You can use Aspose for Cloud API in any platform including Java. Nothing needs to be installed. You can just send HTTP requests and handle HTTP response. Please check Cloud API section of the documentation for Java examples and more details.
We have also wrapped our REST APIs in our Cloud SDKs. You can also use Aspose Cloud SDK for Java if you want to quickly get started with the Cloud APIs. Java SDK examples are also present in the documentation.
Please feel free to contact us in case you have further comments or questions.
Thanks for answer!
If you want to use Aspose for Cloud, you will have to send requests to Aspose so it is impossible to avoid api.aspose.com dependency.
If you want to build your own REST API, then yes you will have to use Aspose for .NET or Java libraries and wrap them in your web services to expose REST API service. We are also using Aspose for .NET libraries at the backend of our Cloud service.