IT兄弟连 JavaWeb教程 Servlet会话跟踪 经典案例

• 2019 年 10 月 5 日
• 笔记

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本文链接：https://blog.csdn.net/ITXDL123/article/details/90089770

案例需求：编写一个servlet，可以向session中存放一个消息，再编写一个servlet可以从session取得session中存放的这个消息。

案例实现：

package com.xdl.servlet;  import java.io.IOException;  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;  @WebServlet("/addSessionData.do")  public class XdlCreateSession extends HttpServlet {      private static final long serialVersionUID = 1L;      protected void service(HttpServletRequest request,                HttpServletResponse response) throws ServletException, IOException {          //如何获取session 对象          HttpSession  session  = request.getSession();          session.setAttribute("msg", "java是目前应用最广泛的语言");      }  }  package com.xdl.servlet;  import java.io.IOException;  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;  @WebServlet("/getSessionData.do")  public class GetSessionDataServlet extends HttpServlet {      private static final long serialVersionUID = 1L;      protected void service(HttpServletRequest request,                HttpServletResponse response) throws ServletException, IOException {          HttpSession  session = request.getSession();          //从session 对象中获取数据          String msg = (String)session.getAttribute("msg");          System.out.println("msg=" + msg);      }  }