Session Technology_Session_Quick Start

table of Contents

1. Concept:

2. Quick start:

3. The principle analysis of Session

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Session:

1. Concept:

        Server-side session technology, sharing data among multiple requests in a session, and storing the data in server-side objects. HttpSession

2. Quick start:

        ①Get the HttpSession object:

             HttpSession session = request.getSession();

        ②Using HttpSession object:

            Object getAttribute(String name)

            void setAttribute(String name,Object value)

            void removeAttribute(String name)

 

package jason.lh.session;

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;
import java.io.IOException;


@WebServlet("/SessionDemo1")
public class SessionDemo1 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            //使用session共享数据

        //①获取session
        HttpSession session = request.getSession();

        //②存储数据
       session.setAttribute("jason","hello session");

    }

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

 

package jason.lh.session;

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;
import java.io.IOException;


@WebServlet("/SessionDemo2")
public class SessionDemo2 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //使用|session获取数据

        //①获取session
        HttpSession session = request.getSession();

        //②获取数据
        Object jason = session.getAttribute("jason");
        System.out.println(jason);
    }

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

 

 

 

3. The principle analysis of Session

The realization of Session is dependent on Cookie