AntiAliasing, stroke width and dashed strokes

class DrawingPanel extends JPanel{

        //global variables for this class
        float[] dash1 = { 10f, 10f}; //Even # parameters are 10pixels dash, 10 pixels space
        //1 parameter: 10pixels line, 10 pixels space.
        //3 parameters: the lines follow this pattern, then the spaces follow this pattern too
        //(float width, int cap, int join, float miterlimit, float[] dash, float dash_phase)
        BasicStroke bs1 = new BasicStroke(3, BasicStroke.CAP_BUTT, BasicStroke.JOIN_ROUND, 1.0f, dash1, 0);

            this.setBackground(new Color(0,0,0,20));
            this.setPreferredSize(new Dimension(panW, panH));  //How to specify the size of a JPanel (see notes)

        public void paintComponent(Graphics g) {
            //paint the background

            //get Graphics2D object for more advanced graphics
            Graphics2D g2 = (Graphics2D) g;

            //turn on antialiasing
            g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);

            //make solid lines 3 pixels wide
            g2.setStroke(new BasicStroke(3));

            g2.drawLine(20, 40, 250, 40);
            g2.drawLine(20, 80, 250, 80);