图形验证码生成器简单示例

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图形验证码生成器简单示例

1. 根据随机数生成图片
2. 将随机数存到Session中
3. 将生成的图片写到接口的响应中

• 验证码实体类

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

/**
 * @Project: tdt-security
 * @ClassName: ImageCode
 * @Author: Mr.superbeyone
 * @Time: 2018-12-02 16:11
 * @Description: 图形验证码封装
 **/

public class ImageCode {
    private BufferedImage image;

    private String code;

    private LocalDateTime expireTime;//过期时间

    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;
    }

    public BufferedImage getImage() {
        return image;
    }

    public void setImage(BufferedImage image) {
        this.image = image;
    }

    public String getCode() {
        return code;
    }

    public void setCode(String code) {
        this.code = code;
    }

    public LocalDateTime getExpireTime() {
        return expireTime;
    }

    public void setExpireTime(LocalDateTime expireTime) {
        this.expireTime = expireTime;
    }
}

• 图形验证码生成器

import org.apache.catalina.servlet4preview.http.HttpServletRequest;
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.HttpServletResponse;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

/**
 * @Project: tdt-security
 * @ClassName: ValidateCodeController
 * @Author: Mr.superbeyone
 * @Time: 2018-12-02 16:16
 * @Description: 图形验证码Controller
 **/
@RestController
public class ValidateCodeController {

    private static final String SESSION_KEY = "SESSION_KEY_IMAGE_CODE";
    //Spring 提供的操作Session的工具类
    private SessionStrategy sessionStrategy = new HttpSessionSessionStrategy();

    @GetMapping("/code/image")
    public void createCode(HttpServletRequest request, HttpServletResponse response) throws IOException {
        ImageCode imageCode = createImageCode(request);
        sessionStrategy.setAttribute(new ServletWebRequest(request), SESSION_KEY, imageCode);
        //将图片写出到响应中
        ImageIO.write(imageCode.getImage(), "JPEG", response.getOutputStream());
    }

    private ImageCode createImageCode(HttpServletRequest request) {
        int width = 60;
        int height = 23;
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);

        Graphics g = image.getGraphics();

        Random random = new Random();

        g.setColor(getRandColor(200, 250));
        g.fillRect(0, 0, width, height);
        g.setFont(new Font("Times New Roman", Font.ITALIC, 20));
        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);
        }

        String sRand = "";
        for (int i = 0; i < 4; i++) {
            String rand = String.valueOf(random.nextInt(10));
            sRand += rand;
            g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
            g.drawString(rand, 13 * i + 6, 16);
        }

        g.dispose();

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

    /**
     * 生成随机背景条纹
     *
     * @param fc
     * @param bc
     * @return
     */
    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);
    }
}

• 页面请求

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>登录</title>
</head>
<body>
<form action="/authentication/form" method="post">
    <table>
        <tr>
            <td>用户名：</td>
            <td><input type="text" name="username" id="username"></td>
        </tr>
        <tr>
            <td>密码：</td>
            <td><input type="password" name="password" id="password"></td>
        </tr>
        <tr>
            <td>图形验证码</td>
            <td><input type="text" name="imageCode" id="imageCode">
                <img src="/code/image" alt="">
            </td>
        </tr>
        <tr>
            <td colspan="2">
                <button type="submit">提交</button>
            </td>
        </tr>
    </table>

</form>
</body>
</html>

简单效果展示：