【精品】好用的验证码工具类VerifyCodeUtils

喜欢ヅ旅行 2022-12-15 12:51 151阅读 0赞

相关博客：

*  [基于Servlet的验证码技术][Servlet]
 *  [基于Java11的Base64工具类][Java11_Base64]

# 验证码工具类 #

import javax.imageio.ImageIO;
    import java.awt.Color;
    import java.awt.Font;
    import java.awt.Graphics;
    import java.awt.Graphics2D;
    import java.awt.RenderingHints;
    import java.awt.geom.AffineTransform;
    import java.awt.image.BufferedImage;
    import java.io.ByteArrayOutputStream;
    import java.io.File;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.OutputStream;
    import java.util.Arrays;
    import java.util.Random;
    
    public class VerifyCodeUtil { 
        //使用到Algerian字体，系统里没有的话需要安装字体，字体只显示大写，去掉了1,0,i,o几个容易混淆的字符
        public static final String VERIFY_CODES = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ";
        private static Random random = new Random();
    
        /** * 使用系统默认字符源生成验证码 * * @param verifySize 验证码长度 * @return */
        public static String generateVerifyCode(int verifySize) { 
            return generateVerifyCode(verifySize, VERIFY_CODES);
        }
    
        /** * 使用指定源生成验证码 * * @param verifySize 验证码长度 * @param sources 验证码字符源 * @return */
        public static String generateVerifyCode(int verifySize, String sources) { 
            if (sources == null || sources.length() == 0) { 
                sources = VERIFY_CODES;
            }
            int codesLen = sources.length();
            Random rand = new Random(System.currentTimeMillis());
            StringBuilder verifyCode = new StringBuilder(verifySize);
            for (int i = 0; i < verifySize; i++) { 
                verifyCode.append(sources.charAt(rand.nextInt(codesLen - 1)));
            }
            return verifyCode.toString();
        }
    
        /** * 生成指定数据的验证码并以Base64编码一字符串形式返回，用于前后分离 * @param w * @param h * @param code * @return * @throws IOException */
        public static String outputImage(int w, int h, String code) throws IOException { 
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
    
            VerifyCodeUtil.outputImage(100, 39, baos, code);
            final String BASE64_IMAGE = "data:image/jpeg;base64,%s";
            String base64Img = String.format(BASE64_IMAGE, Base64Util.encode(baos.toByteArray()));
            return base64Img;
        }
    
    
        /** * 生成指定验证码图像文件 * * @param w * @param h * @param outputFile * @param code * @throws IOException */
        public static void outputImage(int w, int h, File outputFile, String code) throws IOException { 
            if (outputFile == null) { 
                return;
            }
            File dir = outputFile.getParentFile();
            if (!dir.exists()) { 
                dir.mkdirs();
            }
            try { 
                outputFile.createNewFile();
                FileOutputStream fos = new FileOutputStream(outputFile);
                outputImage(w, h, fos, code);
                fos.close();
            } catch (IOException e) { 
                throw e;
            }
        }
    
        /** * 输出指定验证码图片流 * * @param w * @param h * @param os * @param code * @throws IOException */
        public static void outputImage(int w, int h, OutputStream os, String code) throws IOException { 
            int verifySize = code.length();
            BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
            Random rand = new Random();
            Graphics2D g2 = image.createGraphics();
            g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
            Color[] colors = new Color[5];
            Color[] colorSpaces = new Color[]{ Color.WHITE, Color.CYAN,
                    Color.GRAY, Color.LIGHT_GRAY, Color.MAGENTA, Color.ORANGE,
                    Color.PINK, Color.YELLOW};
            float[] fractions = new float[colors.length];
            for (int i = 0; i < colors.length; i++) { 
                colors[i] = colorSpaces[rand.nextInt(colorSpaces.length)];
                fractions[i] = rand.nextFloat();
            }
            Arrays.sort(fractions);
    
            g2.setColor(Color.GRAY);// 设置边框色
            g2.fillRect(0, 0, w, h);
    
            Color c = getRandColor(200, 250);
            g2.setColor(c);// 设置背景色
            g2.fillRect(0, 2, w, h - 4);
    
            //绘制干扰线
            Random random = new Random();
            g2.setColor(getRandColor(160, 200));// 设置线条的颜色
            for (int i = 0; i < 20; i++) { 
                int x = random.nextInt(w - 1);
                int y = random.nextInt(h - 1);
                int xl = random.nextInt(6) + 1;
                int yl = random.nextInt(12) + 1;
                g2.drawLine(x, y, x + xl + 40, y + yl + 20);
            }
    
            // 添加噪点
            float yawpRate = 0.05f;// 噪声率
            int area = (int) (yawpRate * w * h);
            for (int i = 0; i < area; i++) { 
                int x = random.nextInt(w);
                int y = random.nextInt(h);
                int rgb = getRandomIntColor();
                image.setRGB(x, y, rgb);
            }
    
            shear(g2, w, h, c);// 使图片扭曲
    
            g2.setColor(getRandColor(100, 160));
            int fontSize = h - 6;
            Font font = new Font("Algerian", Font.ITALIC, fontSize);
            g2.setFont(font);
            char[] chars = code.toCharArray();
            for (int i = 0; i < verifySize; i++) { 
                AffineTransform affine = new AffineTransform();
                affine.setToRotation(Math.PI / 4 * rand.nextDouble() * (rand.nextBoolean() ? 1 : -1), (w / verifySize) * i + fontSize / 2, h / 2);
                g2.setTransform(affine);
                g2.drawChars(chars, i, 1, ((w - 10) / verifySize) * i + 5, h / 2 + fontSize / 2 - 10);
            }
    
