package gradient;
 
import java.awt.Color;
import java.awt.GradientPaint;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import javax.swing.JPanel;
 
/**
 *
 * @author pratama
 */
public class GradientPaintDemo extends JPanel {
 
    public void init() {
        setBackground(Color.WHITE);
    }
 
    @Override
    public void paint(Graphics g) {
        Graphics2D g2 = (Graphics2D) g;
        g2.setPaint(new GradientPaint(20, 100, Color.BLUE, 20, 200, Color.BLACK, false));
        Rectangle r = new Rectangle(5, 5, 200, 200);
        g2.fill(r);
    }
}
 
//buat class main di bawah ini
 
package gradient;
 
import java.awt.ComponentOrientation;
import java.awt.Frame;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JFrame;
import javax.swing.JPanel;
 
 
public class Main extends JPanel{
 
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        // TODO code application logic here
        JFrame frame = new JFrame("Gradient Demo");
        frame.addWindowListener(new WindowAdapter() {
 
            @Override
          public void windowClosing(WindowEvent e){
              System.exit(0);
          }
        });
        GradientPaintDemo demo = new GradientPaintDemo();
        frame.getContentPane().add(demo);
        demo.init();
        frame.pack();
        frame.setSize(250, 250);
        frame.setVisible(true);
    }
}