Overriding the java equals() method - not working?

Question

I ran into an interesting (and very frustrating) issue with the equals() method today which caused what I thought to be a well tested class to crash and cause a

Answer 1

If you use eclipse just go to the top menu

Source --> Generate equals() and hashCode()

Answer 2

in Android Studio is alt + insert ---> equals and hashCode

Example:

    @Override
public boolean equals(Object o) {
    if (this == o) return true;
    if (o == null || getClass() != o.getClass()) return false;

    Proveedor proveedor = (Proveedor) o;

    return getId() == proveedor.getId();

}

@Override
public int hashCode() {
    return getId();
}