springboot实现验证码功能

实现验证码功能

1. 先在utils包下创建一个ValidateImageCodeUtils.class

   package com.wfszmg.demo.utils;
   
   import javax.imageio.ImageIO;
   import java.awt.*;
   import java.awt.image.BufferedImage;
   import java.io.FileOutputStream;
   import java.io.IOException;
   import java.util.Arrays;
   import java.util.Random;
   
   /**
    * @author 无法手执玫瑰
    * 2020/07/0021 13:04
    */
   public class ValidateImageCodeUtils {
       /**
        * 验证码难度级别 Simple-数字 Medium-数字和小写字母 Hard-数字和大小写字母
        */
       public enum SecurityCodeLevel {
           Simple, Medium, Hard
       }
   
       ;
   
       /**
        * 产生默认验证码，4位中等难度
        *
        * @return
        */
       public static String getSecurityCode() {
           return getSecurityCode(4, SecurityCodeLevel.Medium, false);
       }
   
       /**
        * 产生长度和难度任意的验证码
        *
        * @param length
        * @param level
        * @param isCanRepeat
        * @return
        */
       public static String getSecurityCode(int length, SecurityCodeLevel level, boolean isCanRepeat) {
           // 随机抽取len个字符
           int len = length;
           // 字符集合（--除去易混淆的数字0,1,字母l,o,O）
           char[] codes = {
                   '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
                   'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
                   'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'
           };
           // 根据不同难度截取字符串
           if (level == SecurityCodeLevel.Simple) {
               codes = Arrays.copyOfRange(codes, 0, 10);
           } else if (level == SecurityCodeLevel.Medium) {
               codes = Arrays.copyOfRange(codes, 0, 36);
           }
           // 字符集和长度
           int n = codes.length;
           // 抛出运行时异常
           if (len > n && isCanRepeat == false) {
               throw new RuntimeException(String.format("调用SecurityCode.getSecurityCode(%1$s,%2$s,%3$s)出现异常，" + "当isCanRepeat为%3$s时，传入参数%1$s不能大于%4$s", len, level, isCanRepeat, n));
           }
           // 存放抽取出来的字符
           char[] result = new char[len];
           // 判断能否出现重复字符
           if (isCanRepeat) {
               for (int i = 0; i < result.length; i++) {
                   // 索引0 and n-1
                   int r = (int) (Math.random() * n);
                   // 将result中的第i个元素设置为code[r]存放的数值
                   result[i] = codes[r];
               }
           } else {
               for (int i = 0; i < result.length; i++) {
                   // 索引0 and n-1
                   int r = (int) (Math.random() * n);
                   // 将result中的第i个元素设置为code[r]存放的数值
                   result[i] = codes[r];
                   // 必须确保不会再次抽取到那个字符，这里用数组中最后一个字符改写code[r],并将n-1
                   codes[r] = codes[n - 1];
                   n--;
               }
           }
           return String.valueOf(result);
       }
   
       /**
        * 生成验证码图片
        *
        * @param securityCode
        * @return
        */
       public static BufferedImage createImage(String securityCode) {
   
           int codeLength = securityCode.length();//验证码长度
   
           int fontSize = 18;//字体大小
   
           int fontWidth = fontSize + 1;
   
           //图片宽高
   
           int width = codeLength * fontWidth + 6;
           int height = fontSize * 2 + 1;
           //图片
   
           BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
   
           Graphics2D g = image.createGraphics();
   
           g.setColor(Color.WHITE);//设置背景色
   
           g.fillRect(0, 0, width, height);//填充背景
   
           g.setColor(Color.LIGHT_GRAY);//设置边框颜色
   
           g.setFont(new Font("Arial", Font.BOLD, height - 2));//边框字体样式
   
           g.drawRect(0, 0, width - 1, height - 1);//绘制边框
   
           //绘制噪点
   
           Random rand = new Random();
   
           g.setColor(Color.LIGHT_GRAY);
   
           for (int i = 0; i < codeLength * 6; i++) {
   
               int x = rand.nextInt(width);
   
               int y = rand.nextInt(height);
   
               g.drawRect(x, y, 1, 1);//绘制1*1大小的矩形
   
           }
   
           //绘制验证码
   
           int codeY = height - 10;
   
           g.setColor(new Color(19, 148, 246));
   
           g.setFont(new Font("Georgia", Font.BOLD, fontSize));
           for (int i = 0; i < codeLength; i++) {
               double deg = new Random().nextDouble() * 20;
               g.rotate(Math.toRadians(deg), i * 16 + 13, codeY - 7.5);
               g.drawString(String.valueOf(securityCode.charAt(i)), i * 16 + 5, codeY);
               g.rotate(Math.toRadians(-deg), i * 16 + 13, codeY - 7.5);
           }
   
           g.dispose();//关闭资源
           return image;
       }
   
       public static void main(String[] args) throws IOException {
           String securityCode = ValidateImageCodeUtils.getSecurityCode();
           System.out.println(securityCode);
   
           BufferedImage image = ValidateImageCodeUtils.createImage(securityCode);
           ImageIO.write(image, "png", new FileOutputStream("aa.png"));
       }
   
   
   }
   

2. 在controller层下创建路由

@GetMapping("/code")
    public void getVerification(HttpSession session, HttpServletResponse response) throws IOException {
        //生成验证码
        String securityCode = ValidateImageCodeUtils.getSecurityCode();
        //生成验证码图片
        BufferedImage image = ValidateImageCodeUtils.createImage(securityCode);
        //存入session
        session.setAttribute("code",securityCode);
        //响应图片
        ServletOutputStream os = response.getOutputStream();
        ImageIO.write(image,"png",os);
    }

接着访问自己的端口就可以看到验证码