Implementing a custom ConcurrentHashMap for database web application

Im working on a project for an internship & I'm trying to go about making a subclass of ConcurrentHashMap where the key is going to be the primary key for a database in MS SQL Server 2008, and the value is an FTP link to an associated image, using Apache Commons Net library for the FTP access, and that's all working.

My question is if it's advisable to use ConncurrentHashMap for this, since the code will be running from a managed web application platform called m-Power (for more info http://ift.tt/1s0wbyG) as a means to prepare data for Bulk Upload into Salesforce.

The reasons I thought to use ConcurrentHashMap was since multiple users would be using the web form at the same time and would therefore be adding/updating records in the SQL Server database at the same time. I also needed a custom implementation since I can add utility functions to the custom class. Any help is welcome :)