在idea中使用spring-boot实现验证码

1.在idea中创建spring-boot项目

包结构

2.验证码图片生成的工具类

package com.yxh.yanzhenma.util;


import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.Random;


public class RandomValidateCodeUtil {

    public static final String RANDOMCODEKEY= "RANDOMVALIDATECODEKEY";//放到session中的key
    private String randString = "0123456789";//随机产生只有数字的字符串 private String
    //private String randString = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";//随机产生只有字母的字符串
    //private String randString = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";//随机产生数字与字母组合的字符串
    private int width = 95;// 图片宽
    private int height = 25;// 图片高
    private int lineSize = 40;// 干扰线数量
    private int stringNum = 4;// 随机产生字符数量


    private static final Logger logger = (Logger) LoggerFactory.getLogger(RandomValidateCodeUtil.class);

    private Random random = new Random();

    /**
     * 获得字体
     */
    private Font getFont() {
        return new Font("Fixedsys", Font.CENTER_BASELINE, 18);
    }

    /**
     * 获得颜色
     */
    private Color getRandColor(int fc, int bc) {
        if (fc > 255)
            fc = 255;
        if (bc > 255)
            bc = 255;
        int r = fc + random.nextInt(bc - fc - 16);
        int g = fc + random.nextInt(bc - fc - 14);
        int b = fc + random.nextInt(bc - fc - 18);
        return new Color(r, g, b);
    }

    /**
     * 生成随机图片
     */
    public void getRandcode(HttpServletRequest request, HttpServletResponse response) {
        HttpSession session = request.getSession();
        // BufferedImage类是具有缓冲区的Image类,Image类是用于描述图像信息的类
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR);
        Graphics g = image.getGraphics();// 产生Image对象的Graphics对象,改对象可以在图像上进行各种绘制操作
        g.fillRect(0, 0, width, height);//图片大小
        g.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 18));//字体大小
        g.setColor(getRandColor(110, 133));//字体颜色
        // 绘制干扰线
        for (int i = 0; i <= lineSize; i++) {
            drowLine(g);
        }
        // 绘制随机字符
        String randomString = "";
        for (int i = 1; i <= stringNum; i++) {
            randomString = drowString(g, randomString, i);
        }
        logger.info(randomString);
        //将生成的随机字符串保存到session中
        session.removeAttribute(RANDOMCODEKEY);
        session.setAttribute(RANDOMCODEKEY, randomString);
        g.dispose();
        try {
            // 将内存中的图片通过流动形式输出到客户端
            ImageIO.write(image, "JPEG", response.getOutputStream());
        } catch (Exception e) {
            logger.error("将内存中的图片通过流动形式输出到客户端失败>>>>   ", e);
        }

    }

    /**
     * 绘制字符串
     */
    private String drowString(Graphics g, String randomString, int i) {
        g.setFont(getFont());
        g.setColor(new Color(random.nextInt(101), random.nextInt(111), random
                .nextInt(121)));
        String rand = String.valueOf(getRandomString(random.nextInt(randString
                .length())));
        randomString += rand;
        g.translate(random.nextInt(3), random.nextInt(3));
        g.drawString(rand, 13 * i, 16);
        return randomString;
    }

    /**
     * 绘制干扰线
     */
    private void drowLine(Graphics g) {
        int x = random.nextInt(width);
        int y = random.nextInt(height);
        int xl = random.nextInt(13);
        int yl = random.nextInt(15);
        g.drawLine(x, y, x + xl, y + yl);
    }

    /**
     * 获取随机的字符
     */
    public String getRandomString(int num) {
        return String.valueOf(randString.charAt(num));
    }
}

　3.在controller中调用验证码生成的工具类，并传给前端

package com.yxh.yanzhenma.controller;


import com.yxh.yanzhenma.util.RandomValidateCodeUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@RestController
@EnableAutoConfiguration
public class YzmPictureController {
    Logger logger = (Logger) LoggerFactory.getLogger(YzmPictureController.class);
    /**
     * 生成验证码
     * */
    @RequestMapping(value = "/getVerify")
    public void getVerify(HttpServletRequest request , HttpServletResponse response){
    try{
        response.setContentType("image/jpeg");//设置相应类型，告诉浏览器输出的内容为图片
        response.setHeader("Pragma","No-cache");//设置响应头信息，告诉浏览器不要缓存此信息
        response.setHeader("Cache-Control","no-cache");
        response.setDateHeader("Explire",0);
        RandomValidateCodeUtil randomValidateCodeUtil = new RandomValidateCodeUtil();
        randomValidateCodeUtil.getRandcode(request,response);//输出验证码图片的方法
        }catch (Exception e){
        logger.error("获取验证码失败>>>>>",e);
        }
    }
}

　　4.前端页面的显示

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>验证码</title>
    <script>
        //获取验证码
        function getVerify(obj){
            obj.src = httpurl + "/sys/getVerify?"+Math.random();
        }
    </script>
</head>
<body>
<div class="row">
    <div class="col-xs-6 pull_left">
        <div class="form-group">
            <input class="form-control" type="tel" id="verify_input" placeholder="请输入验证码" maxlength="4">
        </div>
    </div>
    <div class="col-xs-6 pull_left">
        <a href="javascript:void(0);" title="点击更换验证码">
            <img id="imgVerify" src="" alt="更换验证码" height="36" width="100%" onclick="getVerify(this);">
        </a>
    </div>
</div>

</body>
</html>