EqualityPoint.java

public class EqualityPoint {
    public double x;
    public double y;
    public String pointName;
    public String surfaceName;
    public EqualityPoint(int x,int y,String pointName,String surfaceName){
        this.x=x;
        this.y=y;
        this.pointName=pointName;
        this.surfaceName=surfaceName;
    }
    public boolean equals(Object anObject){
        EqualityPoint aPoint=(EqualityPoint) anObject;
        return x==aPoint.x && y==aPoint.y && pointName.equals(aPoint.pointName);
    }
    public int hashCode(){
        return Double.valueOf(x).hashCode()
                *Double.valueOf(y).hashCode()*pointName.hashCode();
    }
    public static void main(String[] args) {
        EqualityPoint p=new EqualityPoint(3, 4,"A","S1");
        EqualityPoint a=new EqualityPoint(3, 4,"B","S1");
        EqualityPoint b=new EqualityPoint(3, 4,"A","S2");
        EqualityPoint c=new EqualityPoint(3, 5,"A","S2");
        System.out.println("p.equals(a) : "+ (p.equals(a))) ;
        System.out.println("p.equals(b) : "+ (p.equals(b))) ;
        System.out.println("p.equals(c) : "+ (p.equals(c))) ;
    }
   
}