package com.neil.Hose.action;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Random;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ValidateCode extends HttpServlet {

	/**
	 * Destruction of the servlet. <br>
	 */
	public ValidateCode() {
		super();
	}

	public void destroy() {
		super.destroy();
	}

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

	/**
	 * 产生随机数
	 * 
	 * @param number
	 * @return
	 */
	public String randomString(int number) {
		// 生产字符的内容
		String str = "23456789qwertyuipasdfghjklzxcvbnm";
		char[] chars = str.toCharArray();
		int length = chars.length;
		StringBuilder sb = new StringBuilder();
		Random random = new Random();
		// 随机生成number个字符
		for (int i = 0; i < number; i++) {
			// 吧单个字符转换成追加到已经产生的字符串中
			sb.append(new String(new Character(chars[random.nextInt(length)])
					.toString()));
		}

		return sb.toString();
	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		// 设置响应格式
		response.setContentType("image/jpeg");
		// 定义一个BuufferedImage对象
		BufferedImage image = new BufferedImage(80, 20,
				BufferedImage.SCALE_SMOOTH);
		// 根据上述对象产生一个Graphics2D上下文
		Graphics2D graphics = image.createGraphics();
		// 将上下文颜色设置为白色
		graphics.setColor(Color.white);
		graphics.fillRect(0, 0, 100, 20);
		// 设置字体
		graphics.setFont(new Font("Roman", Font.CENTER_BASELINE, 20));
		// 产生4个字符的字符串
		String randomStr = randomString(4);
		// 生成的验证码存放到Session中
		request.getSession().setAttribute("showcode", randomStr);
		for (int i = 0; i < randomStr.length(); i++) {
			// 随机设置上下文颜色
			graphics.setColor(new Color(new Random().nextInt(250), new Random()
					.nextInt(250), new Random().nextInt(250)));
			// 按字符把其画出来
			graphics.drawString(randomStr.substring(i, i + 1), 15 * i, 16);
			// 产生干扰线
			graphics.drawLine(7, 7, 7, 7);

		}
		// 禁止缓存代码，没有这段话则不能进行更新显示
		response.setHeader("Prama", "no-cache");
		response.setHeader("Coche-Chontrol", "no-cache");
		response.setDateHeader("Expires", 0);
		// 写入客户端
		ImageIO.write(image, "jpeg", response.getOutputStream());

	}

	public void init() throws ServletException {

	}

}