java(Spring boot)实现获取验证码图片

小咪咪 2023-09-29 17:26 4阅读 0赞

#### 文章目录 ####

*   *  一、工具类代码
     *  二、工具类调用
     *   *  1、获取验证码接口
         *  2、获取验证码接口用于登录验证

### 一、工具类代码 ###

创建CreateVerifiCodeImage类，将下面代码复制到该类中：

import java.awt.*;
    import java.awt.image.BufferedImage;
    import java.util.Random;
    
    /**
     * @project: ssm_sms
     * @description: 绘制验证码图片
     */
    public class CreateVerifiCodeImage {
        
    
        private static int WIDTH = 90;
        private static int HEIGHT = 35;
        private static int FONT_SIZE = 20; //字符大小
        private static char[] verifiCode; //验证码
        private static BufferedImage verifiCodeImage; //验证码图片
    
        /**
         * @description: 获取验证码图片
         * @param: no
         * @return: java.awt.image.BufferedImage
         */
        public static BufferedImage getVerifiCodeImage() {
        
            verifiCodeImage = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_BGR);// create a image
            Graphics graphics = verifiCodeImage.getGraphics();
    
            verifiCode = generateCheckCode();
            drawBackground(graphics);
            drawRands(graphics, verifiCode);
    
            graphics.dispose();
    
            return verifiCodeImage;
        }
    
        /**
         * @description: 获取验证码
         * @param: no
         * @return: char[]
         */
        public static char[] getVerifiCode() {
        
            return verifiCode;
        }
    
        /**
         * @description: 随机生成验证码
         * @param: no
         * @return: char[]
         */
        private static char[] generateCheckCode() {
        
            String chars = "0123456789abcdefghijklmnopqrstuvwxyz" + "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
            char[] rands = new char[4];
            for (int i = 0; i < 4; i++) {
        
                int rand = (int) (Math.random() * (10 + 26 * 2));
                rands[i] = chars.charAt(rand);
            }
            return rands;
        }
    
        /**
         * @description: 绘制验证码
         * @param: g
         * @param: rands
         * @return: void
         */
        private static void drawRands(Graphics g, char[] rands) {
        
            g.setFont(new Font("Console", Font.BOLD, FONT_SIZE));
    
            for (int i = 0; i < rands.length; i++) {
        
    
                g.setColor(getRandomColor());
                g.drawString("" + rands[i], i * FONT_SIZE + 10, 25);
            }
        }
    
        /**
         * @description: 绘制验证码图片背景
         * @param: g
         * @return: void
         */
        private static void drawBackground(Graphics g) {
        
    
            g.setColor(Color.white);
            g.fillRect(0, 0, WIDTH, HEIGHT);
    
            // 绘制验证码干扰点
            for (int i = 0; i < 200; i++) {
        
                int x = (int) (Math.random() * WIDTH);
                int y = (int) (Math.random() * HEIGHT);
                g.setColor(getRandomColor());
                g.drawOval(x, y, 1, 1);
    
            }
        }
    
    
        /**
         * @description: 获取随机颜色
         * @param: no
         * @return: java.awt.Color
         */
        private static Color getRandomColor() {
        
            Random ran = new Random();
            return new Color(ran.nextInt(220), ran.nextInt(220), ran.nextInt(220));
        }
    }

### 二、工具类调用 ###

#### 1、获取验证码接口 ####

通过调用工具类getVerifiCodeImage 即可获取到验证码图片

@GetMapping("/getVerifiCodeImage")
        public void getVerifiCodeImage(HttpServletRequest request, HttpServletResponse response){
        
            // 获取图片
            BufferedImage verifiCodeImage = CreateVerifiCodeImage.getVerifiCodeImage();
            
            // 将验证码图片响应给浏览器
            try {
        
                ImageIO.write(verifiCodeImage,"JPEG",response.getOutputStream());
            } catch (IOException e) {
        
                e.printStackTrace();
            }
        }

运行项目，打开浏览器访问该接口地址，页面就会显示生成的验证码图片，刷新验证码，获取的验证码也会随之更新：  
![在这里插入图片描述][7baab83178c94f0a99f9dd9f15266c20.png]

#### 2、获取验证码接口用于登录验证 ####

获取验证码显示在前端后，但验证码功能如登录功能一般还要验证输入的验证码是否正确，即在获取验证码图片的同时，还需获取验证码图片上的值，并将其存储到HttpServletRequest的session域中，用于登录验证。

@GetMapping("/getVerifiCodeImage")
        public void getVerifiCodeImage(HttpServletRequest request, HttpServletResponse response){
        
            // 获取图片
            BufferedImage verifiCodeImage = CreateVerifiCodeImage.getVerifiCodeImage();
            // 获取图片上的验证码
            String verifiCode =new String( CreateVerifiCodeImage.getVerifiCode());
            // 将验证码文本放入session域,为下一次验证做准备
            HttpSession session = request.getSession();
            session.setAttribute("verifiCode",verifiCode);
            // 将验证码图片响应给浏览器
    
            try {
        
                ImageIO.write(verifiCodeImage,"JPEG",response.getOutputStream());
            } catch (IOException e) {
        
                e.printStackTrace();
            }
        }

在登录接口从HttpServletRequest中获取session里存储的验证码值，并与用户输入的验证码进行校验，校验用户输入的验证码正确即再验证登录的账号即密码是否正确：

@PostMapping("/login")
        public Result login(@RequestBody LoginForm loginForm, HttpServletRequest request){
        
            // 验证码校验
            HttpSession session = request.getSession();
            String sessionVerifiCode = (String)session.getAttribute("verifiCode");
            String loginVerifiCode = loginForm.getVerifiCode();
            if("".equals(sessionVerifiCode) || null == sessionVerifiCode){
        
                return Result.fail().message("验证码失效,请刷新后重试");
            }
            if (!sessionVerifiCode.equalsIgnoreCase(loginVerifiCode)){
        
                return Result.fail().message("验证码输入错误，请重新输入！");
            }
            // 从session域中移除现有验证码
            session.removeAttribute("verifiCode");
            
            // 以下可继续进行登录的账号密码等验证逻辑
            
        }

[7baab83178c94f0a99f9dd9f15266c20.png]: https://img-blog.csdnimg.cn/7baab83178c94f0a99f9dd9f15266c20.png