lodsve.web.utils.CaptchaServlet Maven / Gradle / Ivy

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/*
 * Copyright (C) 2018  Sun.Hao
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see .
 */

package lodsve.web.utils;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.awt.image.BufferedImage;
import java.io.IOException;

/**
 * 绘制图形验证码的servlet
 *
 * @author sunhao([email protected])
 * @date 12-3-21 下午8:56
 */
public class CaptchaServlet extends HttpServlet {
    private static final long serialVersionUID = -4395293913583955749L;

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

    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("image/jpeg");
        // 设置页面不缓存
        response.setHeader("Pragma", "No-cache");
        response.setHeader("Cache-Control", "no-cache");
        response.setDateHeader("Expires", 0);

        BufferedImage image = CaptchaUtils.buildCode(4, request);

        // 输出图象到页面
        ImageIO.write(image, "JPEG", response.getOutputStream());
    }

    @Override
    public void destroy() {
    }
}