Count angle made of hour hand and minute hand

ClockAngle.java

package com.company;

/**
 * Created by tandat on 10/14/16.
 */
public class ClockAngle {
    public static void main(String[] args) {
        System.out.println("Angle = " + countAngle(12, 15));
    }
    public static double countAngle(int h, int m){
//        1 phut = kim phut di duoc 6 do//        one minute make
//              = kim gio di duoc 0.5 do//        one minute make
//        1 gio = kim gio di duoc 30 do
        double mAngle = m * 6;
        double hAngle = h * 30 + m * 0.5;
        double angle = Math.abs(hAngle - mAngle);
        angle = angle > 180 ? 360 - angle: angle;
        return angle;
    }

}

ClockAngleTest.groovy

package com.company

import org.junit.Test
import org.junit.runner.JUnitCore
import org.junit.runner.Result
import org.junit.runner.notification.Failure

/**
 * Created by tandat on 10/14/16.
 */
class ClockAngleTest extends GroovyTestCase {
    @Test
    public static void testCountAngle(){
        double angle = ClockAngle.countAngle(0, 0);
        println angle;
        assertEquals(angle, 0.0);

        angle = ClockAngle.countAngle(4, 10);
        println angle;
        assertEquals(angle, 65.0);

        angle = ClockAngle.countAngle(8, 30);
        println angle;
        assertEquals(angle, 75.0);

    }

    public static void main(String[] args) {
        Result result = JUnitCore.runClasses(ClockAngleTest.class);

        for (Failure failure : result.getFailures()) {
            System.out.println(failure.toString());
        }

        System.out.println(result.wasSuccessful());
    }
}