Java Graphics2D .setComposite (Composite comp)

public abstract void setComposite(Composite comp)

/*from  ww  w  . ja v a2 s . c  o  m*/
import java.awt.AlphaComposite;
import java.awt.Color;
import java.awt.Composite;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.geom.Rectangle2D;

import javax.swing.JFrame;
import javax.swing.JPanel;

public class Main extends JPanel {
  public void paint(Graphics g) {
    Graphics2D g2 = (Graphics2D)g;
    
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
        RenderingHints.VALUE_ANTIALIAS_ON);

    Rectangle2D r = new Rectangle2D.Double(50, 50, 150, 100);
    g2.setPaint(Color.red);
    g2.fill(r);

    Composite c = AlphaComposite.getInstance(AlphaComposite.SRC_OVER,
       .4f);
    g2.setComposite(c);


    g2.setPaint(Color.blue);
    g2.setFont(new Font("Times New Roman", Font.PLAIN, 72));
    g2.drawString("www.java2s.com", 25, 130);
  }

  public static void main(String[] args) {
    JFrame frame = new JFrame();
    frame.add(new Main());
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setBounds(20, 20, 500, 500);
    frame.setVisible(true);
  }
}