com.synnex.saas.platform.core.servlet.CaptchaServlet.java Source code

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Here is the source code for com.synnex.saas.platform.core.servlet.CaptchaServlet.java

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/******************************************************************************
 * @Copyright Notice: 
 * Copyright (c) 2012 SYNNEX Corporation. All  Rights Reserved.
 * This software is published under the terms of the SYNNEX Software
 * License version 1.0, a copy of which has been included with this
 * distribution in the LICENSE.txt file.
 * 
 *****************************************************************************/
package com.synnex.saas.platform.core.servlet;

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.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.apache.commons.lang.RandomStringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 
 * @author stevenl
 * @datetime 2015-3-3 ?1:39:05
 */
public class CaptchaServlet extends HttpServlet {

    private static final long serialVersionUID = -5002751698069912752L;
    private static Logger logger = LoggerFactory.getLogger(CaptchaServlet.class);

    public CaptchaServlet() {
        super();
    }

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

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        try {
            int width = 50;
            int height = 18;
            String captchaCode = RandomStringUtils.random(4, true, true);
            HttpSession session = request.getSession(true);
            session.setAttribute("captchaCode", captchaCode);

            response.setContentType("images/jpeg");
            response.setHeader("Pragma", "No-cache");
            response.setHeader("Cache-Control", "no-cache");
            response.setDateHeader("Expires", 0);

            ServletOutputStream out = response.getOutputStream();
            BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
            Graphics g = image.getGraphics();
            g.setColor(getRandColor(200, 250));
            g.fillRect(0, 0, width, height);
            Font mFont = new Font("Times New Roman", Font.BOLD, 18);
            g.setFont(mFont);
            g.setColor(getRandColor(160, 200));
            Random random = new Random();
            for (int i = 0; i < 155; i++) {
                int x2 = random.nextInt(width);
                int y2 = random.nextInt(height);
                int x3 = random.nextInt(12);
                int y3 = random.nextInt(12);
                g.drawLine(x2, y2, x2 + x3, y2 + y3);
            }
            g.setColor(new Color(20 + random.nextInt(110), 20 + random.nextInt(110), 20 + random.nextInt(110)));
            g.drawString(captchaCode, 2, 16);
            g.dispose();
            ImageIO.write((BufferedImage) image, "JPEG", out);
            out.close();
        } catch (Exception e) {
            logger.error("Generate captcha failed.", e);
        }
    }

    private Color getRandColor(int fc, int bc) {
        Random random = new Random();
        if (fc > 255) {
            fc = 255;
        }
        if (bc > 255) {
            bc = 255;
        }
        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);
    }

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

    public void init() throws ServletException {

    }

}