Popular Enterprise information systems (EIS) provide REST API and JCA to integrate with Java EE web applications. When REST API is avialable, why & when we should go for JCA based integration ?
For example, Salesforce provides excellent REST API(s). Also there are developers who develop JCA connectors for Salesforce, like this. I am unable to justify why I should go for JCA when REST is so flexible & easy to integrate with any application.