2020.04.20 简易验证码生成练习

package com.aojie.web.servlet;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

/**
 * @author aojie
 * @fuction 重定向
 * @create 2020-04-19 21:26
 */
    @WebServlet("/checkcodeservlet")
public class CheckCodeServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        /*
        1.创建对象，在内存中生成图片（验证码图片对象）
        2.美化图片
            填充背景色
        3.将图片输出到页面展示
         */
        int width=100;
        int height=50;
        BufferedImage image=new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
        //设置画笔
        Graphics graphics = image.getGraphics();
        //设置画笔颜色
        graphics.setColor(Color.pink);
        //0,0代表起始坐标
        graphics.fillRect(0,0,width,height);
        //画边框
        graphics.setColor(Color.blue);
        graphics.drawRect(0,0,width-1,height-1);
        //写验证码
        String str="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789";
        Random random=new Random();
        for (int i = 1; i <= 4  ; i++) {
            int ran = random.nextInt(str.length());
            char c = str.charAt(ran);
            graphics.drawString(c+"",width/5*i,25);
        }
        //画干扰线
        graphics.setColor(Color.green);
        for (int i = 0; i < 10; i++) {
            int x1 = random.nextInt(width);
            int x2 = random.nextInt(width);
            int y1 = random.nextInt(height);
            int y2 = random.nextInt(height);
            graphics.drawLine(x1,y1,x2,y2);
        }

        ImageIO.write(image,"jpg",response.getOutputStream());
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request,response);
    }
}