springboot验证码实现

1.首先是生成验证码

2.将生产的验证码保存在缓存中，只保存1-2分钟

缓存使用的是：ExpiringMap（一个轻量的Java缓存方式）

<dependency> 
<groupId>net.jodah</groupId> 
<artifactId>expiringmap</artifactId> 
<version>0.5.8</version> 
</dependency>

验证码的工具类：

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.util.Random;


/*对图片进行处理的类和方法*/
public class VerifyCode {

    public static  String drawRandomText(int width,int height, BufferedImage verifyImg) {

        Graphics2D graphics = (Graphics2D)verifyImg.getGraphics();

        graphics.setColor(Color.WHITE);//设置画笔颜色-验证码背景色

        graphics.fillRect(0, 0, width, height);//填充背景

        graphics.setFont(new Font("微软雅黑", Font.BOLD, 40));

//        //数字和大小写字母的组合
//        String baseNumLetter=  "123456789abcdefghijklmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ";

        //数字和小写字母的组合
        String baseNumLetter=  "123456789abcdefghijklmnopqrstuvwxyz";

//        //纯数字组合
//        String baseNumLetter=  "123456789";

        StringBuffer sBuffer = new StringBuffer();

        int x = 10;  //旋转原点的 x 坐标

        String ch = "";

        Random random = new Random();

        for(int i = 0;i < 4;i++){

            graphics.setColor(getRandomColor());

            //设置字体旋转角度

            int degree = random.nextInt() % 20;  //角度小于20度

            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 <3; 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<20;i++){

            int x1 = random.nextInt(width);

            int y1 = random.nextInt(height);

            graphics.setColor(getRandomColor());

            graphics.fillRect(x1, y1, 2,2);

        }

        return sBuffer.toString();

    }

    /**
     * 随机取色
     */

    private static Color getRandomColor() {

        Random ran = new Random();

        Color color = new Color(ran.nextInt(256),

                ran.nextInt(256), ran.nextInt(256));

        return color;

    }

}

验证码接口：

import com.sws.nlflow.portal.util.ExpiringMap;
import com.sws.nlflow.portal.util.VerifyCode;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.List;
import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

/**
 * 验证码处理接口
 */
@Slf4j
@Controller
@RequestMapping("/api")
public class VerifyCodeController {


    @RequestMapping("/getVerifyCode")
    public void getVerificationCode(HttpServletResponse response, HttpServletRequest request) {

        try {

            int width = 200;

            int height = 69;

            BufferedImage verifyImg = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

            //生成对应宽高的初始图片
            //功能是生成验证码字符并加上噪点，干扰线，返回值为验证码字符
            String randomText = VerifyCode.drawRandomText(width, height, verifyImg);

//          request.getSession().setAttribute("verifyCode", randomText);

            //获取ExpiringMap，将验证码保存在此处
            net.jodah.expiringmap.ExpiringMap<String, String> VerifyCodemap = ExpiringMap.map;
            VerifyCodemap.put(randomText, randomText);

            response.setContentType("image/png");//必须设置响应内容类型为图片，否则前台不识别

            OutputStream os = response.getOutputStream(); //获取文件输出流

            ImageIO.write(verifyImg, "png", os);//输出图片流

            os.flush();

            os.close();//关闭流

        } catch (IOException e) {

            log.error(e.getMessage());

            e.printStackTrace();

        }

    }
    
}

缓存工具类：

import java.io.Serializable;
import java.util.concurrent.TimeUnit;
import lombok.extern.slf4j.Slf4j;
import net.jodah.expiringmap.ExpirationPolicy;

/**
 * @author qushen
 * @create 2022/8/16 10:37
 */
@Slf4j
public class ExpiringMap implements Serializable {

    /**
     *
     * maxSize:map的最大长度,添加第1001个entry时,会导致第1个马上过期(即使没到过期时间)
     * expiration:过期时间和过期单位,设置过期时间,则永久有效.
     * expirationPolicy:过期策略的使用
     *      CREATED：  在每次更新元素时，过期倒计时清零
     *      ACCESSED： 在每次访问元素时，过期倒计时清零
     *
     * variableExpiration:允许更新过期时间值,如果不设置variableExpiration
     *      不允许更改过期时间,一旦执行更改过期时间的操作则会抛出UnsupportedOperationException异常
     * expirationListener:同步过期提醒
     * asyncExpirationListener:异步过期提醒
     * entryLoader:懒加载,调用get方法时若key不存在创建默认value
     *
     */

    public  static  net.jodah.expiringmap.ExpiringMap<String, String> map = net.jodah.expiringmap.ExpiringMap.builder()
            //设置过期时间
            .expiration(120, TimeUnit.SECONDS)
            //设置过期协议
            .expirationPolicy(ExpirationPolicy.ACCESSED)
            .variableExpiration()
            .build();

}

登录时候的验证方法：

      
      //传入参数： VerifyCode

       net.jodah.expiringmap.ExpiringMap<String, String> VerifyCodemap = ExpiringMap.map;



        if(!VerifyCodemap.containsKey(VerifyCode)){

            return new Response(Integer.valueOf(1), "验证码不正确！");
        }

springboot验证码实现

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