Cookie會話技術——快速入門

目錄

Cookie：

 1.概念：客戶端會話數據技術，將數據保存到客戶端。

  2.快速入門：

3.實現原理：

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Cookie：

 1.概念：客戶端會話數據技術，將數據保存到客戶端。

 

  2.快速入門：

 使用步驟:

        ①創建Cookie對象，綁定數據

        new Cookie(String name,String value)

        ②發送Cookie對象

        response.addCookie(Cookie cookie)

        ③獲取Cookie，拿到數據

        Cookie[] request.getCookies()

 

CookieDemo1類：

package jason.lh.cookie;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;


//Cookie快速入門

@WebServlet("/CookieDemo1")
public class CookieDemo1 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

         //①創建Cookie對象
        Cookie c = new Cookie("msg","Hello");
        //②發送Cookie
        response.addCookie(c);
        //

    }

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

CookieDemo2類：

package jason.lh.cookie;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;


//Cookie快速入門

@WebServlet("/CookieDemo2")
public class CookieDemo2 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //③獲取Cookie
        Cookie[] cs = request.getCookies();
        //④獲取數據，遍歷Cookies
        if (cs != null) {
            for (Cookie c : cs) {
                String name = c.getName();
                String value = c.getValue();
                System.out.println(name + ":" + value);
            }

        }
    }

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

}

虛擬目錄位/day16

控制檯輸出：

 

3.實現原理：

基於響應set-cookie和請求頭cookie實現