Java_cookie基础

 

 

package com.xxxx.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;

@WebServlet("/c01")
public class Cookie01 extends HttpServlet {
    @Override
    protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        Cookie cookie = new Cookie("name","admin");
//        响应cookie对象
        response.addCookie(cookie);
    }
}

 

 

 

package com.xxxx.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;
//获取cookie
@WebServlet("/c02")
public class Cookie02 extends HttpServlet {
    @Override
    protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        Cookie[] cookies = request.getCookies();
//        判断coookies是否为空
        if(cookies != null && cookies.length >0){
            for (Cookie cookie:cookies) {
                String name = cookie.getName();
                String value = cookie.getValue();
                System.out.println("mingcheng：" + name  + ",zhi："+ value);
            }

        }

    }
}

 

 

package com.xxxx.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;

//获取cookie
@WebServlet("/c03")
public class Cookie03 extends HttpServlet {
    @Override
    protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
/*到期时间：负整数*/
        Cookie cookie1 = new Cookie("name1", "value1");
        cookie1.setMaxAge(-1);
        response.addCookie(cookie1);
        /*到期时间：正整数*/
        Cookie cookie2 = new Cookie("name2", "value2");
        cookie2.setMaxAge(20);
        response.addCookie(cookie2);
        /*到期时间：0*/
        Cookie cookie3 = new Cookie("name3", "value3");
        cookie3.setMaxAge(0);
        response.addCookie(cookie3);

    }
}

 

 

package com.xxxx.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;
import java.net.URLDecoder;
import java.net.URLEncoder;

//获取cookie
@WebServlet("/c04")
public class Cookie04 extends HttpServlet {
    @Override
    protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        String name = "姓名";
        String value = "张三";

//        将中文通过URLEncode进行编码
        name = URLEncoder.encode(name);
        value = URLEncoder.encode(value);

        Cookie cookie = new Cookie(name, value);
        response.addCookie(cookie);

//        将中文通过URLDecoder进行解码
        Cookie[] cookies = request.getCookies();
//        判断非空
        if(cookies != null && cookies.length >0){

            for (Cookie c:cookies ) {

                System.out.println(URLDecoder.decode(c.getName()));
                System.out.println(URLDecoder.decode(c.getValue()));
            }
        }



    }
}

 

 

package com.xxxx.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;
import java.net.URLDecoder;
import java.net.URLEncoder;
//只有访问的路径中包含cookie对象的path时，此时才能获取到cookie对象
@WebServlet("/c05")
public class Cookie05 extends HttpServlet {
    @Override
    protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
//任意
        Cookie cookie1 = new Cookie("n1", "v1");
        cookie1.setPath("/");
        response.addCookie(cookie1);
//当前项目下
        Cookie cookie2 = new Cookie("n2", "v2");
        cookie2.setPath("/SS");
        response.addCookie(cookie2);
//指定项目下
        Cookie cookie3 = new Cookie("n3", "v3");
        cookie3.setPath("/S");
        response.addCookie(cookie3);
//指定目录下
        Cookie cookie4 = new Cookie("n4", "v4");
        cookie4.setPath("/SS/c02");
        response.addCookie(cookie4);


    }
}