一、第一种生成随机图片验证码
public class VerifyCodeUtil {//生成随机数据的数据源 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();}/*** 生成随机验证码文件,并返回验证码值* @param w 宽* @param h 高* @param outputFile 文件* @param verifySize 验证码的长度* @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 输出流* @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("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("F:/verifies");int w = 200, h = 80;for(int i = 0; i < 5; i++){String verifyCode = generateVerifyCode(4);File file = new File(dir, verifyCode + ".jpg");outputImage(w, h, file, verifyCode);}}}
使用方法（参考）
@ApiOperation("返回验证码图片")@RequestMapping(value = "/web/getAuthCode",method = RequestMethod.GET,produces = MediaType.IMAGE_JPEG_VALUE)@ApiImplicitParam(name = "keyCode",value = "当前时间戳",required = true,paramType ="query",dataType = "String")public void getAuthCode(HttpServletResponse response,String keyCode){//生成的验证码key值 DECODE_CONSTANT 自定义的常量String key = DECODE_CONSTANT+keyCode;ServletOutputStream outputStream = null;try {outputStream = response.getOutputStream();String code = VerifyCodeUtil.outputVerifyImage(120, 40, outputStream,4);if (!StringUtils.hasText(code)){//为空处理log.error("注册模块：生成验证码错误");}//设置60秒过期 设置到redis中jedis.setex(key,60L,code);} catch (IOException e) {e.printStackTrace();}finally {if (!ObjectUtils.isEmpty(outputStream)){try {outputStream.close();} catch (IOException e) {e.printStackTrace();}}jedis.close();}}
二、第二种生成图片验证码的方法
Happy Captcha是一款易于使用的Java验证码软件包，旨在花最短的时间，最少的代码量，实现Web站点的验证码功能，Happy Captcha完全遵循Apache 2.0开源许可协议，作者ramostear。
验证码效果图
可以通过设置.style(CaptchaStyle.IMG)来设置展示为图片或者设置.style(CaptchaStyle.ANIM)展示为动画。
使用步骤
1）maven工程仅需引入相关依赖即可
<dependency><groupId>com.ramostear</groupId><artifactId>Happy-Captcha</artifactId><version>1.0.1</version></dependency>
2）使用
@GetMapping("/captcha")@ApiOperation(value = "登录模块生成验证码接口")public void happyCaptcha(HttpServletRequest request, HttpServletResponse response){//生成验证码 只需要添加一行代码即可生成验证码图片，request和response是必须提供的参数。HappyCaptcha.require(request,response).type(CaptchaType.NUMBER).build().finish();}
3）校验
@PostMapping("/verify")public String verify(String code,HttpServletRequest request){//Verification Captchaboolean flag = HappyCaptcha.verification(request,code,true);if(flag){// 校验通过}}
4）清理
当验证码被使用后，可以通过HappyCaptcha类种的remove()方法将Session中存放的验证码清理掉，避免出现一次验证码多次使用的情况。
@GetMapping("/remove/captcha")public void removeCaptcha(HttpServletRequest request){HappyCaptcha.remove(request); }
验证码类型
通过.type(CaptchaType.ARITHMETIC)改变验证码类型。
