package com.util;



import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.util.Random;
/**
 *  图片验证码工具类
 * @ignore
 * @Author:Alcedo QQ:815657032
 * @Date 2023/3/15 11:05
 */
public class ImgCodeUtil {
	private BufferedImage image;// 图像
	private String str;// 验证码
	private static char code[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ123456789".toCharArray();
	public static final String SESSION_CODE_NAME="code";
	private ImgCodeUtil() {
		init();// 初始化属性
	}

	/*
	 * 取得RandomNumUtil实例
	 */
	public static ImgCodeUtil Instance() {
		return new ImgCodeUtil();
	}

	/*
	 * 取得验证码图片
	 */
	public BufferedImage getImage() {
		return this.image;
	}

	/*
	 * 取得图片的验证码
	 */
	public String getString() {
		return this.str;
	}

	private void init() {
		// 在内存中创建图象
		int width = 85, height = 20;
		BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
		// 获取图形上下文
		Graphics g = image.getGraphics();
		// 生成随机类
		Random random = new Random();
		// 设定背景色
		g.setColor(getRandColor(200, 250));
		g.fillRect(0, 0, width, height);
		// 设定字体
		g.setFont(new Font("Times New Roman", Font.PLAIN, 18));
		// 随机产生155条干扰线，使图象中的认证码不易被其它程序探测到
		g.setColor(getRandColor(160, 200));
		for (int i = 0; i < 155; i++) {
			int x = random.nextInt(width);
			int y = random.nextInt(height);
			int xl = random.nextInt(12);
			int yl = random.nextInt(12);
			g.drawLine(x, y, x + xl, y + yl);
		}
		// 取随机产生的认证码(4位数字)
		String sRand = "";
		for (int i = 0; i < 4; i++) {
			String rand = String.valueOf(code[random.nextInt(code.length)]);
			sRand += rand;
			// 将认证码显示到图象中
			g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
			// 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
			g.drawString(rand, 13 * i + 6, 16);
		}
		// 赋值验证码
		this.str = sRand;

		// 图象生效
		g.dispose();
		this.image = image;/* 赋值图像 */
	}

	/*
	 * 给定范围获得随机颜色
	 */
	private Color getRandColor(int fc, int bc) {
		Random random = new Random();
		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);
	}



}

