Do the drawing (called automagically by window system when needed)
g.setColor(Color.white);
Dimension d = getSize();
g.fill3DRect(0, 0, d.width-1, d.height-1, true);
g.setFont(f);
g.setColor(Color.red);
g.drawString("Welcome", 100, 150);
g.drawString("to", 240, 275);
g.drawString("Java", 160, 400);