Add item only once in custom ArrayList

Question

I\'ve made my own custom ArrayList like this:

public class Points {
    String hoodName;
    Double points;
    Integer hoodId;
    public Points(String hN, Doub         


        

Answer 1

In this case the Points object use default equals() method which is inconsistent. As you want to use contains method, you should implement equals() method like this way.

public class Points {

    String hoodName;
    Double points;
    Integer hoodId;

    public Points(String hN, Double p, Integer hI) {
        hoodName = hN;
        points = p;
        hoodId = hI;
    }

    public Double getPoints() {
        return points;
    }

    public Integer getHoodId() {
        return hoodId;
    }

    public String getHoodName() {
        return hoodName;
    }


    @Override
    public boolean equals(Object obj) {
        if (!(obj instanceof Points)) {
            return false;
        }
        Points points = (Points) obj;

        return points.getHoodName().equals(getHoodName().trim()) &&
                points.getHoodId() == getHoodId()
                && points.getPoints() == getPoints();


      }

    }

If you ovverride equals() method, you can easily use it in ArrayList. Hope it will work in your case.