//DateComparator.java
//example of a class to compare user-defined objects so they can be used in a Collection for sorting

import java.util.*;

//**comparator for specifying how to compare Dates.
//***your class implementing Comparator interface which requires the compare method
public class DateComparator implements Comparator {

    //***must be this signature. Note the two parameters are Objects.
    //***must return 0 if equal, positive if a>b, negative if a<b
    public int compare(Object a, Object b) {
	//***must cast the Object parameters to Dates:
	Date d1 = (Date) a;
	Date d2 = (Date) b;

	if (d1.getYear() > d2.getYear())
	    return 1;
	else if (d1.getYear() < d2.getYear())
	    return -1;
	else if (d1.getMonth() > d2.getMonth())
	    return 1;
	else if (d1.getMonth() < d2.getMonth())
	    return -1;
	else if (d1.getDay() > d2.getDay())
	    return 1;
	else if (d1.getDay() < d2.getDay())
	    return -1;
	else 
	    return 0;    //same dates
    }
}