会话技术Session快速入门和Session原理分析

Session

• 概念：服务器端会话技术，再一次会话的多次请求间共享数据，将数据保存再服务器端的对象中。HTTPSession
• 快速入门：
  • 获取HttpSession对象
    • HttpSession session = request.getSession();
  • 使用HttpSession对象：
    • Object getAttribute(String name)
    • void setAttribute(String name,Object value)
    • void removeAttribute(String name)

package com.ailyt.session;

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

@WebServlet(value = "/sessionStudy01")
public class SessionStudy01 extends HttpServlet {
    @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("html/text;charset=utf-8");
        //使用Session共享数据
        //1.获取Session
        HttpSession session = request.getSession();
        //2.存储数据
        session.setAttribute("msg","hello session");
    }
}

package com.ailyt.session;

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

@WebServlet(value = "/sessionStudy02")
public class SessionStudy02 extends HttpServlet {
    @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 {
        //使用Session获取数据

        //获取Session
        HttpSession session = request.getSession();
        //获取数据
        Object value1 = session.getAttribute("msg");
        System.out.println("-->" + value1);
    }
}

Session原理分析

• Session的实现是依赖于Cookie的