生成验证码图片的完整Java工具代码

清疚 2023-10-11 22:23 48阅读 0赞

package util;
    
    import javax.imageio.ImageIO;
    import java.awt.*;
    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;
    
    /**
     * 生成验证码工具类
     */
    public class CheckCodeUtil {
        
    
        public static final String VERIFY_CODES = "123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        private static Random random = new Random();
    
    
    
        /**
         * 输出随机验证码图片流,并返回验证码值（一般传入输出流，响应response页面端，Web项目用的较多）
         * w:宽 h:高 verifySize；随机数数量
         * @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;
        }
    
        /**
         * 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) {
        
            // 未设定展示源的字码，赋默认值大写字母+数字
            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 (生成图片形式，用的较少)
         *
         * @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;
        }
    
    
    
        /**
         * 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();
            //文件不存在
            if (!dir.exists()) {
        
                //创建
                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);
    
            // 创建颜色集合，使用java.awt包下的类
            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);
            // 设置边框色
            g2.setColor(Color.GRAY);
            g2.fillRect(0, 0, w, h);
    
            Color c = getRandColor(200, 250);
            // 设置背景色
            g2.setColor(c);
            g2.fillRect(0, 2, w, h - 4);
    
            // 绘制干扰线
            Random random = new Random();
            // 设置线条的颜色
            g2.setColor(getRandColor(160, 200));
            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
            // 噪声率
            float yawpRate = 0.05f;
            int area = (int) (yawpRate * w * h);
            for (int i = 0; i < area; i++) {
        
                int x = random.nextInt(w);
                int y = random.nextInt(h);
                // 获取随机颜色
                int rgb = getRandomIntColor();
                image.setRGB(x, y, rgb);
            }
            // 添加图片扭曲
            shear(g2, w, h, c);
    
            g2.setColor(getRandColor(100, 160));
            int fontSize = h - 4;
            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);
        }
    
        /**
         * 随机颜色
         *
         * @param fc
         * @param bc
         * @return
         */
        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);
                }
    
            }
    
        }
    }