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 is free software under the GNU LGPL Version 3.0. See the LICENSE.txt file for more details.

The latest stable release of citygml4j is 2.2.1.

Download the citygml4j 2.2.1 release binariers here. Previous releases are available from the releases section.

• To file bugs found in the software create a GitHub issue.
• To contribute code for fixing filed issues create a pull request with the issue id.
• To propose a new feature create a GitHub issue and open a discussion.

citygml4j depends on JRE 7 or higher. The project uses Apache Ant as build tool. To build the library, run the build.xml file from the root of the repository with dist as target.

% ant dist

This will create a folder citygml4j-<version> with the following subfolders:

• javadoc -- the Javadoc documentation
• lib -- the citygml4j library and its mandatory dependencies
• license -- license information
• samples -- a collection of citygml4j sample programs

Simply put the citygml4j-<version>.jar library file and its mandatory dependencies from the lib folder on your classpath to start developing with citygml4j. Have fun :-)

citygml4j is also available as Maven artifact from the Central Maven Repository. To add citygml4j to your project with Maven, add the following code to your pom.xml. You may need to adapt the citygml4j version number.

<dependency>
  <groupId>org.citygml4j</groupId>
  <artifactId>citygml4j</artifactId>
  <version>2.2.1</version>
</dependency>

citygml4j provides a number of sample programs that demonstrate the use of the library. Download the library or build it from source with Apache Ant as described above. This will deploy the sample programs in the citygml4j-<version>/samples folder.

The sample programs are organized into subfolders, each addressing a different use case of citygml4j. Ant build.xml files are provided to easily run the sample programs. Note that the build.xml files may contain more than just the default target.

OGC CityGML is an open data model and XML-based format for the storage and exchange of semantic 3D city models. It is an application schema for the Geography Markup Language version 3.1.1 (GML3), the extendible international standard for spatial data exchange issued by the Open Geospatial Consortium (OGC) and the ISO TC211. The aim of the development of CityGML is to reach a common definition of the basic entities, attributes, and relations of a 3D city model.

CityGML is an international OGC standard and can be used free of charge.