For my educational JSP-project (Servlets, Java EE) I have to implement the database in Java. In the index page, I also execute function to build the database (not MySQL, but something like `HashMap` based structure with links to objects) and fill it with basic data. My issue is that I can't make this «database» global and can't access to this structure from every page of the site.

How can I pass pointer/link to this structure to all JSP-site page?