— Scott McNealy, Sun Microsystems Chairman, President and ceo

Graphics2D g2d = (Graphics2D) g;
GradientPaint gradient = new GradientPaint(70,70,Color.blue, 150,150, Color.orange);

g2d.setPaint(gradient);
g2d.fi llOval(70,70,100,100);
}
Because life’s too short to paint the 
circle a solid color when there’s a 
gradient blend waiting for you.
public void paintComponent(Graphics g) {
Graphics2D g2d = (Graphics2D) g;

int red = (int) (Math.random() * 255);
int green = (int) (Math.random() * 255);
int blue = (int) (Math.random() * 255);
Color startColor = new Color(red, green, blue);
red = (int) (Math.random() * 255);
green = (int) (Math.random() * 255);
blue = (int) (Math.random() * 255);
Color endColor = new Color(red, green, blue);
GradientPaint gradient = new GradientPaint(70,70,startColor, 150,150, endColor);
g2d.setPaint(gradient);
g2d.fi llOval(70,70,100,100);
}
it’s really a Graphics2D object 
masquerading as a mere Graphics 
object.
cast it so we can call something that 
Graphics2D has but Graphics doesn’t
this sets the virtual paint brush to a 
gradient instead of a solid color
starting pointstarting color ending point ending color
the fillOval() method really means “fill 
the oval with whatever is loaded on your 
paintbrush (i.e. the gradient)”
this is just like the one above, 
except it makes random colors for 
the start and stop colors of the 
gradient. Try it! 

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368
 
chapter 12
events 
and graphics
ß
To make a GUI, start with a window, usually a JFrame 
JFrame frame = new JFrame();
ß
You can add widgets (buttons, text fields, etc.) to the 
JFrame using: