Seesion的简单使用

1.Session常用方法

方法	功能
HttpSession session = request.getSession();	获取Session
Object getAttribute(String name)	获取Session属性
void setAttribute(String name, Object value)	设置Session属性
void removeAttribute(String name)	移除Session属性

2.简单的应用

2.1存值

package com.czn;

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("/session02")
public class Session02 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        HttpSession session = request.getSession();

        Object username = session.setAttribute("username");

        System.out.println(username);
    }

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

2.2取值

package com.czn;

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("/secondSession")
public class secondSession extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    public secondSession() {
        super();
    }

	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		
		//获取Session
		HttpSession session = request.getSession();
		
		//获取username的值
		Object username = session.getAttribute("username");
		
		//输出
		System.out.println(username);
	}

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

}

2.3启动tomcat

浏览器访问session01存值

浏览器访问session02取值

当回车时打印了张三,取值成功了