原SpringBoot+Thymleaf项目初入(五) - 图片验证码

1. 验证码工具类

1. 新建包utils
2. 新建VerifyCodeUtil类

package cn.coralcloud.ims.utils;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Arrays;
import java.util.Random;

/**
 * @author c-geff
 */
public class VerifyCodeUtil {

    /**
     * 使用到Algerian字体，系统里没有的话需要安装字体，字体只显示大写，去掉了1,0,i,o几个容易混淆的字符
     */
    private static final String VERIFY_CODES = "23456789ABCDEFGHJKLMNPQRSTUVWXYZ";
    private static Random random = new Random();


    /**
     * 使用系统默认字符源生成验证码
     * @param verifySize    验证码长度
     * @return
     */
    public static String generateVerifyCode(int verifySize){
        return generateVerifyCode(verifySize, VERIFY_CODES);
    }
    /**
     * 使用指定源生成验证码
     * @param verifySize    验证码长度
     * @param sources   验证码字符源
     * @return
     */
    public static String generateVerifyCode(int verifySize, String sources){
        if(sources == null || sources.length() == 0){
            sources = VERIFY_CODES;
        }
        int codesLen = sources.length();
        Random rand = new Random(System.currentTimeMillis());
        StringBuilder verifyCode = new StringBuilder(verifySize);
        for(int i = 0; i < verifySize; i++){
            verifyCode.append(sources.charAt(rand.nextInt(codesLen-1)));
        }
        return verifyCode.toString();
    }

    /**
     * 生成随机验证码文件,并返回验证码值
     * @param w
     * @param h
     * @param outputFile
     * @param verifySize
     * @return
     * @throws IOException
     */
    public static String outputVerifyImage(int w, int h, File outputFile, int verifySize) throws IOException{
        String verifyCode = generateVerifyCode(verifySize);
        outputImage(w, h, outputFile, verifyCode);
        return verifyCode;
    }

    /**
     * 输出随机验证码图片流,并返回验证码值
     * @param w
     * @param h
     * @param os
     * @param verifySize
     * @return
     * @throws IOException
     */
    public static String outputVerifyImage(int w, int h, OutputStream os, int verifySize) throws IOException{
        String verifyCode = generateVerifyCode(verifySize);
        outputImage(w, h, os, verifyCode);
        return verifyCode;
    }

    /**
     * 生成指定验证码图像文件
     * @param w
     * @param h
     * @param outputFile
     * @param code
     * @throws IOException
     */
    public static void outputImage(int w, int h, File outputFile, String code) throws IOException{
        if(outputFile == null){
            return;
        }
        File dir = outputFile.getParentFile();
        if(!dir.exists()){
            dir.mkdirs();
        }
        try{
            outputFile.createNewFile();
            FileOutputStream fos = new FileOutputStream(outputFile);
            outputImage(w, h, fos, code);
            fos.close();
        } catch(IOException e){
            throw e;
        }
    }

    /**
     * 输出指定验证码图片流
     * @param w
     * @param h
     * @param os
     * @param code
     * @throws IOException
     */
    public static void outputImage(int w, int h, OutputStream os, String code) throws IOException{
        int verifySize = code.length();
        BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
        Random rand = new Random();
        Graphics2D g2 = image.createGraphics();
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,RenderingHints.VALUE_ANTIALIAS_ON);
        Color[] colors = new Color[5];
        Color[] colorSpaces = new Color[] { Color.WHITE, Color.CYAN,
                Color.GRAY, Color.LIGHT_GRAY, Color.MAGENTA, Color.ORANGE,
                Color.PINK, Color.YELLOW };
        float[] fractions = new float[colors.length];
        for(int i = 0; i < colors.length; i++){
            colors[i] = colorSpaces[rand.nextInt(colorSpaces.length)];
            fractions[i] = rand.nextFloat();
        }
        Arrays.sort(fractions);
        // 设置边框色
        g2.setColor(Color.GRAY);
        g2.fillRect(0, 0, w, h);

        Color c = getRandColor(200, 250);
        // 设置背景色
        g2.setColor(c);
        g2.fillRect(0, 2, w, h-4);