            g2.dispose();
            ImageIO.write(image, "jpg", os);
        }
    
    
        private static Color getRandColor(int fc, int bc) { 
            if (fc > 255) { 
                fc = 255;
            }
            if (bc > 255) { 
                bc = 255;
            }
            int r = fc + random.nextInt(bc - fc);
            int g = fc + random.nextInt(bc - fc);
            int b = fc + random.nextInt(bc - fc);
            return new Color(r, g, b);
        }
    
        private static int getRandomIntColor() { 
            int[] rgb = getRandomRgb();
            int color = 0;
            for (int c : rgb) { 
                color = color << 8;
                color = color | c;
            }
            return color;
        }
    
        private static int[] getRandomRgb() { 
            int[] rgb = new int[3];
            for (int i = 0; i < 3; i++) { 
                rgb[i] = random.nextInt(255);
            }
            return rgb;
        }
    
        private static void shear(Graphics g, int w1, int h1, Color color) { 
            shearX(g, w1, h1, color);
            shearY(g, w1, h1, color);
        }
    
        private static void shearX(Graphics g, int w1, int h1, Color color) { 
            int period = random.nextInt(2);
    
            boolean borderGap = true;
            int frames = 1;
            int phase = random.nextInt(2);
    
            for (int i = 0; i < h1; i++) { 
                double d = (double) (period >> 1)
                        * Math.sin((double) i / (double) period
                        + (6.2831853071795862D * (double) phase)
                        / (double) frames);
                g.copyArea(0, i, w1, 1, (int) d, 0);
                if (borderGap) { 
                    g.setColor(color);
                    g.drawLine((int) d, i, 0, i);
                    g.drawLine((int) d + w1, i, w1, i);
                }
            }
        }
    
        private static void shearY(Graphics g, int w1, int h1, Color color) { 
            int period = random.nextInt(40) + 10; // 50;
            boolean borderGap = true;
            int frames = 20;
            int phase = 7;
            for (int i = 0; i < w1; i++) { 
                double d = (double) (period >> 1)
                        * Math.sin((double) i / (double) period
                        + (6.2831853071795862D * (double) phase)
                        / (double) frames);
                g.copyArea(i, 0, 1, h1, 0, (int) d);
                if (borderGap) { 
                    g.setColor(color);
                    g.drawLine(i, (int) d, i, 0);
                    g.drawLine(i, (int) d + h1, i, h1);
                }
            }
        }
    
        public static void main(String[] args) throws IOException { 
            File dir = new File("D:/upload/verifyCode");
            int w = 200, h = 80;
            for (int i = 0; i < 50; i++) { 
                String verifyCode = generateVerifyCode(4);
                File file = new File(dir, verifyCode + ".jpg");
                outputImage(w, h, file, verifyCode);
            }
        }
    }

# 使用 #

## 示例一 ##

*  后台代码

@RequestMapping("/verifyCode")
    public void getVerifyCode(HttpSession session, HttpServletResponse response) throws IOException { 
        //生成验证码
        String verifyCode = VerifyCodeUtils.generateVerifyCode(4);
        //验证码放入session
        session.setAttribute("verifyCode", verifyCode);
        //验证码存入图片
        response.setContentType("image/png");
        ServletOutputStream outputStream = response.getOutputStream();
        VerifyCodeUtils.outputImage(105, 45, outputStream, verifyCode);
    }

*  页面代码：**实现页面打开显示验证码，单击刷新验证码功能**

## 示例二：前后分离（★★★★★） ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpYW5naGVjYWk1MjE3MTMxNA_size_16_color_FFFFFF_t_70]

@RequestMapping("/getVerifyCode")
        public Result getVerifyCode(HttpSession session, HttpServletResponse response) throws IOException { 
            String key = UUID.randomUUID().toString();
    
            //生成验证码，5位
            String code = VerifyCodeUtil.generateVerifyCode(5);
            //生成验证码对应的图片
            String base64Img = VerifyCodeUtil.outputImage(100, 40, code);
    
            //将生成的数据保存在Redis中
            redisUtil.hset(GlobalConstant.VERIFYCODE_KEY, key, code);
    
            return ResultUtil.success(200, Map.of("key", key, "code", code, "img", base64Img));
        }

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpYW5naGVjYWk1MjE3MTMxNA_size_16_color_FFFFFF_t_70 1]

[Servlet]: https://blog.csdn.net/lianghecai52171314/article/details/103011060?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522160285328619724836715374%2522%252C%2522scm%2522%253A%252220140713.130102334.pc%255Fblog.%2522%257D&request_id=160285328619724836715374&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2~blog~first_rank_v1~rank_blog_v1-1-103011060.pc_v1_rank_blog_v1&utm_term=%E9%AA%8C%E8%AF%81%E7%A0%81&spm=1018.2118.3001.4187
[Java11_Base64]: https://blog.csdn.net/lianghecai52171314/article/details/115405571?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522162142780616780366545442%2522%252C%2522scm%2522%253A%252220140713.130102334.pc%255Fblog.%2522%257D&request_id=162142780616780366545442&biz_id=0&utm_medium=distribute.pc_search_result.none-task-blog-2~blog~first_rank_v2~rank_v29-1-115405571.nonecase&utm_term=base64&spm=1018.2226.3001.4450
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpYW5naGVjYWk1MjE3MTMxNA_size_16_color_FFFFFF_t_70]: /images/20221123/acbbd6901f7849a1b82e89bdb97fde68.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2xpYW5naGVjYWk1MjE3MTMxNA_size_16_color_FFFFFF_t_70 1]: /images/20221123/733050ff5a6248759025edc4cac8b2a0.png