Since, RFC is proprietary to SAP, you can’t use a Java SE or Java EE API to invoke RFC function. You can use a specialized connector library called, SAP Java Connector. This library is used to connect database systems. Classes and interfaces are provided to build RFC function calls, connections and parse through results.
The SAP Java Connector library installed on SAP HCP is stripped down from standalone version. And some items missing in SAP HCP version of the connector include server-side program support and dynamic connection configuration.
In terms of SAP HCP, the SAP Java Connector library is created into Connector Service, which means that you don’t have to bundle library within web applications. Instead of coding connection parameters, you can use RFC destination object built in SAP HCP Cockpit as starting point for creating a connection object.
Apart from data storage capabilities, content repositories provide value-added features like Indexing, Versioning, Security using access control lists (ACLs) and Advanced query and search capabilities.
In SAP HCP, Document Service plays role of content repository, which can be used to store and retrieve unstructured data. The content in Document Service is regulated and organized in a way similar to that within a file system. Document Service is primarily intended for use as a full-scale content repository. But, it can also be used as a mock file system when the application requires the file system. Thus, though the widespread use of Document Service is not primarily ideal, it’s certainly impossible!
When a repository is created, it is preassigned with a root-level folder. Here from this folder, one can further sub-divide by defining subfolders and filling them with documents. These functions are carried out using methods from org.apache.chemistry.opencmis.client.api.Folder interface.