public class Map extends JMapViewer {

    public Map()         {
            new DefaultMapController(this){
                    public void mousePressed(MouseEvent e) {
                            this.setMovementMouseButton(MouseEvent.BUTTON1);
                    }
            };
    }
}

public class JMapViewerDemo {
    public static void main(String[] args) {
           JFrame f = new JFrame();
           f.add(new Map());
           f.setSize(800, 600);
           f.setVisible(true);
           f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}

public void mousePressed(MouseEvent e) {
     super.mousePressed(e);      //Calling the parent-class method
     this.setMovementMouseButton(MouseEvent.BUTTON1);
}