Spring Boot实战之Redis缓存登录验证码

1.工具类

import lombok.experimental.UtilityClass;

import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.Random;

@UtilityClass
public class CaptchaUtil {


    private int width = 200;
    private int height = 50;


    public BufferedImage createImage(){
        //生成对应宽高的初始图片
        return  new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
    }

    public String drawRandomText(BufferedImage verifyImg) {
        Graphics2D graphics = (Graphics2D) verifyImg.getGraphics();
        //设置画笔颜色-验证码背景色
        graphics.setColor(Color.WHITE);
        //填充背景
        graphics.fillRect(0, 0, width, height);
        graphics.setFont(new Font("微软雅黑", Font.PLAIN, 30));
        //数字和字母的组合
        String baseNumLetter = "123456789abcdefghijklmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ";
        StringBuilder sBuffer = new StringBuilder();
        //旋转原点的 x 坐标
        int x = 10;
        String ch = "";
        Random random = new Random();
        for (int i = 0; i < 4; i++) {
            graphics.setColor(getRandomColor());
            //设置字体旋转角度
            //角度小于30度
            int degree = random.nextInt() % 30;
            int dot = random.nextInt(baseNumLetter.length());
            ch = baseNumLetter.charAt(dot) + "";
            sBuffer.append(ch);
            //正向旋转
            graphics.rotate(degree * Math.PI / 180, x, 45);
            graphics.drawString(ch, x, 45);
            //反向旋转
            graphics.rotate(-degree * Math.PI / 180, x, 45);
            x += 48;
        }

        //画干扰线
        for (int i = 0; i < 6; i++) {
            // 设置随机颜色
            graphics.setColor(getRandomColor());
            // 随机画线
            graphics.drawLine(random.nextInt(width), random.nextInt(height), random.nextInt(width), random.nextInt(height));
        }
        //添加噪点
        for (int i = 0; i < 30; i++) {
            int x1 = random.nextInt(width);
            int y1 = random.nextInt(height);
            graphics.setColor(getRandomColor());
            graphics.fillRect(x1, y1, 2, 1);
        }
        return sBuffer.toString();
    }

    /**
     * 随机取色
     */
    private Color getRandomColor() {
        Random ran = new Random();
        return new Color(ran.nextInt(256), ran.nextInt(256), ran.nextInt(256));

    }
}

2.controller类

 @GetMapping("/captcha.jpg")
    public void captcha(HttpServletResponse response, HttpServletRequest request) throws IOException {
        response.setHeader("Cache-Control", "no-store, no-cache");
        response.setContentType("image/jpeg");
        // 生成图片验证码
        BufferedImage image = CaptchaUtil.createImage();
        // 生成文字验证码
        String randomText = CaptchaUtil.drawRandomText(image);
        // 保存到验证码到 redis 有效期两分钟
        String t = request.getParameter("t");
        redisTemplate.opsForValue().set(key + t, randomText.toLowerCase(), 2, TimeUnit.MINUTES);
        ServletOutputStream out = response.getOutputStream();
        ImageIO.write(image, "jpeg", out);
    }

3.前端代码

refreshCaptcha: function() {
      this.loginForm.code = ''
      this.loginForm.t = new Date().getTime()
      this.src = 'http://localhost:8081/captcha.jpg?t=' + this.loginForm.t
    }

4.redis配置

#Redis配置
## Redis数据库索引（默认为0）
spring.redis.database=1
# Redis服务器地址
spring.redis.host=47.98.184.17
# Redis服务器连接端口
spring.redis.port=6379
# Redis服务器连接密码
spring.redis.password=root
# 连接池最大连接数（使用负值表示没有限制）
spring.redis.jedis.pool.max-active=8
# 连接池最大阻塞等待时间（使用负值表示没有限制）
spring.redis.jedis.pool.max-wait=30000ms
# 连接池中的最大空闲连接
spring.redis.jedis.pool.max-idle=8
# 连接池中的最小空闲连接
spring.redis.jedis.pool.min-idle=1
# 连接超时时间（毫秒）
spring.redis.timeout=6000ms