        //绘制干扰线
        Random random = new Random();
        // 设置线条的颜色
        g2.setColor(getRandColor(160, 200));
        int loop = 20;
        for (int i = 0; i < loop; i++) {
            int x = random.nextInt(w - 1);
            int y = random.nextInt(h - 1);
            int xl = random.nextInt(6) + 1;
            int yl = random.nextInt(12) + 1;
            g2.drawLine(x, y, x + xl + 40, y + yl + 20);
        }

        // 添加噪点// 噪声率
        float yawpRate = 0.05f;
        int area = (int) (yawpRate * w * h);
        for (int i = 0; i < area; i++) {
            int x = random.nextInt(w);
            int y = random.nextInt(h);
            int rgb = getRandomIntColor();
            image.setRGB(x, y, rgb);
        }
        // 使图片扭曲
        shear(g2, w, h, c);

        g2.setColor(getRandColor(100, 160));
        int fontSize = h-4;
        Font font = new Font("Algerian", Font.ITALIC, fontSize);
        g2.setFont(font);
        char[] chars = code.toCharArray();
        for(int i = 0; i < verifySize; i++){
            AffineTransform affine = new AffineTransform();
            affine.setToRotation(Math.PI / 4 * rand.nextDouble() * (rand.nextBoolean() ? 1 : -1), (w / verifySize) * i + fontSize/2, h/2);
            g2.setTransform(affine);
            g2.drawChars(chars, i, 1, ((w-10) / verifySize) * i + 5, h/2 + fontSize/2 - 10);
        }

        g2.dispose();
        ImageIO.write(image, "jpg", os);
    }
    private static final Integer COLOR_MAX_INT = 255;
    private static Color getRandColor(int fc, int bc) {
        if (fc > COLOR_MAX_INT) {
            fc = COLOR_MAX_INT;
        }
        if (bc > COLOR_MAX_INT) {
            bc = COLOR_MAX_INT;
        }
        int r = fc + random.nextInt(bc - fc);
        int g = fc + random.nextInt(bc - fc);
        int b = fc + random.nextInt(bc - fc);
        return new Color(r, g, b);
    }

    private static int getRandomIntColor() {
        int[] rgb = getRandomRgb();
        int color = 0;
        for (int c : rgb) {
            color = color << 8;
            color = color | c;
        }
        return color;
    }

    private static int[] getRandomRgb() {
        int[] rgb = new int[3];
        int loop = 3;
        for (int i = 0; i < loop; i++) {
            rgb[i] = random.nextInt(255);
        }
        return rgb;
    }

    private static void shear(Graphics g, int w1, int h1, Color color) {
        shearx(g, w1, h1, color);
        sheary(g, w1, h1, color);
    }

    private static void shearx(Graphics g, int w1, int h1, Color color) {

        int period = random.nextInt(2);

        boolean borderGap = true;
        int frames = 1;
        int phase = random.nextInt(2);

        for (int i = 0; i < h1; i++) {
            double d = (double) (period >> 1)
                    * Math.sin((double) i / (double) period
                            + (6.2831853071795862D * (double) phase)
                            / (double) frames);
            g.copyArea(0, i, w1, 1, (int) d, 0);
            if (borderGap) {
                g.setColor(color);
                g.drawLine((int) d, i, 0, i);
                g.drawLine((int) d + w1, i, w1, i);
            }
        }

    }

    private static void sheary(Graphics g, int w1, int h1, Color color) {

        int period = random.nextInt(40) + 10;

        boolean borderGap = true;
        int frames = 20;
        int phase = 7;
        for (int i = 0; i < w1; i++) {
            double d = (double) (period >> 1)
                    * Math.sin((double) i / (double) period
                            + (6.2831853071795862D * (double) phase)
                            / (double) frames);
            g.copyArea(i, 0, 1, h1, 0, (int) d);
            if (borderGap) {
                g.setColor(color);
                g.drawLine(i, (int) d, i, 0);
                g.drawLine(i, (int) d + h1, i, h1);
            }

        }

    }
}

2. UserController新增验证码接口

2.1 新增captcha方法

    @GetMapping("/captcha")
    public void captcha(HttpServletResponse response, HttpSession session){
        String code = VerifyCodeUtil.generateVerifyCode(4);
        session.setAttribute(SessionKey.ADMIN_CAPTCHA_KEY, code);
        try {
            VerifyCodeUtil.outputImage(150, 50, response.getOutputStream(), code);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

