It seems like that the odata4j library is not going to support OData v4.
You can try follow the Apache Olingo project instead if you would like to use a Java library that supports OData v4. It is clearly stated on the project homepage that although it currently only supports v2, OData v4 is in scope and people are proactively working on it. It is also an open source project and you can view the detailed working progress of it here.