JSP / Servlets会话+ PHP：跟踪会话 - JSON /数据库或HttpSessionListener？

Question

I have implemented a Servlet, and a PHP site is accessing that Servlet to retrieve data. I'm wondering what is the best method to store a session variable, or whether I should store it at all.

Variables which need to be stored include an ArrayList, and other objects.

I've thought through about 3 possibilities:

(1) Implement the HttpSessionListener, and store each session (when it's created) into a static SessionMap. Then delete the session once it is destroyed.

(2) Store everything in JSON. So I'll have to serialize/deserialize each Object and pass it back and forth. (I have a list of items in each ArrayList/Object I want to keep track of between user clicks.)

(3) Store the information in MongoDB (just to pick one), using the SessionID as the primary key.

What do you guys think?

Answer 1

I rather like a combination of all three.

1. Has the advantage of simplicity - no need to go to a database if there's a session available.
2. JSON is lightweight, and it's the language of the browser.
3. Storing items in a database and retrieving them using session ID allows the possibility of users starting a session, leaving it in an incomplete state, and coming back later to pick up where they left off. The database might be a nice way to store information if the memory requirements become large and cumbersome.

I don't believe it has to be an exclusive choice.