package com.lsgjzhuwei.servlet.response;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

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;

/**
 * Servlet implementation class VerificationCode
 */
@WebServlet(asyncSupported = true, urlPatterns = { "/VerificationCode" })
public class VerificationCode extends HttpServlet {
 private static final long serialVersionUID = 1L;
    
  /**
   * @see HttpServlet#HttpServlet()
   */
  public VerificationCode() {
    super();
    // TODO Auto-generated constructor stub
  }

 /**
  * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
  */
 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  // TODO Auto-generated method stub
  
  int width = 120;
  int height = 30;
  
  //创建一张内存中的缓存图片
  BufferedImage bufferedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
  
  ///背景色
  //通过graphics绘制图像
  Graphics graphics = bufferedImage.getGraphics();
  //设置颜色
  graphics.setColor(Color.yellow);
  //填充
  graphics.fillRect(0, 0, width, height);
  
  ///画边框
  graphics.setColor(Color.blue);
  graphics.drawRect(0, 0, width-1, height-1);
  
  //写字母
  String content = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcedfghijklmnopqrstuvwxyz1234567890";
  Random random = new Random();
  //设置字体颜色
  graphics.setColor(Color.red);
  //设置字体及大小
  graphics.setFont(new Font("宋体", Font.BOLD, 20));
  int x=20;
  int y=20;
  for(int i = 0; i < 4; i++)
  {
   int index = random.nextInt(content.length());
   char letter = content.charAt(index);
   graphics.drawString(letter+" ", x, y);
   x = x+20;
  }
  
  //绘制干扰线
  int x1;
  int x2;
  int y1;
  int y2;
  graphics.setColor(Color.LIGHT_GRAY);
  for(int i = 0;i <50;i++)
  {
   x1=random.nextInt(width);
   x2=random.nextInt(width);
   y1=random.nextInt(height);
   y2=random.nextInt(height);
   graphics.drawLine(x1, y1, x2, y2);
  }
  
  //将图片输出到浏览器
  //将内存的图片通过浏览器输出流输出成jpg图片
  ImageIO.write(bufferedImage, "jpg", response.getOutputStream());
  
  
 }

 /**
  * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
  */
 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  // TODO Auto-generated method stub
 }

}