JAVA中如何image填充透明

 

//getGraphics()).

g2.setComposite(AlphaComposite.getInstance(AlphaComposite.CLEAR));

g2.fillRect(0,0,width, height);

 

//reset composite

g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER));

//draw

g2.setPaint(Color.RED);

g2.fillOval(50,50,100,100);