验证码 案例

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

/**
 * @author Mxhlin
 * @Email [email protected]
 * @Date 2022/09/27/20:48
 * @Version
 * @Description
 */
public class ZDemo03 {
    public static void main(String[] args) throws IOException {
        int len = 4;// 设置字母个数
        int width = len*26;// 设施图像长度
        int height = 50;// 设置图像高度
        // 后面让验证码随机获得这里面的字符
        String letter = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
        Random rand = new Random();
        StringBuilder sb = new StringBuilder();
        // 创建图形 真彩加透明
        BufferedImage bi = new BufferedImage(width,height,BufferedImage.TYPE_INT_ARGB);
        Graphics2D g = bi.createGraphics();// 画笔
        // 平滑
        g.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_GASP);
        g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        g.setRenderingHint(RenderingHints.KEY_STROKE_CONTROL, RenderingHints.VALUE_STROKE_DEFAULT);
        // 天秤背景颜色
        g.setColor(new Color(rand.nextInt(26)+220,rand.nextInt(26)+220,rand.nextInt(26)+220));
        g.fillRect(0,0,width,height);
        // 重新设置画笔颜色
        g.setColor(new Color(rand.nextInt(256),rand.nextInt(256),rand.nextInt(256)));
        for (int i = 0; i < len; i++) {// 循环验证码次数
            // 把letter的随机字符 组成单词
            String str = String.valueOf(letter.charAt(rand.nextInt(letter.length())));
            sb.append(str);// 添加再sb里面

            int x = i*25+5;// 设置x y
            int y = 35;

            Double aDouble = tiltT(g, x, y);// 倾斜

            // 设置字体
            g.setFont(new Font("微软雅黑",Font.PLAIN,rand.nextInt(20)+20));
            // 添加单词 设置位置
            g.drawString(str,x,y);
            // 反转一下
            g.rotate(-aDouble,x,y);
        }

        g.dispose();
        // 输出 文件格式  设置目录
        ImageIO.write(bi,"png",new File("xxx.png"));
        Runtime.getRuntime().exec("cmd /k start xxx.png");
    }

    public static Double tiltT(Graphics2D g,int x,int y){
        Random rand = new Random();
        double radianPercent = Math.PI * (rand.nextInt(35) / 180D);
        if (rand.nextBoolean())
            radianPercent = -radianPercent;
        g.rotate(radianPercent, x, y);
        return radianPercent;
    }
}