Java operation cookie !!!

 

Java's operations on cookies are relatively simple. This section describes how to create and read cookies, and how to set the cookie lifecycle and Cookie Path.

 

Create a non-life cycle cookie, that is, the cookie disappears when the browser is closed. The Code is as follows:

 

1	HttpServletRequest request

2	HttpServletResponse response

3	Cookie cookie = new Cookie("cookiename","cookievalue");

4	response.addCookie(cookie);

 

Create a cookie with a lifecycle. You can set its lifecycle.

 

1	cookie = new Cookie("cookiename","cookievalue");

2

3	cookie.setMaxAge(3600);

Unit: seconds !!!!!!!

4

5	// Set the path, that is, the cookie can be accessed under the project. If no path is set, only the Cookie Path and its sub-path can be accessed.

6

7	cookie.setPath("/");

8	response.addCookie(cookie);

 

The following describes how to read a cookie and read the cookie Code as follows:

 

1	Cookie[] cookies = request.getCookies();// Obtain a cookie array.

2	for(Cookie cookie : cookies){

3	cookie.getName();// get the cookie name

4	cookie.getValue(); // get the cookie value

5

}

 

The above is the basic operation for reading and writing cookies. In practice, we 'd better encapsulate it. For example, to add a cookie, we are concerned with the name, value, and lifecycle of the cookie. Therefore, we need to encapsulate a function and pass in a response object, the addcookie () code is as follows:

01

/**

02	* Set cookie

03	* @param response

04	* @ Param name Cookie name

05	* @ Param value cookie value

06	* @ Param maxage cookie lifecycle in seconds

07

*/

08	public static void addCookie(HttpServletResponse response,String name,String value,int maxAge){

09	Cookie cookie = new Cookie(name,value);

10	cookie.setPath("/");

11	if(maxAge>0)  cookie.setMaxAge(maxAge);

12	response.addCookie(cookie);

13

}

 

When reading cookies, we want to encapsulate a function to facilitate our operations. As long as we provide the cookie name, we can get the cookie value. With this idea, it is easy to encapsulate the cookie into the map, so the following encapsulation is performed.

 

01

/**

02	* Get cookie by name

03	* @param request

04	* @ Param name Cookie name

05

* @return

06

*/

07	public static Cookie getCookieByName(HttpServletRequest request,String name){

08	Map<String,Cookie> cookieMap = ReadCookieMap(request);

09	if(cookieMap.containsKey(name)){

10	Cookie cookie = (Cookie)cookieMap.get(name);

11	return cookie;

12

}else{

13	return null;

14

}

15

}

16

17

18

19

/**

20	* Encapsulate cookies in Map

21	* @param request

22

* @return

23

*/

24	private static Map<String,Cookie> ReadCookieMap(HttpServletRequest request){

25	Map<String,Cookie> cookieMap = new HashMap<String,Cookie>();

26	Cookie[] cookies = request.getCookies();

27	if(null!=cookies){

28	for(Cookie cookie : cookies){

29	cookieMap.put(cookie.getName(), cookie);

30

}

31

}

32	return cookieMap;

33

}