Store object in memory or de-reference it for performance

Question

I have a GUI that contains a Table Object (for displaying columns of data) and a Table Model. The Table Object contains the Table Model.

Is it better to store the Table Model as a object in the User interface or de-reference it as needed? Is there any performance gain keeping it separate? If there is, is it a good design to implement this?

For example:

public GUI {
    private Table table;
    private TableModel model;

    public UI() {
        this.table = new Table();
        this.model = table.getModel();
        }
        public void actionPerformed() {
           // Performance improvement 
           // without having to de-reference it from table
           model.setRowLimit();
        }
    // OR
    public void actionPerformed() {
        // Slower but is it better OO Design
        table.getModel().setRowLimit();
    }
}

The GUI has 10 public methods exposed where the model could be updated or changed.

Answer 1

There will be no difference in performance whatsoever between the two approaches.

I would suggest you don't break the responsibility principle and leave the handling of the tablemodel to the Table class.

One remark though: if there are additional computations done in getTableModel() aside from a plain setter, you will bypass these if your create the local variable. This may or may not be something you desire.