package com.jiudian.manage.until;

import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Random;

public class ImageCode {
    public static final String CODENAME="ImageCode";
    public static void createImage(HttpServletResponse response, HttpSession session) throws IOException {
        BufferedImage image = new BufferedImage(80, 30, BufferedImage.TYPE_INT_RGB);
        Graphics g = image.getGraphics();
        Random r = new Random();
        g.setColor(new Color(r.nextInt(255), r.nextInt(255), r.nextInt(255)));
        g.fillRect(0, 0, 80, 20);
        //获取生成的验证码
        String code = getNumber();
        //绑定验证码
        session.setAttribute(CODENAME, code);
        g.setFont(new Font(Font.SANS_SERIF, Font.BOLD, 25));
        g.setColor(new Color(r.nextInt(255), r.nextInt(255), r.nextInt(255)));
        g.drawString(code, 5, 25);
        //设置消息头
        response.setContentType("image/jpeg");
        OutputStream os = response.getOutputStream();
        ImageIO.write(image, "jpeg", os);
    }
    public static String getNumber(){
        String str = "1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ";
        String code = "";
        for(int i= 0;i<4;i++){
            int index = (int)(Math.random()*str.length());
            code+=str.charAt(index);
        }
        return code;
    }
}