【登录验证码】动态与静态验证码实现逻辑

素颜马尾好姑娘i 2022-10-26 03:48 362阅读 0赞

目录

1、需要设计一个静态验证码实体类

随机生成字母数字的工具类

Captcha验证码类

动画gif实体类

验证码前端接口

前言

要实现一个静态的简单地字母数字的验证码登录，同时也实现一个划拉式的验证码动态匹配的实现逻辑；

1、需要设计一个静态验证码实体类

随机生成字母数字的工具类

  1. /**
  2.  *随机工具类 作为一个随机生成字母数字的工具类
  3.  * @version:1.0
  4.  */
  5. public class Randoms
  6. {
  7.     private static final Random RANDOM = new Random();
  8.     //定义验证码字符.去除了O和I等容易混淆的字母
  9.     public static final char ALPHA[]={'A','B','C','D','E','F','G','H','G','K','M','N','P','Q','R','S','T','U','V','W','X','Y','Z'
  10.             ,'a','b','c','d','e','f','g','h','i','j','k','m','n','p','q','r','s','t','u','v','w','x','y','z','2','3','4','5','6','7','8','9'};
  12.     /**
  13.      * 产生两个数之间的随机数
  14.      * @param min 小数
  15.      * @param max 比min大的数
  16.      * @return int 随机数字
  17.      */
  18.     public static int num(int min, int max)
  19.     {
  20.         return min + RANDOM.nextInt(max - min);
  21.     }
  23.     /**
  24.      * 产生0--num的随机数,不包括num
  25.      * @param num 数字
  26.      * @return int 随机数字
  27.      */
  28.     public static int num(int num)
  29.     {
  30.         return RANDOM.nextInt(num);
  31.     }
  33.     public static char alpha()
  34.     {
  35.         return ALPHA[num(0, ALPHA.length)];
  36.     }
  37. }

Captcha验证码类

  1. /**
  2.  * 验证码抽象类,暂时不支持中文，目前仅仅支持随机的字母数字
  3.  * @version:1.0
  4.  */
  5. @Data
  6. public abstract class Captcha extends Randoms {
  7.    /**
  8.     * 字体
  9.     */
  10.    protected Font font = new Font("Verdana", Font.ITALIC | Font.BOLD, 28);
  11.     // 验证码随机字符长度
  12.    /**
  13.     * 验证码随机字符长度
  14.     */
  15.     protected int len = 5;
  16.    /**
  17.     * 宽度
  18.     */
  19.    protected int width = 150;
  20.     // 验证码显示高度
  21.    /**
  22.     * 高度
  23.     */
  24.     protected int height = 40;
  25.    /**
  26.     * 随机字符串
  27.     */
  28.    private String chars = null;
  30.     /**
  31.      * 生成随机字符数组
  32.      *
  33.      * @return 字符数组
  34.      */
  35.     protected char[] alphas() {
  36.         char[] cs = new char[len];
  37.         for (int i = 0; i < len; i++) {
  38.             cs[i] = alpha();
  39.         }
  40.         chars = new String(cs);
  41.         return cs;
  42.     }
  45.     /**
  46.      * 给定范围获得随机颜色
  47.      *
  48.      * @return Color 随机颜色
  49.      */
  50.     protected Color color(int fc, int bc) {
  51.         if (fc > INT_TWO_FIVE_FIVE) {
  52.             fc = INT_TWO_FIVE_FIVE;
  53.         }
  54.         if (bc > INT_TWO_FIVE_FIVE) {
  55.             bc = INT_TWO_FIVE_FIVE;
  56.         }
  57.         int r = fc + num(bc - fc);
  58.         int g = fc + num(bc - fc);
  59.         int b = fc + num(bc - fc);
  60.         return new Color(r, g, b);
  61.     }
  63.     /**
  64.      * 验证码输出,抽象方法，由子类实现
  65.      *
  66.      * @param os 输出流
  67.      */
  68.     public abstract void out(OutputStream os);
  70.     /**
  71.      * 获取随机字符串
  72.      *
  73.      * @return string
  74.      */
  75.     public String text() {
  76.         return chars;
  77.     }
  78. }
  80. /**
  81.  * int常量
  82.  */
  83. public static final int INT_ZERO = 0;
  84. public static final int INT_ONE = 1;
  85. public static final int INT_TWO = 2;
  86. public static final int INT_THREE = 3;
  87. public static final int INT_FIVE = 5;
  88. public static final int INT_SERVEN = 7;
  89. public static final int INT_TWO_FIVE_FIVE = 255;

