Cookies and sessions

Cookie
Cookie Is a session management technology , It is used to save the data generated during the session , Then when the browser interacts with the server ,
Will use cookie The data stored in it .

After starting

Session object
session Is a session management technology ,session Used to save data during the session , The saved data is stored on the server side .
session Common methods ：
1. obtain session Of id(JESSIONID Corresponding value )： getId();
2. Set up session Life span of ：setMaxInactiveInterval(int interval)
3. The destruction session: invalidate();
obtain session: HttpSession session = getSession();

session Domain object ： Scope a full session （ Contains multiple requests ）
1. Store value ： setAttribute(String key,Object obj);
2. Value ： Object obj =getAttribute(String key);
3. remove ： removeAttribute(String key);