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package org.servlet.sessionMngmt;

import java.io.IOException;

import java.io.PrintWriter;

import javax.servlet.ServletException;

import javax.servlet.annotation.WebServlet;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import javax.servlet.http.HttpSession;

/*

 * Copyright [2015] [Jeff Lee]

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *   http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

/**

 * @author Jeff Lee

 * @since 2015-7-12 10:58:28

 *  HttpSession的默认Cookie实现案例

 */

@WebServlet(urlPatterns = "/sessionByCookie")

public class HttpSessionByCookieServletT extends HttpServlet {

    private static final long serialVersionUID = 1L;

    @Override

    protected void doGet(HttpServletRequest req, HttpServletResponse resp)

            throws ServletException, IOException {

        // 获取session

        // 如果是第一次请求的话，会创建一个HttpSeesion，等同于 req.getSession(true);

        // 如果已存在session，则会获取session。

        HttpSession session = req.getSession();

        if (session.isNew()) {

            // 设置session属性值

            session.setAttribute("name", "Jeff");

        }

        // 获取SessionId

        String sessionId = session.getId();

        PrintWriter out = resp.getWriter();

        // 如果HttpSeesion是新建的话

        if (session.isNew()) {

            out.println("Hello,HttpSession! <br>The first response - SeesionId="

                    + sessionId + " <br>");

        } else {

            out.println("Hello,HttpSession! <br>The second response - SeesionId="

                    + sessionId + " <br>");

            // 从Session获取属性值

            out.println("The second-response - name: "

                    + session.getAttribute("name"));

        }

    }

}