JSP (Java Server Page) JSP state management

Two mechanisms to save the state of a user (Cookie Session)

1.Cookie (Web server saves text messages on the client)

1.1 Effects:
1. Tracking for a specific object
2. Save user's web browsing history and habits
3. Simplified login operation
1.2 Disadvantages:
There is a security risk, easy to disclose user information

1.3 Creating/Using Cookies
1. Create a Cookie Object
Cookie cookie = new cookie (String key,object obj);
2. Write Cookie Object
Response.addcookie (cookie);
3. Read cookies
cookie[] cookies = request.getcookies ();

1.4 Common methods:

Method name	Describe
void setmaxage (int expiry)	Set the lifetime of the cookie, in seconds
void SetValue (String value)	After creating a cookie, assign a value to the cookie
String GetName ()	Get the name of the cookie
String GetValue ()	Get the value of a cookie
int Getmaxage ()	Gets the effective time of the cookie, in seconds

2.Session and Cookie Differences

	Session	Cookies
Describe	Saving user information on the server	Saving user information on the client
	Object type is saved in session	When a cookie is saved, string type
	Destroys data stored by the end of the session	Cookies can be stored for a long time on the client
	Save Important information	Save non-critical user information

JSP (Java Server Page) JSP state management