Accessing multiple database from a Java web application using JPA/EclipseLink/EJB

Question

I have built a simple SOAP java application(server side) and I am using Glassfish4,JPA/EclipseLink,EJB. I have set the db connections(resources/poo

Answer 1

When dealing with one app and multiple DBs EclipseLink provides two solutions. Which one is better suited for you depends on your use-case, if

Users need to map expose multiple persistence units as a single persistence context within an application.

Take a look at Using Multiple Databases with a Composite Persistence Unit

If your case is that

Multiple application clients must share data sources, with private access to their data environment.

than take a look at Tenant Isolation Using EclipseLink

Alternatively, this blog post describes a way of designing a multi-tenancy, without binding to vendor specific functionality

UPDATE with respect to the comment

I don't think that the type of dynamic data source routing that you're after exists as a ready made construct of glassfish. But it should not be too hard to implement it either. You should take a look at the TomEE's dynamic datasource api and the reference implementation they provided. You should be able to write your own router based on it without too much issues