java后台生成背景透明的验证码

private char[] code = { 'A', '1','B', 'C', '2','D','3', 'E','4', 'F', '5','G','6', 'H', '7','I', '8','J',  
            'K',   '9' ,'L', '1','M',  '2','N',  'P', '3', 'Q', '4', 'R', 'S', 'T', 'U', 'V', 'W',  
            'X', 'Y', 'Z'}; 


 @RequestMapping("/codes")  
    public void getCodes(HttpServletResponse response) throws Exception {  
    
        int width = 167;  
        int height = 57;  
        Random random = new Random();  
        //设置response头信息  
        //禁止缓存  
        response.setHeader("Pragma", "No-cache");  
        response.setHeader("Cache-Control", "no-cache");  
        response.setDateHeader("Expires", 0);  
  
        //生成缓冲区image类  
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);  
        //产生image类的Graphics用于绘制操作  
        
        Graphics g = image.getGraphics();  
        
        image=((Graphics2D) g).getDeviceConfiguration().createCompatibleImage(width, height, Transparency.TRANSLUCENT);
        g= image.createGraphics();
        //Graphics类的样式  
        
       // g.setColor(getRandColor(200, 250));  
        g.setFont(new Font("Times New Roman",0,48));  
        //g.fillRect(0, 0, width, height);