Cookie的存活时间

import javax.servlet.http.Cookie;
//--------省略若干代码-----------
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//1.创建Cookie对象，绑定数据【name是"msg"，value是"hello"】
Cookie c = new Cookie("msg", "hello");
//2.设置Cookie存活时间
c.setMaxAge(300);//(1).将Cookie持久化到硬盘，300秒后会自动删除
//c.setMaxAge(-1);//(2).默认值，一次浏览器会话
//c.setMaxAge(0);//(3).删除Cookie
//3.发送Cookie对象【只有发送Cookie的浏览器可以获取Cookie】
response.addCookie(c);
}
//--------省略若干代码-----------

import javax.servlet.http.Cookie;
//--------省略若干代码-----------
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//3.获取Cookie
Cookie[] cs = request.getCookies();
//4.遍历Cookies
if(cs!=null){
for(Cookie c:cs){
String name = c.getName();
String value = c.getValue();
System.out.println(name+":"+value);
}
}
}
//--------省略若干代码-----------