SpringBoot 实现“图片验证码”登录验证 功能 【简单实例】

效果图 ：

目录结构

一、工具类

package com.zbw.utils;

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

        // 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
        Graphics g = image.getGraphics();

        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++) {
            drawLine(g);
        }

        // 绘制随机字符
        String randomString = "";

        for (int i = 1; i <= stringNum; i++) {
            randomString = drawString(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 drawString(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 drawLine(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));
    }
}

二、controller

package com.zbw.action;

import com.songo.utils.RandomValidateCodeUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

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

@RestController
@RequestMapping("/login")
public class PicVerifyAction {
    private final static Logger logger = LoggerFactory.getLogger(PicVerifyAction.class);

    /**
     * 生成验证码
     */
    @RequestMapping(value = "/getVerify")
    public void getVerify(HttpServletRequest request, HttpServletResponse response) {

        try {

            //设置相应类型,告诉浏览器输出的内容为图片
            response.setContentType("image/jpeg");

            //设置响应头信息，告诉浏览器不要缓存此内容
            response.setHeader("Pragma", "No-cache");
            response.setHeader("Cache-Control", "no-cache");
            response.setDateHeader("Expire", 0);

            RandomValidateCodeUtil randomValidateCode = new RandomValidateCodeUtil();

            randomValidateCode.getRandomCode(request, response);//输出验证码图片方法

        } catch (Exception e) {

            logger.error("获取验证码失败>>>>   ", e);

        }

    }

    /**
     * 校验验证码
     */
    @RequestMapping(value = "/checkVerify", method = RequestMethod.POST, headers = "Accept=application/json")
    public boolean checkVerify(@RequestParam String verifyInput, HttpSession session) {
        try {

            //从session中获取随机数
            String inputStr = verifyInput;

            String random = (String) session.getAttribute("RANDOMVALIDATECODEKEY");

            if (random == null || "".equals(random) || !random.equalsIgnoreCase(inputStr)) {
                return false;
            } else {
                return true;
            }

        } catch (Exception e) {
            logger.error("验证码校验失败", e);
            return false;
        }
    }

}

三、前端 index.html

说明 ： 使用了 jquery.js

<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>登陆title>
head>

<style>
    #main_form {
        width: 300px;
        height: 200px;
        margin: 100px auto;

        background-color: #F0F0F0;
        border: 1px solid #c2c2c2;
    }

    #input_content {
        margin-top: 20px;
        text-align: center;
        border: 5px;
    }

    #verify_image, #submit_btn {
        text-align: center;
        margin: 20px auto;
    }
style>

<body>


<div id="main_form">
    <div id="input_content">
        <input autocomplete="off" autofocus id="verify_input" placeholder="请输入验证码" maxlength="4">
    div>
    <div id="verify_image">
        <img id="imgVerify" src="login/getVerify" alt="更换验证码" height="36" width="170" onclick="getVerify(this);">
    div>

    <div id="submit_btn">
        <input type="button" onclick="aVerify()" value="判断是否正确">
    div>
div>


body>
<script type="text/javascript" src="./js/jquery.min.js">script>

<script>


    function getVerify() {
        $("#verify_input").val("");
        $("#imgVerify").attr("src", 'login/getVerify?' + Math.random());//jquery方式
    }

    function aVerify() {
        let value = $("#verify_input").val();
        
        if (value.length < 4) {
            alert("验证码不足4位 , 请重新输入！！");
            return 0;
        }


            $.ajax({
                async: false,
                type: 'post',
                url: 'login/checkVerify',
                dataType: "json",
                data: {
                    verifyInput: value
                },
                success: function (result) {

                    if (result) {

                        if (confirm("验证成功, 再试一次 ！")) {
                            getVerify();
                        } else {
                            window.location.href = "https:www.baidu.com";
                        }

                    } else {
                        alert("验证失败 , 点击确定重新验证");
                        getVerify();
                    }
                    // window.location.reload();
                }
            });
    }


script>
html>