java 生成透明背景图片

        //开始绘图

         graphics2d.setBackground(Color.WHITE);

         graphics2d.clearRect(0, 0, width, height);

        graphics2d.setPaint(new Color(backgroundcolorR, backgroundcolorG, backgroundcolorB,backgroundcolorA));      //设置背景颜色

        graphics2d.fillRect(0, 0, width, height);  //填充颜色

        //设置透明  start

        bufferedImage = graphics2d.getDeviceConfiguration().createCompatibleImage(width, height, Transparency.TRANSLUCENT);

        graphics2d=bufferedImage.createGraphics();

        //设置透明  end