SpringBoot+Shiro登录验证码制作

用户登录常常要做防机器验证，所以使用到了随机验证码，防止机器刷

1.直接java内部自带的就行啦，也不需要用外部生成的api

生成验证码的工具类的写法：

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.Random;

/**
 * @author lrx
 * @description: TODO 验证码生成工具类
 * @date 2020/4/24 14:51
 */
public class CaptchaUtil {
    // 随机产生的字符串
    private static final String RANDOM_STRS = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";

    private static final String FONT_NAME = "Fixedsys";
    private static final int FONT_SIZE = 18;

    private Random random = new Random();

    private int width = 80;// 图片宽
    private int height = 25;// 图片高
    private int lineNum = 50;// 干扰线数量
    private int strNum = 4;// 随机产生字符数量

    /**
     * 生成随机图片
     */
    public BufferedImage genRandomCodeImage(StringBuffer randomCode) {
        // BufferedImage类是具有缓冲区的Image类
        BufferedImage image = new BufferedImage(width, height,
                BufferedImage.TYPE_INT_BGR);
        // 获取Graphics对象,便于对图像进行各种绘制操作
        Graphics g = image.getGraphics();
        // 设置背景色
        g.setColor(getRandColor(200, 250));
        g.fillRect(0, 0, width, height);

        // 设置干扰线的颜色
        g.setColor(getRandColor(110, 120));

        // 绘制干扰线
        for (int i = 0; i <= lineNum; i++) {
            drowLine(g);
        }
        // 绘制随机字符
        g.setFont(new Font(FONT_NAME, Font.ROMAN_BASELINE, FONT_SIZE));
        for (int i = 1; i <= strNum; i++) {
            randomCode.append(drowString(g, i));
        }
        g.dispose();
        return image;
    }

    /**
     * 给定范围获得随机颜色
     */
    private Color getRandColor(int fc, int bc) {
        if (fc > 255) {
            fc = 255;
        }
        if (bc > 255) {
            bc = 255;
        }
        int r = fc + random.nextInt(bc - fc);
        int g = fc + random.nextInt(bc - fc);
        int b = fc + random.nextInt(bc - fc);
        return new Color(r, g, b);
    }

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

    /**
     * 绘制干扰线
     */
    private void drowLine(Graphics g) {
        int x = random.nextInt(width);
        int y = random.nextInt(height);
        int x0 = random.nextInt(16);
        int y0 = random.nextInt(16);
        g.drawLine(x, y, x + x0, y + y0);
    }

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

    public static void main(String[] args) {
        CaptchaUtil tool = new CaptchaUtil();
        StringBuffer code = new StringBuffer();
        BufferedImage image = tool.genRandomCodeImage(code);
        System.out.println("lrx = " + code);
        try {
            // 将内存中的图片通过流动形式输出到客户端
            ImageIO.write(image, "JPEG", new FileOutputStream(new File(
                    "D:/lrx/tp/lrx.jpg")));
        } catch (Exception e) {
            e.printStackTrace();
        }

    }
}

2.因为用的springboot，咱们来写一个获取二维码的接口

/**
 * @author lrx
 * @description: TODO 验证码生成
 * @date 2020/4/24 16:03
 */

@Api(tags = "二维码生成")
@RequestMapping("/captcha")
@RestController
public class CaptchaController {
    public static final String KEY_CAPTCHA = "KEY_CAPTCHA";
    /**
    *  验证码生成
    * */
    @GetMapping("imageGeneration")
    public void imageGeneration(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
        // 设置相应类型,告诉浏览器输出的内容为图片
        response.setContentType("image/jpeg");
        // 不缓存此内容
        response.setHeader("Pragma", "No-cache");
        response.setHeader("Cache-Control", "no-cache");
        response.setDateHeader("Expire", 0);
        try {

            HttpSession session = request.getSession();

            CaptchaUtil tool = new CaptchaUtil();
            StringBuffer code = new StringBuffer();
            BufferedImage image = tool.genRandomCodeImage(code);
            session.removeAttribute(KEY_CAPTCHA);
            session.setAttribute(KEY_CAPTCHA, code.toString());

            // 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) {
            e.printStackTrace();
        }

    }
}

 3.因为咱们用了shiro所以要去掉拦截，匿名访问

注：

聊到这里，我这边就讲一哈shiro的小知识吧，关于怎么去拦截

URL匹配规则

（1）“?”：匹配一个字符，如”/admin?”，将匹配“ /admin1”、“/admin2”，但不匹配“/admin”

（2）“*”：匹配零个或多个字符串，如“/admin*”，将匹配“ /admin”、“/admin123”，但不匹配“/admin/1”

（3）“**”：匹配路径中的零个或多个路径，如“/admin/**”，将匹配“/admin/a”、“/admin/a/b”

按照上面即可

4.接下来就是登录了

@PostMapping
    @ApiOperation(value = "后台登录")
    @OperationLog(desc = "后台用户登录", systemModul = SystemModuleEnum.SYSTEM)
    public ResponseUtil<UserLoginRetrunInfoVO> verify(@Valid LoginVerifyDTO loginVerifyDTO) {

        return ResponseUtil.responseSuccess(userService.longin(loginVerifyDTO, LoginUserTypeConst.LOGIN_BACK));
    }

5.参数对象类

@Getter
@Setter
@ToString
public class LoginVerifyDTO {

    /**
     * 用户名
     */
    @NotBlank(message = "用户名不能为空")
    @ApiModelProperty(value = "用户名", required = true)
    private String username;

    /**
     * 密码
     */
    @NotBlank(message = "密码不能为空")
    @ApiModelProperty(value = "密码", required = true)
    private String password;

    /**
     * 密码
     */
    @NotBlank(message = "验证码不能为空")
    @ApiModelProperty(value = "验证码", required = true)
    private String captcha;
}

注：

访问如下

登录如下