netCDF-Java

Welcome to the 6.x line of development of the netCDF-Java library!

Looking for the 5.x line of development? See branch maint-5.x. Version 4.6 is no longer supported outside of the context of the THREDDS Data Server (TDS). If you are looking for that codebase, it can be found at https://github.com/Unidata/thredds/tree/main.

The netCDF Java library provides an interface for scientific data access. It can be used to read scientific data from a variety of file formats including netCDF, HDF, GRIB, and BUFR. By itself, the netCDF-Java library can only write netCDF-3 files. It can write netCDF-4 files by using JNA to call the netCDF-C library. The library implements Unidata's Common Data Model (CDM) to provide data geolocation capabilities.

Documentation can be found at https://docs.unidata.ucar.edu/netcdf-java/. The User's Guide contains information on how to use the library in your project, a tutorial, and useful upgrade tips.

Requirements

• Java 8 or above

Each pull requests runs a subset of tests using Java 8, 11, and 14 (AdoptOpenJDK and Zulu). Currently, netCDF-C version 4.7.4 is used by our netCDF-4 write tests. The full test suite runs nightly (this take a little over an hour). More information on our test environment can be found at https://github.com/unidata/thredds-test-environment#thredds-test-environment-highlights.

Using netCDF-Java in your project

The latest release and snapshot artifacts are available from Unidata's Nexus repository. To use the netCDF-Java artifacts as dependencies using maven or gradle, follow these instructions. At a minimum, you will need to reference the Unidata artifacts server (https://artifacts.unidata.ucar.edu/repository/unidata-all/) and use the cdm-core artifact, which has a groupId of edu.ucar and an artifactId of cdm-core. We also provide a maven BOM (groupId: edu.ucar, artifactId: netcdf-java-bom) and a Gradle Java Platform (groupId: edu.ucar, artifactId: netcdf-java-platform) for convenience. To build netCDF-java from this repository, follow this tutorial.

Participation

As contributors, creators, stewards, and maintainers of software managed by the Unidata Program Center, we agree to follow the UCAR Codes of Conduct to foster a safe, productive, welcoming and inclusive experience for everyone. Please familiarize yourself with these Codes of Conduct, especially the Contributor Code of Conduct. In the coming weeks, we'll be opening the GitHub Discussions area on this repository as a place for discussion of all things netCDF-Java. Unidata will continue to host community mailing list, netcdf-java@unidata.ucar.edu, as a secondary outlet for release announcements, and as a place for those who do not wish to use GitHub.

We appreciate feedback from users of this package. The GitHub Discussions area (once active) will be a great place to post comments and suggestions, and discuss the future direction of the library. For bug reports, please open an issue on this repository. Please identify the version of the package as well as the version/vendor of Java you are using. For potential security issues, please contact security@unidata.ucar.edu directly.

Contributors

Are you looking to contribute to the netCDF-Java efforts? That's great! Please see our contributors guide for more information!

Older versions

Prior to v5.0.0, the netCDF-Java library and the THREDDS Data Server (TDS) were built and released together. Starting with version 5, the two packages were decoupled, allowing new features and bug fixes to be implemented in each package separately, and released independently. Releases prior to v5.0.0 were managed at https://github.com/unidata/thredds, which holds the combined code based used by v4.6.x and earlier. If you are looking for the TDS, its new home is located at https://github.com/unidata/tds.