动画gif实体类

  1. /**
  2.  * <p>Gif验证码类</p>
  3.  * @version:1.0
  4.  */
  5. public class GifCaptcha extends Captcha
  6. {
  7.     public GifCaptcha()
  8.     {
  9.     }
  11.     public GifCaptcha(int width,int height){
  12.         this.width = width;
  13.         this.height = height;
  14.     }
  16.     public GifCaptcha(int width,int height,int len){
  17.         this(width,height);
  18.         this.len = len;
  19.     }
  21.     public GifCaptcha(int width,int height,int len,Font font)
  22.     {
  23.         this(width,height,len);
  24.         this.font = font;
  25.     }
  27.     @Override
  28.     public void out(OutputStream os)
  29.     {
  30.         try
  31.         {
  32.             // gif编码类，这个利用了洋人写的编码类，所有类都在附件中
  33.             GifEncoder gifEncoder = new GifEncoder();
  34.             //生成字符
  35.             gifEncoder.start(os);
  36.             gifEncoder.setQuality(180);
  37.             gifEncoder.setDelay(100);
  38.             gifEncoder.setRepeat(0);
  39.             BufferedImage frame;
  40.             char[] rands =alphas();
  41.             Color fontcolor[]=new Color[len];
  42.             for(int i=0;i<len;i++)
  43.             {
  44.                 fontcolor[i]=new Color(20 + num(110), 20 + num(110), 20 + num(110));
  45.             }
  46.             for(int i=0;i<len;i++)
  47.             {
  48.                 frame=graphicsImage(fontcolor, rands, i);
  49.                 gifEncoder.addFrame(frame);
  50.                 frame.flush();
  51.             }
  52.             gifEncoder.finish();
  53.         }finally
  54.         {
  55.            try {
  56.             os.close();
  57.          } catch (IOException e) {
  58.             // TODO Auto-generated catch block
  59.             e.printStackTrace();
  60.          }
  61.         }
  63.     }
  65.     /**
  66.      * 画随机码图
  67.      * @param fontcolor 随机字体颜色
  68.      * @param strs 字符数组
  69.      * @param flag 透明度使用
  70.      * @return BufferedImage
  71.      */
  72.     private BufferedImage graphicsImage(Color[] fontcolor,char[] strs,int flag)
  73.     {
  74.         BufferedImage image = new BufferedImage(width, height,BufferedImage.TYPE_INT_RGB);
  75.         //或得图形上下文
  76.         //Graphics2D g2d=image.createGraphics();
  77.         Graphics2D g2d = (Graphics2D)image.getGraphics();
  78.         //利用指定颜色填充背景
  79.         g2d.setColor(Color.WHITE);
  80.         g2d.fillRect(0, 0, width, height);
  81.         AlphaComposite ac3;
  82.         int h  = height - ((height - font.getSize()) >>1) ;
  83.         int w = width/len;
  84.         g2d.setFont(font);
  85.         for(int i=0;i<len;i++)
  86.         {
  87.             ac3 = AlphaComposite.getInstance(AlphaComposite.SRC_OVER, getAlpha(flag, i));
  88.             g2d.setComposite(ac3);
  89.             g2d.setColor(fontcolor[i]);
  90.             g2d.drawOval(num(width), num(height), 5+num(10), 5+num(10));
  91.             g2d.drawString(strs[i]+"", (width-(len-i)*w)+(w-font.getSize())+1, h-4);
  92.         }
  93.         g2d.dispose();
  94.         return image;
  95.     }
  97.     /**
  98.      * 获取透明度,从0到1,自动计算步长
  99.      * @return float 透明度
  100.      */
  101.     private float getAlpha(int i,int j)
  102.     {
  103.         int num = i+j;
  104.         float r = (float)1/len,s = (len+1) * r;
  105.         return num > len ? (num *r - s) : num * r;
  106.     }
  108. }

