spring.turbo.module.misc.captcha.verysimple.SimpleCaptchaService Maven / Gradle / Ivy

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package spring.turbo.module.misc.captcha.verysimple;

import spring.turbo.module.misc.captcha.Captcha;
import spring.turbo.module.misc.captcha.CaptchaService;

import java.awt.*;
import java.awt.image.BufferedImage;
import java.util.Random;

/**
 * 简易实现，只适合极少数应用或非严肃的开发
 *
 * @author 应卓
 * @since 1.0.0
 */
public class SimpleCaptchaService implements CaptchaService {

    private static final Random RANDOM = new Random();
    private int length = 6;
    private int width = 100;
    private int height = 18;
    private String characters = "absdegkmnopwxABSDEGKMNOPWX23456789";
    private String font = "Times New Roman";

    /**
     * 默认构造方法
     */
    public SimpleCaptchaService() {
    }

    @Override
    public Captcha create() {
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        Graphics g = image.getGraphics();
        g.setColor(getRandomColor(200, 250));
        g.fillRect(1, 1, width - 1, height - 1);
        g.setColor(new Color(102, 102, 102));
        g.drawRect(0, 0, width - 1, height - 1);
        g.setFont(new Font(font, Font.PLAIN, 17));
        g.setColor(getRandomColor(160, 200));

        // 画随机线
        for (int i = 0; i < 155; i++) {
            int x = RANDOM.nextInt(width - 1);
            int y = RANDOM.nextInt(height - 1);
            int xl = RANDOM.nextInt(6) + 1;
            int yl = RANDOM.nextInt(12) + 1;
            g.drawLine(x, y, x + xl, y + yl);
        }

        // 从另一方向画随机线
        for (int i = 0; i < 70; i++) {
            int x = RANDOM.nextInt(width - 1);
            int y = RANDOM.nextInt(height - 1);
            int xl = RANDOM.nextInt(12) + 1;
            int yl = RANDOM.nextInt(6) + 1;
            g.drawLine(x, y, x - xl, y - yl);
        }

        // 生成随机数,并将随机数字转换为字母
        final StringBuilder captchaValue = new StringBuilder();
        for (int i = 0; i < length; i++) {
            char ch = getRandomChar();
            captchaValue.append(ch);
            g.setColor(new Color(20 + RANDOM.nextInt(110), 20 + RANDOM.nextInt(110), 20 + RANDOM.nextInt(110)));
            g.drawString(String.valueOf(ch), 15 * i + 10, 16);
        }
        g.dispose();

        return new Captcha(captchaValue.toString(), image);
    }

    private char getRandomChar() {
        if (characters == null || characters.isEmpty()) {
            return (char) (RANDOM.nextInt(26) + 65);
        } else {
            int index = RANDOM.nextInt(characters.length());
            return characters.charAt(index);
        }
    }

    private Color getRandomColor(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);
    }

    public void setLength(int length) {
        this.length = length;
    }

    public void setWidth(int width) {
        this.width = width;
    }

    public void setHeight(int height) {
        this.height = height;
    }

    public void setCharacters(String characters) {
        this.characters = characters;
    }

    public void setFont(String font) {
        this.font = font;
    }
}