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        LocalTime h1 = LocalTime.parse("10:45");
        LocalTime h2 = LocalTime.parse("12:50");
 
        long m = h1.until(h2,ChronoUnit.MINUTES);
        long m2 = ChronoUnit.MINUTES.between(h1,h2);
 
        System.out.println(m + ":" + m2); // même résultat !
 
    }
 
}

• https://docs.oracle.com/javase/8/docs/api/java/time/temporal/ChronoUnit.html
• http://www.java2s.com/Tutorials/Java/java.time/LocalTime/index.htm