图形验证码（基础）

一、生成图形验证码

　　1、根据随机数生成图片

　　2、将随机数存储到session中

　　3、将生成的图片写到接口的响应中

　　基类：

package com.nxz.security.core.validatecode;

import lombok.Data;

import java.awt.image.BufferedImage;
import java.time.LocalDateTime;

@Data
public class ImageCode {

    private BufferedImage image;

    private String code;//随机数

    private LocalDateTime expireTime;

    public ImageCode(BufferedImage image, String code, int expireIn) {
        this.image = image;
        this.code = code;
        this.expireTime = LocalDateTime.now().plusSeconds(expireIn);
    }

    public ImageCode(BufferedImage image, String code, LocalDateTime expireTime) {
        this.image = image;
        this.code = code;
        this.expireTime = expireTime;
    }
}

　　控制层：

package com.nxz.security.core.controller;

import com.nxz.security.core.validatecode.ImageCode;
import org.springframework.social.connect.web.HttpSessionSessionStrategy;
import org.springframework.social.connect.web.SessionStrategy;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.context.request.ServletWebRequest;

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

@RestController
public class ValidateCodeController {

    private static final String SESSION_KEY = "SESSION_KEY_IMAGE_CODE";

    private SessionStrategy sessionStrategy = new HttpSessionSessionStrategy();

    @GetMapping("/code/image")
    public void createCode(HttpServletRequest request, HttpServletResponse response) throws IOException {
        //生成图片
        ImageCode imageCode = createImageCode(request);

        //将随机数存到session中
        sessionStrategy.setAttribute(new ServletWebRequest(request), SESSION_KEY, imageCode);
        ImageIO.write(imageCode.getImage(), "JPEG", response.getOutputStream());
    }

    private ImageCode createImageCode(HttpServletRequest request) {
        // 在内存中创建图象
        int width = 85, height = 20;
        BufferedImage image = new BufferedImage(width, height,
                BufferedImage.TYPE_INT_RGB);
        // 获取图形上下文
        Graphics g = image.getGraphics();
        // 生成随机类
        Random random = new Random();
        // 设定背景色
        g.setColor(getRandColor(200, 250));
        g.fillRect(0, 0, width, height);
        // 设定字体
        g.setFont(new Font("Times New Roman", Font.PLAIN, 18));
        // 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到
        g.setColor(getRandColor(160, 200));
        for (int i = 0; i < 155; i++) {
            int x = random.nextInt(width);
            int y = random.nextInt(height);
            int xl = random.nextInt(12);
            int yl = random.nextInt(12);
            g.drawLine(x, y, x + xl, y + yl);
        }
        // 取随机产生的认证码(6位数字)
        String sRand = "";
        for (int i = 0; i < 6; i++) {
            String rand = String.valueOf(random.nextInt(10));
            sRand += rand;
            // 将认证码显示到图象中
            g.setColor(new Color(20 + random.nextInt(110), 20 + random
                    .nextInt(110), 20 + random.nextInt(110)));
            // 调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
            g.drawString(rand, 13 * i + 6, 16);
        }

        // 图象生效
        g.dispose();

        return new ImageCode(image, sRand, 60);
    }

    /*
     * 给定范围获得随机颜色
     */
    private Color getRandColor(int fc, int bc) {
        Random random = new Random();
        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);
    }
}

　　页面：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>自定义登录页面</title>
</head>
<body>

<h2>自定义登录页面</h2>

<form action="/authentication/form" method="POST">
    <table>
        <tr>
            <td>用户名：</td>
            <td><input type="text" name="username"></td>
        </tr>

        <tr>
            <td>密码：</td>
            <td><input type="password" name="password"></td>
        </tr>
        <tr>
            <td>图形验证码：</td>
            <td>
                <input type="text" name="imagecode">
                <img src="/code/image" alt="">
            </td>
        </tr>
        <tr>
            <td colspan="2">
                <button type="submit">登录</button>
            </td>
        </tr>
    </table>


</form>

</body>
</html>

　　效果：

ps：图形验证码的各种参数都可以配置到application.yml中，并且图形验证码生成器可以配置为可配置类，默认实现一种，动态配置覆盖默认配置

图形验证码（基础）

猜你喜欢