java生成验证码-蒲公英云

java生成验证码

心已赠人 2022-07-13 06:52 297阅读 0赞

前端调用：

后台代码：

private int                    w                = 70;
    private int                    h                = 26;
    /**
     * 生成验证码
     */
    @RequestMapping
    public void captcha(String width, String height, HttpServletResponse response, Model model)
    {
        OutputStream out = null;
        try
        {
            response.setHeader("Pragma", "no-cache");
            response.setHeader("Cache-Control", "no-cache");
            response.setDateHeader("Expires", 0);
            response.setContentType("image/jpeg");
            if (StringUtils.isNumeric(width) && StringUtils.isNumeric(height))
            {
                w = NumberUtils.toInt(width);
                h = NumberUtils.toInt(height);
            }
            BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
            Graphics g = image.getGraphics();
            g.setColor(getRandColor(220, 250));// 生成背景
            g.fillRect(0, 0, w, h);
            for (int i = 0; i < 8; i++) // 加入干扰线条
            {
                g.setColor(getRandColor(40, 150));
                Random random = new Random();
                int x = random.nextInt(w);
                int y = random.nextInt(h);
                int x1 = random.nextInt(w);
                int y1 = random.nextInt(h);
                g.drawLine(x, y, x1, y1);
            }
            String s = createCharacter(g);// 生成字符
            SessionUtils.put(Constants.SESSION_KEY_CAPTCHA, s);
            g.dispose();
            out = response.getOutputStream();
            ImageIO.write(image, "JPEG", out);
            out.close();
        }
        catch (Exception e)
        {
            logger.error("Write Captcha Error", e);
        }
        finally
        {
            IOUtils.closeQuietly(out);
        }
    }
    private Color getRandColor(int fc, int bc)
    {
        int f = fc;
        int b = bc;
        Random random = new Random();
        if (f > 255)
        {
            f = 255;
        }
        if (b > 255)
        {
            b = 255;
        }
        return new Color(f + random.nextInt(b - f), f + random.nextInt(b - f), f + random.nextInt(b - f));
    }
    private String createCharacter(Graphics g)
    {
        char[] codeSeq =
        { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J', 'K', 'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', '2', '3', '4', '5', '6', '7', '8', '9' };
                //字体：宋体, 新宋体, 黑体, 楷体, 隶书
        String[] fontTypes =
        { "\u5b8b\u4f53", "\u65b0\u5b8b\u4f53", "\u9ed1\u4f53", "\u6977\u4f53", "\u96b6\u4e66" };
        Random random = new Random();
        StringBuilder s = new StringBuilder();
        for (int i = 0; i < 4; i++)
        {
            String r = String.valueOf(codeSeq[random.nextInt(codeSeq.length)]);
            g.setColor(new Color(50 + random.nextInt(100), 50 + random.nextInt(100), 50 + random.nextInt(100)));
            g.setFont(new Font(fontTypes[random.nextInt(fontTypes.length)], Font.BOLD, 26));
            g.drawString(r, 15 * i + 5, 19 + random.nextInt(8));
            s.append(r);
        }
        return s.toString();
    }