CareerCup

public class DayHalf {
	
	private String val;
	
	public static DayHalf AM = new DayHalf("AM");
	public static DayHalf PM = new DayHalf("PM");

	public DayHalf(String val) {
		super();
		this.val = val;
	}

	public static void main(String[] args) {
		DayHalf dh1 = DayHalf.AM;
		DayHalf dh2 = DayHalf.PM;
	}
}

public class DayHalf {
	
	private String val;
	
	public static DayHalf AM = new DayHalf("AM");
	public static DayHalf PM = new DayHalf("PM");

	public DayHalf(String val) {
		super();
		this.val = val;
	}

	public static void main(String[] args) {
		DayHalf dh1 = DayHalf.AM;
		DayHalf dh2 = DayHalf.PM;
	}
}

package facebook;

public interface DayHalf {
	public static String AM = "AM";
	public static String PM = "PM";
}

Test case:

package facebook;

import static org.junit.Assert.*;

import org.junit.Test;

public class DayHalfTest {

	@Test
	public void test() {
		assertEquals("AM",DayHalf.AM);
		assertEquals("PM",DayHalf.PM);
	}

}