java数字和中文算数验证码

效果图

本文代码 https://gitee.com/tothis/java-record/tree/master/src/main/java/com/example/captcha

• 中文实现参考 https://gitee.com/whvse/EasyCaptcha.git
• 数字实现参考 https://blog.csdn.net/weixin_34355881/article/details/90616273

代码如下

中文算法

package com.example.captcha;

import lombok.extern.slf4j.Slf4j;

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

/**
 * @author 李磊
 * @datetime 2020/7/9 20:10
 * @description
 */
@Slf4j
public class ChineseCaptcha {
    // 宽度
    private static final int IMAGE_WIDTH = 160;
    // 高度
    private static final int IMAGE_HEIGHT = 40;
    // 字体大小
    private static final int FONT_SIZE = 28;
    // 干扰线数量
    private static final int IMAGE_DISTURB_LINE_NUMBER = 15;
    // 后缀
    private static final String SUFFIX = "等于？";

    // 汉字数字
    private static final String SOURCE = "零一二三四五六七八九十乘除加减";

    // 计算类型
    private static final Map<String, Integer> calcType = new HashMap<>();
    private static final Random RANDOM = new Random();

    static {
        // 对应SOURCE下标
        calcType.put("*", 11);
        calcType.put("/", 12);
        calcType.put("+", 13);
        calcType.put("-", 14);
    }

    // 计算公式
    private String content;
    // 计算结果
    private int result;

    /**
     * 生成图像验证码
     */
    public BufferedImage create() {
        createMathChar();
        BufferedImage image = new BufferedImage(IMAGE_WIDTH, IMAGE_HEIGHT, BufferedImage.TYPE_INT_RGB);
        Graphics g = image.getGraphics();
        // 字体颜色
        g.setColor(Color.WHITE);
        // 背景颜色
        g.fillRect(0, 0, IMAGE_WIDTH, IMAGE_HEIGHT);
        g.setColor(color());
        // 图片边框
        g.drawRect(0, 0, IMAGE_WIDTH - 1, IMAGE_HEIGHT - 1);
        g.setColor(color());
        for (int i = 0; i < IMAGE_DISTURB_LINE_NUMBER; i++) {
            // 绘制干扰线
            int x1 = RANDOM.nextInt(IMAGE_WIDTH);
            int y1 = RANDOM.nextInt(IMAGE_HEIGHT);
            int x2 = RANDOM.nextInt(13);
            int y2 = RANDOM.nextInt(15);
            g.drawLine(x1, y1, x1 + x2, y1 + y2);
        }
        StringBuilder builder = new StringBuilder();
        for (int i = 0, j = content.length(); i < j; i++) {
            int index;
            if (i == 1) {
                index = calcType.get(String.valueOf(content.charAt(i)));
            } else {
                index = Integer.parseInt(String.valueOf(content.charAt(i)));
            }
            String ch = String.valueOf(SOURCE.charAt(index));
            builder.append(ch);
            drawString((Graphics2D) g, ch, i);
        }
        drawString((Graphics2D) g, SUFFIX, 3);
        content = builder.append(SUFFIX).toString();
        g.dispose();
        return image;
    }

    private void createMathChar() {
        StringBuilder number = new StringBuilder();
        // 10以内数字
        int xx = RANDOM.nextInt(10);
        int yy = RANDOM.nextInt(10);
        // 0~3 对应加减乘除
        int round = (int) Math.round(Math.random() * 3);
        if (round == 0) {
            this.result = yy + xx;
            number.append(yy);
            number.append("+");
            number.append(xx);
        } else if (round == 1) {
            this.result = yy - xx;
            number.append(yy);
            number.append("-");
            number.append(xx);
        } else if (round == 2) {
            this.result = yy * xx;
            number.append(yy);
            number.append("*");
            number.append(xx);
        } else {
            // 0不可为被除数 yy对xx取余无余数
            if (!(xx == 0) && yy % xx == 0) {
                this.result = yy / xx;
                number.append(yy);
                number.append("/");
                number.append(xx);
            } else {
                this.result = yy + xx;
                number.append(yy);
                number.append("+");
                number.append(xx);
            }
        }
        this.content = number.toString();
        log.info("数字计算公式 {}", this.content);
    }

    private void drawString(Graphics2D g2d, String s, int i) {
        g2d.setFont(new Font("黑体", Font.BOLD, FONT_SIZE));
        int r = RANDOM.nextInt(255);
        int g = RANDOM.nextInt(255);
        int b = RANDOM.nextInt(255);
        g2d.setColor(new Color(r, g, b));
        int x = RANDOM.nextInt(3);
        int y = RANDOM.nextInt(2);
        g2d.translate(x, y);
        int angle = new Random().nextInt() % 15;
        g2d.rotate(angle * Math.PI / 180, 5 + i * 25, 20);
        g2d.drawString(s, 5 + i * 25, 30);
        g2d.rotate(-angle * Math.PI / 180, 5 + i * 25, 20);
    }

    // 获取随机颜色
    private Color color() {
        int r = RANDOM.nextInt(256);
        int g = RANDOM.nextInt(256);
        int b = RANDOM.nextInt(256);
        return new Color(r, g, b);
    }

    public String content() {
        return content;
    }

    public int result() {
        return result;
    }
}

数字算法

此代码使用了ttf字体 字体在此处 https://gitee.com/tothis/java-record/tree/master/src/main/resources/font

package com.example.captcha;

import lombok.SneakyThrows;

