Please elaborate XMLHttpRequest Object further?

Question

I am working on an app with Java and Struts2.
I fetch all data from my DB to an Object(eg.XXX) List at once while Tomcat(7) is coming up. Then according to user selection, I am trying to get data from the same List by doing Ajax call. But it is failing and getting an empty list. I don't want to use session.
Can I use and global object list for this?? An Example will be more helpful.

Answer 1

XMLHttpRequest is the core object in AJAX technology regardless of any implementation. XMLHttpRequest object is used to exchange data with a server seamlessly. Basically JavaScript uses this Object to exchange XML as well as text data between client and server. An AJAX implementation uses this object and communicate with server but it doesn't require the complete page to be refreshed.