Cloudinary provides a library for simplifying the integration even further, along with Java sample code for uploading and transforming images.
You can find sample projects that demonstrate common Cloudinary's usage in Java here:
These projects are based on the Spring MVC v3.2:
A fully working web application that allows you to uploads photos, maintain a database with references to them, list them with their metadata, and display them using various cloud-based transformations. Image uploading is performed both from the server side and directly from the browser using a jQuery plugin.