What is Session?
A session management server object exists (tomcat as an example) of
What is a Cookie?
Browser presence of a small text file (to save related data)
What is SessionId?
Used to obtain a sequence number of the Session answer (JVM + + actual value of the random id) id derived from the JVM's information calculation hardware
Session is created when?
HttpSession session = requset.getSession (); Create obtained, while () obtained by session.getId SessionIdSession and Cookie role?
Are used to save data of the user, has validity, it can be saved to a file by means of the corresponding
(Cookie in the use of the process is in memory, close the browser will disappear) unless the dump file
(Session presence server in a certain storage time)
The use of flow between the actual development
First, the browser requests the server, is generated by the session object on the server Request.getSession ()
HttpSession session =requset.getSession();
Second, obtaining the session object generated by sessionId
String sessionId = session.getId()
Third, the sessionId returned to the browser, the cookie deposited into
- Get cookie
Cookie[] cookies = request.getCookies();
- Of cookie operation (add, delete, change, check, deposit)
- Returned to the browser
response.addCookie(cookie);
Cookie related operations
Create a way to get the cookie object: Cookie cookie = new Cookie (name, value);
Cookie object has been acquired manner: Cookie [] cookies = req.getCookies ();
Cookie object data operations:
1. Get Name: the Cookie.getName ()
2, to obtain the value: cookie.getValue ()
. 3, set the name: cookie.setName ()
. 4, the set value: cookie.setValue ()Cookie, for example, residence time is provided: cookie.setMaxAge (365 * 24 * 60 * 60); in seconds
Save Cookie object to the browser: response.addCookie (cookie);
Set Cookie storage path: cookie2.setPath ( "/");
Data Update Session in
session.setAttribute save (the default method will save)
session.getAttribute get