生成纯数字的验证码

来源：互联网发布：时时彩组六杀号软件编辑：程序博客网时间：2024/06/08 11:43
public class RandomCode {    private int width = 84;    private int height = 28;    public void getCode(HttpServletRequest request,HttpServletResponse response) throws IOException{        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);        Graphics2D g = image.createGraphics();                //创建一个随机数生成器类        Random random = new Random();        g.setColor(Color.WHITE);        g.fillRect(0, 0, width, height);                //创建字体，字体的大小应该根据图片的高度来定        Font font = new Font("雅黑", Font.ITALIC, 30);        //设置字体        g.setFont(font);        //画边框        g.setColor(Color.BLACK);        g.drawRect(0, 0, width, height);        //随机产生160条干扰线，使图像中的认证码不易被其他程序探测到        g.setColor(Color.GRAY);        for (int i = 0; i < 10; i++) {            int x = random.nextInt(width);            int y = random.nextInt(height);            int xl = random.nextInt(12);            int yl = random.nextInt(12);            g.drawLine(x, y, x+xl, y+yl);        }        //randomCode用于保存随机产生的验证码，以便用户登录后进行验证        StringBuffer randomCode=new StringBuffer();        int red=0,green=0,blue=0;        //随机产生4位数字的验证码        for (int i = 0; i < 5; i++) {            //得到产生的随机验证码数字            String strRand = String.valueOf(random.nextInt(10));            //产生随机的颜色分量来构造颜色值，这样输出的每位数字的颜色值都将不同            red=random.nextInt(200);            green=random.nextInt(200);            blue=random.nextInt(200);                        //产生随机高度13至height之间            float imght = 0;            while(imght<=12){                imght = Float.parseFloat(String.valueOf(random.nextInt(height)));            }            //用随机产生的颜色将验证码绘制到图像中            g.setColor(new Color(red, green, blue));            g.drawString(strRand, 13*i+6, height);            //将产生的四个随机数组合在一起            randomCode.append(strRand);        }        //将四位数字的验证码保存到Session中        HttpSession session = request.getSession();        session.setAttribute("randomCode", randomCode.toString());        //禁止图像缓存        response.setHeader("Pragma", "no-cache");        response.setHeader("Cache-Control", "no-cache");        response.setDateHeader("Expires", 0);        response.setContentType("image/jpeg");        //将图像输出到Servlet输出流中        ServletOutputStream stream = response.getOutputStream();        ImageIO.write(image, "jpeg", stream);        stream.close();    }}
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