Question

Let’s say I have this custom component. It subclasses JMenuItem and all instances use the same Font object, although none share the same instance. For example,

public abstract class JFooMenuItem extends JMenuItem{
    public JFooMenuItem(final String title){
        super(title);
        setFont(new Font("Courier New", Font.BOLD, 12));
    }
}

Now, given that there may be up to 10+ menu items, would it be more efficient to make the Font instance a shared, static member variable, or is this current setup (i.e. the code above) just fine (memory-management-wise)?

Answer 1

I would say use one named instance, not because of the memory, but because if you decide to change the font, you have to edit at 10+ places.

public static final Font MENU_FONT = new Font("Courier New", Font.BOLD, 12);

Edit: Even if you use subclassing, better declare it as public static final because the Font is constant. It is more clear.