关于symfony的session和cookie

Symfony HttpFoundation component provides cookie and session management in an object-oriented manner. 
Cookie provides client-side data storage and it only supports a small amount of data. Usually, 
it is 2KB per domain and it depends on the browser. 
Session provides server-side data storage and it supports a large amount of data. 
Let us see how to create a cookie and session in a Symfony web application.  

Cookie
Symfony provides Cookie class to create a cookie item. Let us create a cookie color, which expires in 24 hours with value blue. The constructor parameter of the cookie class is as follows.

name (type: string) - cookie name
value (type: string) - cookie value
expire (type: integer / string / datetime) - expiry information
path (type: string) - the server path in which the cookie is available
domain (type: string) – the domain address in which the cookie is available
secure (type: boolean) - whether the cookie needs to be transmitted in HTTPS connection
httpOnly (type: boolean) - whether the cookie is available only in HTTP protocol

ex:
use Symfony\Component\HttpFoundation\Cookie;  
$cookie = new Cookie('color', 'green', strtotime('tomorrow'), '/', 
   'somedomain.com', true, true);


Now, the created cookie needs to be attached to the http response object's header as follows.
$response->headers->setCookie($cookie);

To get the cookie, we can use Request object as follows
$cookie = $request->cookie->get('color'); 


Session
Symfony provides a Session class implementing SessionInterface interface. The important session API are as follows,

start − Starts the session.

Session $session = new Session(); 
$session->start(); 
invalidate − Clears all session data and regenerates the session ID.

set − Stores data in the session using a key.

$session->set('key', 'value');
We can use any data in the session value, be in simple integer to complex objects.

get − Gets data from the session using the key.

$val = $session->get('key');
remove − Removes a key from the session.

clear − Removes a session data.