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

/**
 * @author 李磊
 * @datetime 2020/7/9 20:16
 * @description
 */
public class NumberCaptcha {
    // 宽度
    private static final int IMAGE_WIDTH = 160;
    // 高度
    private static final int IMAGE_HEIGHT = 40;
    // 字体大小
    private static final int FONT_SIZE = 28;
    // 字体目录
    private static final String FONT_PATH = "/font/";
    // 字体列表
    private static final String[] FONT_NAMES = {
            "actionj.ttf", "epilog.ttf", "headache.ttf"
            , "lexo.ttf", "prefix.ttf", "robot.ttf"
    };

    private static final Random RANDOM = new Random();
    // 计算公式
    private String content;
    // 计算结果
    private int result;

    /**
     * 生成随机验证码
     */
    private void createMathChar() {
        StringBuilder number = new StringBuilder();
        int xx = RANDOM.nextInt(10);
        int yy = RANDOM.nextInt(10);
        // 0~3 对应加减乘除
        int round = (int) Math.round(Math.random() * 3);
        if (round == 0) {
            this.result = yy + xx;
            number.append(yy);
            number.append("+");
            number.append(xx);
        } else if (round == 1) {
            this.result = yy - xx;
            number.append(yy);
            number.append("-");
            number.append(xx);
        } else if (round == 2) {
            this.result = yy * xx;
            number.append(yy);
            number.append("x");
            number.append(xx);
        } else {
            // 0不可为被除数 yy对xx取余无余数
            if (!(xx == 0) && yy % xx == 0) {
                this.result = yy / xx;
                number.append(yy);
                number.append("/");
                number.append(xx);
            } else {
                this.result = yy + xx;
                number.append(yy);
                number.append("+");
                number.append(xx);
            }
        }

        content = number.append("=?").toString();
    }

    // 获取随机颜色
    private Color color() {
        int r = RANDOM.nextInt(256);
        int g = RANDOM.nextInt(256);
        int b = RANDOM.nextInt(256);
        return new Color(r, g, b);
    }

    /**
     * 随机画干扰圆
     *
     * @param num 数量
     * @param g   Graphics2D
     */
    private void drawOval(int num, Graphics2D g) {
        for (int i = 0; i < num; i++) {
            g.setColor(color());
            int j = 5 + RANDOM.nextInt(10);
            g.drawOval(RANDOM.nextInt(IMAGE_WIDTH - 25), RANDOM.nextInt(IMAGE_HEIGHT - 15), j, j);
        }
    }

    @SneakyThrows
    private Font font() {
        int index = RANDOM.nextInt(FONT_NAMES.length);
        Font font = Font.createFont(Font.TRUETYPE_FONT
                , getClass().getResourceAsStream(FONT_PATH + FONT_NAMES[index]))
                .deriveFont(Font.BOLD, FONT_SIZE);
        return font;
    }

    /**
     * 生成验证码图形
     */
    public BufferedImage create() {
        createMathChar();
        char[] chars = content.toCharArray();
        BufferedImage image = new BufferedImage(IMAGE_WIDTH, IMAGE_HEIGHT, BufferedImage.TYPE_INT_RGB);
        Graphics2D g2d = (Graphics2D) image.getGraphics();
        // 填充背景
        g2d.setColor(Color.WHITE);
        g2d.fillRect(0, 0, IMAGE_WIDTH, IMAGE_HEIGHT);
        // 抗锯齿
        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
        // 画干扰圆
        drawOval(2, g2d);
        // 画字符串
        g2d.setFont(font());
        FontMetrics fontMetrics = g2d.getFontMetrics();
        // 每一个字符所占的宽度
        int fx = IMAGE_WIDTH / chars.length;
        // 字符左填充
        int flp = 10;
        for (int i = 0; i < chars.length; i++) {
            String item = String.valueOf(chars[i]);
            g2d.setColor(color());
            // 文字的纵坐标
            int fy = IMAGE_HEIGHT - ((IMAGE_HEIGHT - (int) fontMetrics
                    .getStringBounds(item, g2d).getHeight()) >> 1);
            g2d.drawString(item, flp + i * fx + 3, fy - 3);
        }
        g2d.dispose();
        return image;
    }

    public String content() {
        return content;
    }

    public int result() {
        return result;
    }
}

测试类

package com.example.captcha;

import com.greenpineyu.fel.FelEngine;
import com.greenpineyu.fel.FelEngineImpl;
import lombok.SneakyThrows;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.File;

/**
 * @author 李磊
 * @datetime 2020/7/9 20:10
 * @description
 */
public class Main {
    @SneakyThrows
    public static void main(String[] args) {
        // 图片类型
        String IMAGE_TYPE = "png";
        ChineseCaptcha chinese = new ChineseCaptcha();
        NumberCaptcha number = new NumberCaptcha();

        for (int i = 0; i < 10; i++) {
            BufferedImage image1 = chinese.create();
            // 输出文件
            ImageIO.write(image1, IMAGE_TYPE, new File("D:/data/a" + i + ".png"));
            System.out.println(chinese.content() + ' ' + chinese.result());

            BufferedImage image2 = number.create();
            // 输出文件
            ImageIO.write(image2, IMAGE_TYPE, new File("D:/data/b" + i + ".png"));
            System.out.println(number.content() + ' ' + number.result());
        }
    }
}

---

如需要多级运算如1+2-3*4/5 则需要使用表达式引擎计算 如下为使用fel计算表达式

// fel计算表达式
FelEngine fel = new FelEngineImpl();
System.out.println(3 * 2 + 1);
System.out.println(fel.eval("3*2+1"));
System.out.println(3 * (2 + 1));
System.out.println(fel.eval("3*(2+1)"));

本文地址：https://blog.csdn.net/setlilei/article/details/107290409