验证码工具类-蒲公英云

验证码工具类

在这里插入图片描述

package com.sky.ospringboot.common.utils;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.util.Random;
import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import lombok.extern.log4j.Log4j2;
@Log4j2
public class ValidateCodeUtil { 
    public static final String RANDOMCODEKEY = "RANDOMVALIDATECODEKEY";// 放到session中的key
    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 getRandcode(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);
        Graphics g = image.getGraphics();// 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
        g.fillRect(0, 0, width, height);// 图片大小
        g.setFont(new Font("Default", 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++) { 
            drowLine(g);
        }
        // 绘制随机字符
        String randomString = "";
        for (int i = 1; i <= stringNum; i++) { 
            randomString += drowString(g, getRandomString(), i);
        }
        log.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) { 
            log.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 drowString(Graphics g, String rand, int i) { 
        g.setFont(getFont());
        g.setColor(new Color(random.nextInt(101), random.nextInt(111), random.nextInt(121)));
        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 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() { 
        StringBuffer sb = new StringBuffer();
        sb.append("123456789");
        sb.append("ABCDEFGHJKLMNPQRSTUVWXYZ");
        sb.append("abcdefghjklmnpqrstuvwxyz");
        int nextInt = random.nextInt(sb.length());
        return sb.charAt(nextInt) + "";
    }
}