验证码前端接口

  1. @Autowired
  2.     private ZaptchaProperties captchaProperties;
  3.     @Autowired
  4.     private Producer producer;
  5.     @Autowired
  6.     private RedisUtil redisUtil;
  8.     /**
  9.      * 生成gif验证码
  10.      */
  11.     @RequestMapping("/gif")
  12.     public void indexGif(HttpServletRequest request, HttpServletResponse response) {
  13.         String captchaId = request.getParameter("captchaId");
  14.         if (ToolUtil.isEmpty(captchaId)) {
  15.             throw new ServiceException(ExceptionEnum.REQUEST_NULL);
  16.         }
  18.         Captcha gifCaptcha = new GifCaptcha(captchaProperties.getCaptchaWidth(),
  19.                 captchaProperties.getCaptchaHigh(),
  20.                 captchaProperties.getCaptchaLen());
  21.         response.setDateHeader("Expires", 0);
  22.         // Set standard HTTP/1.1 no-cache headers.
  23.         response.setHeader("Cache-Control", "no-store, no-cache, must-revalidate");
  24.         // Set IE extended HTTP/1.1 no-cache headers (use addHeader).
  25.         response.addHeader("Cache-Control", "post-check=0, pre-check=0");
  26.         // Set standard HTTP/1.0 no-cache header.
  27.         response.setHeader("Pragma", "no-cache");
  28.         // return a jpeg
  29.         response.setContentType("image/gif");
  30.         //输出
  31.         //存入Session
  32.         OutputStream out = null;
  33.         try {
  34.             out = response.getOutputStream();
  35.             gifCaptcha.out(out);
  36.             redisUtil.set(captchaProperties.getCaptchaSessionKey() + captchaId, gifCaptcha.text().toLowerCase(), captchaProperties.getCaptchaSessionExpired());
  37.         } catch (Exception e) {
  38.             e.printStackTrace();
  39.         } finally {
  40.             if (out != null) {
  41.                 try {
  42.                     out.close();
  43.                 } catch (IOException e) {
  44.                     e.printStackTrace();
  45.                 }
  46.             }
  47.         }
  48.     }
  51.     /**
  52.      * 生成普通验证码
  53.      */
  54.     @RequestMapping("pic")
  55.     public void indexPic(HttpServletRequest request, HttpServletResponse response) {
  56.         String captchaId = request.getParameter("captchaId");
  57.         if (ToolUtil.isEmpty(captchaId)) {
  58.             throw new ServiceException(ExceptionEnum.REQUEST_NULL);
  59.         }
  60.         response.setDateHeader("Expires", 0);
  62.         // Set standard HTTP/1.1 no-cache headers.
  63.         response.setHeader("Cache-Control", "no-store, no-cache, must-revalidate");
  65.         // Set IE extended HTTP/1.1 no-cache headers (use addHeader).
  66.         response.addHeader("Cache-Control", "post-check=0, pre-check=0");
  68.         // Set standard HTTP/1.0 no-cache header.
  69.         response.setHeader("Pragma", "no-cache");
  71.         // return a jpeg
  72.         response.setContentType("image/jpeg");
  74.         // create the text for the image
  75.         String capText = producer.createText();
  76.         // create the image with the text
  77.         BufferedImage bi = producer.createImage(capText);
  78.         ServletOutputStream out = null;
  79.         try {
  80.             out = response.getOutputStream();
  81.         } catch (IOException e) {
  82.             e.printStackTrace();
  83.         }
  84.         // write the data out
  85.         try {
  86.             ImageIO.write(bi, "jpg", out);
  87.             redisUtil.set(captchaProperties.getCaptchaSessionKey() + captchaId, capText.toLowerCase(), captchaProperties.getCaptchaSessionExpired());
  88.         } catch (IOException e) {
  89.             e.printStackTrace();
  90.         }
  91.         try {
  92.             try {
  93.                 out.flush();
  94.             } catch (IOException e) {
  95.                 e.printStackTrace();
  96.             }
  97.         } finally {
  98.             try {
  99.                 out.close();
  100.             } catch (IOException e) {
  101.                 e.printStackTrace();
  102.             }
  103.         }
  104.     }
  106. }

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