citygml4j is an open source Java class library and API for facilitating work with the OGC City Geography Markup Language (CityGML). citygml4j makes it easy to read, process, and write CityGML datasets, and to develop CityGML-aware software applications.

citygml4j binds the XML Schema definitions of CityGML to a well-defined Java object model. CityGML instance documents are deserialized into a tree of corresponding Java objects representing the content and organization of the instance document. This XML binding approach allows Java developers to incorporate CityGML data and processing functions in Java applications without having to know XML or low-level XML processing APIs. Instead of thinking about parsing XML data, developers can focus on the business logic and work with well-defined CityGML objects. After processing the CityGML data, the Java content tree can be easily serialized back into a CityGML instance document.

Follow citygml4j on GitHub: https://github.com/citygml4j