2.2 修改login方法, 增加验证

下方为最终的登录验证方法:

    @PostMapping("/login")
    public ModelAndView login(String email, String password, String captcha, HttpSession session){
        String sessionCaptcha = (String)session.getAttribute(SessionKey.ADMIN_CAPTCHA_KEY);
        ModelAndView view = new ModelAndView();
        view.setViewName("user/login");
        // 将email和password写回到页面, 使得登录失败时输入的账号密码不会丢失
        view.addObject("email", email);
        view.addObject("password", password);
        if(StringUtils.isEmpty(captcha) || !Objects.equals(captcha, sessionCaptcha)){
            view.addObject("errmsg", "验证码错误! ");
            return view;
        }
        User user = userService.login(email, password);
        if(user != null){
            session.setAttribute(SessionKey.ADMIN_USER_KEY, user);
            view.setViewName("redirect:/index");
            return view;
        }
        view.addObject("errmsg", "用户名或密码错误! ");
        return view;
    }

注: 此处将Session的Key值通过一个常量类SessionKey保存

2.3 SessionKey类

在utils包下新建SessionKey类

package cn.coralcloud.ims.utils;

/**
 * @author c-geff
 * @name SessionKey
 * @description
 * @date 2020-11-04 10:12
 */
public class SessionKey {

    public static final String ADMIN_USER_KEY = "AdminUserKey";

    public static final String ADMIN_CAPTCHA_KEY = "AdminLoginCaptchaCode";
}

3. 修改login.ftl

3.1 引入jquery

1. 下载jqeury文件 jquery.min.js
2. 在/static/js文件夹下新建jquery文件夹, 将jquery.min.js复制到文件夹下
3. 修改login.ftl文件, 最终login.ftl内容为下:

   <!doctype html>
   <html lang="en" xmlns:th="http://www.thymeleaf.org">
   <head>
    <meta charset="UTF-8">
    <meta name="viewport"
          content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <link type="text/css" rel="stylesheet" href="/static/css/main.css">
    <link type="text/css" rel="stylesheet" href="/static/css/login.css">
    <script src="/static/js/jquery/jquery.min.js" type="application/javascript" ></script>
    <title>用户登录</title>
   </head>
   <body>
    <div class="login-container">
        <form action="/user/login" method="post">
            <div>
                <h3>用户登录</h3>
            </div>
            <div class="ims-form-item">
                <label class="ims-form-label" for="email">登录邮箱</label>
                <input class="ims-form-input" id="email" autocomplete="off" th:value="${email}" placeholder="请输入邮箱" type="text" name="email">
            </div>
            <div class="ims-form-item">
                <label class="ims-form-label" for="password">登录密码</label>
                <input class="ims-form-input" id="password" autocomplete="new-password" th:value="${password}" placeholder="请输入密码" type="password" name="password">
            </div>
            <div class="ims-form-item">
                <label class="ims-form-label" for="captcha">图片验证</label>
                <input class="ims-form-input" id="captcha" type="text" placeholder="请输入图片验证码" name="captcha">
                <img src="/user/captcha" class="captcha" alt="图片验证码">
            </div>
            <p class="errormsg" th:if="${errmsg} != null" th:text="${errmsg}"></p>
            <div><button type="submit" class="ims-button">登录</button></div>
        </form>
    </div>
   </body>
   <script type="application/javascript">
    $(document).ready(function () {
        $('img.captcha').click(function () {
            $(this).attr("src", "/user/captcha?_=" + new Date().getTime())
        })
    })
   </script>
   </html>

注, login.ftl变更如下:

1. head新增引入jquery.min.js
2. input新增读取前面保存的email和password
3. 新增图片验证码输入框及图片
4. 新建图片点击监听事件, 更换图片验证码

4. 修改样式

login.css

#captcha{
    width: 100px;
    border-top-right-radius: 0;
    border-bottom-right-radius: 0;
}

.captcha{
    width: 1px;
    flex: 1;
    height: 42px;
    cursor: pointer;
    border-top-right-radius: 4px;
    border-bottom-right-radius: 4px;
}

5. 最终效果