java web 验证码-字符变形（推荐）

我不是女神ヾ 2021-10-01 07:10 220阅读 0赞

该文章转载自：http://www.cnblogs.com/jianlun/articles/5553452.html

因为在我做的这个系统中发现验证码有点偏上，整体效果看起来不太好，就做了一些修改。

java代码（图片工具类）VerifyCodeUtils：

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.File;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.OutputStream;
    import java.util.Arrays;
    import java.util.Random;
    
    import javax.imageio.ImageIO;
    
    /**
     * 生成验证码
     */
    public class VerifyCodeUtils {
    
        // 使用到'楷体'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 = "23456789abcdefghjkmnprstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ";
        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();
        }
    
        /**
         * 生成随机验证码文件,并返回验证码值
         * 
         * @param w
         * @param h
         * @param outputFile
         * @param verifySize
         * @return
         * @throws IOException
         */
        public static String outputVerifyImage(int w, int h, File outputFile,
                int verifySize) throws IOException {
            String verifyCode = generateVerifyCode(verifySize);
            outputImage(w, h, outputFile, verifyCode);
            return verifyCode;
        }
    
        /**
         * 输出随机验证码图片流,并返回验证码值
         * 
         * @param w
         * @param h
         * @param os
         * @param verifySize
         * @return
         * @throws IOException
         */
        public static String outputVerifyImage(int w, int h, OutputStream os,
                int verifySize) throws IOException {
            String verifyCode = generateVerifyCode(verifySize);
            outputImage(w, h, os, verifyCode);
            return verifyCode;
        }
    
        /**
         * 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 - 4;
            Font font = new Font("楷体", Font.BOLD, 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 - 5);
            }
    
            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("F:/verifies");
            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);
            }
        }
    }

java代码 controller调用：

@Controller
    @RequestMapping("randomCheckCode")
    public class RandomCheckCodeController {
    
        @RequestMapping("generate")
        public void generateNumber(HttpServletRequest request,
                HttpServletResponse response) {
            response.setHeader("Pragma", "No-cache");
            response.setHeader("Cache-Control", "no-cache");
            response.setDateHeader("Expires", 0);
            response.setContentType("image/jpeg");
            // 生成随机字串
            String verifyCode = VerifyCodeUtils.generateVerifyCode(4);
            // 存入会话session
            HttpSession session = request.getSession(true);
            // 删除以前的验证码
            session.removeAttribute("verCode");
            session.setAttribute("verCode", verifyCode.toLowerCase());
            // 生成图片
            int w = 80, h = 30;
            try {
                VerifyCodeUtils.outputImage(w, h, response.getOutputStream(),
                        verifyCode);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

页面代码：

<img src="${ctx }/randomCheckCode/generate?t=1" id="checkCode" align="middle" onclick="reloadPic()" style=" width: 100%; height: 32px;border-radius: 4px;">
    
    <script type="text/javascript">
    function reloadPic() {  
        document.getElementById("checkCode").src = document.getElementById("checkCode").src + "1";
    }  
    </script>

感觉这个验证码效果非常不错。java工具类代码里有main方法可以直接生成图片调用。非常感谢写出这段代码的大神。

转载于:https://www.cnblogs.com/qlong8807/p/6776177.html