com.pongsky.kit.captcha.utils.KaptchaUtils Maven / Gradle / Ivy
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package com.pongsky.kit.captcha.utils;
import com.pongsky.kit.captcha.enums.MathType;
import org.apache.commons.lang3.RandomUtils;
import org.apache.commons.lang3.math.NumberUtils;
import javax.imageio.ImageIO;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.text.MessageFormat;
import java.util.Base64;
import java.util.Random;
/**
* 输入型算数 验证码工具类
*
* @author pengsenhao
*/
public class KaptchaUtils {
/**
* 最小验证码数值
*
* 最小 10
*/
private final int minCode;
/**
* 最大验证码数值
*/
private final int maxCode;
/**
* 图像宽度
*/
private final int imageWidth;
/**
* 图像高度
*/
private final int imageHeight;
/**
* 干扰线数量
*/
private final int drawCount;
/**
* 干扰线的长度 = 1.414 * LINE_WIDTH
*/
private final int lineWidth;
public KaptchaUtils(int minCode, int maxCode,
int imageWidth, int imageHeight,
int drawCount, int lineWidth) {
this.minCode = minCode;
this.maxCode = maxCode;
this.imageWidth = imageWidth;
this.imageHeight = imageHeight;
this.drawCount = drawCount;
this.lineWidth = lineWidth;
}
/**
* 创建图像验证码
*
* @param code 验证码
* @return 创建图像验证码
*/
private BufferedImage createImage(int code) {
String codeText = this.createCode(code);
// 在内存中创建图像
final BufferedImage image = new BufferedImage(imageWidth, imageHeight, BufferedImage.TYPE_INT_RGB);
// 获取图形上下文
final Graphics2D graphics = (Graphics2D) image.getGraphics();
// 设定背景颜色
graphics.setColor(Color.WHITE);
graphics.fillRect(0, 0, imageWidth, imageHeight);
graphics.drawRect(0, 0, imageWidth - 1, imageHeight - 1);
final Random random = new Random();
// 随机产生干扰线，使图像中的认证码不易被其它程序探测到
for (int i = 0; i < drawCount; i++) {
graphics.setColor(getRandColor(150, 200));
// 保证画在边框之内
final int x = random.nextInt(imageWidth - lineWidth - 1) + 1;
final int y = random.nextInt(imageHeight - lineWidth - 1) + 1;
final int xl = random.nextInt(lineWidth);
final int yl = random.nextInt(lineWidth);
graphics.drawLine(x, y, x + xl, y + yl);
}
// 取随机产生的认证码
int x = 0;
for (int i = 0; i < codeText.length(); i++) {
// 将认证码显示到图像中,调用函数出来的颜色相同，可能是因为种子太接近，所以只能直接生成
// 设置字体颜色
graphics.setColor(Color.BLACK);
// 设置字体样式
graphics.setFont(new Font("Times New Roman", Font.BOLD, 24));
// 设置字符，字符间距，上边距
String str = String.valueOf(codeText.charAt(i));
if (NumberUtils.isCreatable(str)) {
// 数字与数字之间间隔小点
x += 6 + 8;
} else {
// 遇到符号则间隔大点
// FORMAT 中间有空格，所以这边的 x 轴增加较小
x += 4 + 4;
}
graphics.drawString(str, x, 26);
}
// 图像生效
graphics.dispose();
return image;
}
/**
* 验证码格式
*/
private static final String CODE_FORMAT = "{0} {1} {2} = ?";
/**
* 最大数值
*/
private static final int MAX_NUM = 100;
/**
* 获取验证码文本
*
* @param code 验证码
* @return 获取验证码文本
*/
private String createCode(int code) {
int num = RandomUtils.nextInt(1, 9);
MathType mathType = MathType.ALL.get(new Random().nextInt(MathType.ALL.size()));
switch (mathType) {
case ADD:
return MessageFormat.format(CODE_FORMAT,
code - num,
mathType.getCode(), num);
case SUBTRACT:
return MessageFormat.format(CODE_FORMAT,
code + num,
mathType.getCode(), num);
case MULTIPLY:
if (code % num > 0) {
num = code;
}
return MessageFormat.format(CODE_FORMAT,
code / num,
mathType.getCode(), num);
case DIVIDE:
if (code * num > MAX_NUM) {
// 数字太大的话，不好口算，用户体验会很差
num = 1;
}
return MessageFormat.format(CODE_FORMAT,
code * num,
mathType.getCode(), num);
default:
return "";
}
}
/**
* 最大颜色数
*/
private static final int MAX_COLOR_NUM = 255;
/**
* 取得给定范围随机颜色
*
* @param fc fc
* @param bc bc
* @return 颜色
*/
private Color getRandColor(int fc, int bc) {
final Random random = new Random();
if (fc > MAX_COLOR_NUM) {
fc = MAX_COLOR_NUM;
}
if (bc > MAX_COLOR_NUM) {
bc = MAX_COLOR_NUM;
}
final int r = fc + random.nextInt(bc - fc);
final int g = fc + random.nextInt(bc - fc);
final int b = fc + random.nextInt(bc - fc);
return new Color(r, g, b);
}
/**
* 创建验证码
*
* @return 创建验证码
*/
public int createCode() {
return RandomUtils.nextInt(minCode, maxCode);
}
/**
* 图片格式类型
*/
private static final String FORMAT_NAME = "jpg";
/**
* 创建图像验证码 Stream 流
*
* @param code 验证码
* @return 创建验证码 Stream 流
* @throws IOException IOException
*/
public ByteArrayOutputStream createImageByStream(int code) throws IOException {
BufferedImage image = this.createImage(code);
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
try {
ImageIO.write(image, FORMAT_NAME, outputStream);
} finally {
if (outputStream != null) {
outputStream.close();
}
}
return outputStream;
}
/**
* 创建图像验证码，并写入 Stream 流
*
* @param code 验证码
* @param outputStream outputStream
* @throws IOException IOException
*/
public void createImageByStream(int code, OutputStream outputStream) throws IOException {
BufferedImage image = this.createImage(code);
try {
ImageIO.write(image, FORMAT_NAME, outputStream);
} finally {
if (outputStream != null) {
outputStream.close();
}
}
}
/**
* 创建图像验证码 Base64 信息
*
* @param code 验证码
* @return 创建验证码 Base64 信息
* @throws IOException IOException
*/
public String createImageByBase64(int code) throws IOException {
ByteArrayOutputStream outputStream = this.createImageByStream(code);
return Base64.getEncoder().encodeToString(outputStream.toByteArray());
}
}