【转载】servlet中创建与获取session

   1.原理图(简图)

    

2.代码

  设置session

import javax.servlet.http.*;
import javax.servlet.*;
import java.io.*;

public class setSession extends HttpServlet{

 public  void doGet(HttpServletRequest req,
                     HttpServletResponse resp)
              throws ServletException,
                      IOException{
           HttpSession session=req.getSession();//返回与当前request相关联的session，如果没有则在服务器端创建一个;
           session.setAttribute("username","zhangjie");
          
                   resp.getWriter().println("------setSession() is ok--------");
          }
}

获取session：

import javax.servlet.http.*;
import javax.servlet.*;
import java.io.*;

public class getSession extends HttpServlet{

 public  void doGet(HttpServletRequest req,
                     HttpServletResponse resp)
              throws ServletException,
                      IOException{
           HttpSession session=req.getSession();//返回与当前request相关联的session，如果没有则在服务器端创建一个;
           resp.getWriter().println(session.getAttribute("username"));
          
                   resp.getWriter().println("------getSession() is ok--------");
          }
}