package my.utils;

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.ServletOutputStream;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class GenerateVcodeServlet
 * @author
 */
@WebServlet("/GenerateVcodeServlet")
public class GenerateVcodeServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;

	private static int m155 =155;

	private static int m6 =6;

	private static int m255 =255;

	public GenerateVcodeServlet() {
	}

	@Override
	protected void doGet(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		resp.setContentType("image/jpeg");
		resp.setHeader("Pragma", "No-cache");
		resp.setHeader("Cache-Control", "No-cache");
		resp.setDateHeader("Expires", 0L);
		int width = 85;
		int height = 20;
		BufferedImage image = new BufferedImage(width, height, 1);
		Graphics g = image.getGraphics();
		Random random = new Random();
		g.setColor(getRandColor(200, 250));
		g.fillRect(0, 0, width, height);
		g.setFont(new Font("Times New Roman", 0, 18));
		g.setColor(getRandColor(160, 200));
		for (int i = 0; i < m155; 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);
		}

		String sRand = "";
		for (int i = 0; i < m6; i++) {
			String rand = String.valueOf(random.nextInt(10));
			sRand = (new StringBuilder(String.valueOf(sRand))).append(rand)
					.toString();
			g.setColor(new Color(20 + random.nextInt(110), 20 + random
					.nextInt(110), 20 + random.nextInt(110)));
			g.drawString(rand, 13 * i + 6, 16);
		}

		req.getSession(true).setAttribute("vcode", sRand);
		g.dispose();
		ServletOutputStream out = resp.getOutputStream();
		ImageIO.write(image, "JPEG", out);
		out.flush();
	}

	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws ServletException, IOException {
		doGet(req, resp);
	}

	private Color getRandColor(int fc, int bc) {
		Random random = new Random();
		if (fc > m255) {
			fc = m255;
		}
		if (bc > m255) {
			bc = m255;
		}
		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);
	}

}