servlet Cookie使用方法详解（六）

本文实例为大家分享了servlet cookie的使用方法，供大家参考，具体内容如下

1.cookie介绍

　　cookie，指某些网站为了辨别用户身份、进行 session 跟踪而储存在用户本地终端上的数据（通常经过加密）。（可以叫做浏览器缓存）

2.cookie案例

servlet 源码

package com.learn;

import javax.servlet.servletexception;
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.io.printwriter;

/**
 * 
 */
public class cookieservlet extends httpservlet {

 @override
 protected void doget(httpservletrequest req, httpservletresponse resp) throws servletexception, ioexception {
  //cookie引用
  cookie cookie = null;
  //设置返回类型为文本类型
  resp.setcontenttype("text/plain");
  //获取输出对象
  printwriter out = resp.getwriter();

  //从请求参数中获取cookies
  cookie[] cookies = req.getcookies();
  if(cookies != null){
   for (int i = 0; i < cookies.length ; i++) {
    out.println("name:"+cookies[i].getname());
    out.println("value:"+cookies[i].getvalue());
    //如果cookie值为user，则赋值给cookie
    if(cookies[i].getname().equals("user")){
     cookie = cookies[i];
    }
   }

  } else {
   out.print("no cookie");
  }

  if(cookie == null){
   cookie = new cookie("user","tom");
   //设置cookie最大值为60分钟
   cookie.setmaxage(60*60);
   resp.addcookie(cookie);
  } else if(cookie.getvalue().equals("tom")){
   cookie.setvalue("jack");
   resp.addcookie(cookie);
  } else if(cookie.getvalue().equals("jack")){
   cookie.setmaxage(0);
   resp.addcookie(cookie);
  }

  out.close();
 }

 @override
 protected void dopost(httpservletrequest req, httpservletresponse resp) throws servletexception, ioexception {
  super.dopost(req, resp);
 }
}

web,xml 配置

<servlet>
  <servlet-name>cookie</servlet-name>
  <servlet-class>com.learn.cookieservlet</servlet-class>
 </servlet>
 <servlet-mapping>
  <servlet-name>cookie</servlet-name>
  <url-pattern>/cookie</url-pattern>
</servlet-mapping>

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。