netCDF-Java/CDM

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, BUFR, and many others. By itself, the netCDF-Java library can only write netCDF-3 files. It can write netCDF-4 files by using JNI to call the netCDF-C library. It also implements Unidata's Common Data Model (CDM) to provide data geolocation capabilities.

For more information about netCDF-Java/CDM, see the netCDF-Java web page at

• http://www.unidata.ucar.edu/software/netcdf-java/

and the CDM web page at

https://docs.unidata.ucar.edu/thredds/netcdf-java/5.0/userguide/common_data_model_overview.html

You can obtain a copy of the latest released version of netCDF-Java software from

• http://www.unidata.ucar.edu/downloads/netcdf/

More documentation can be found at

• https://docs.unidata.ucar.edu/thredds/netcdf-java/5.0.0/userguide/index.html

A mailing list, netcdf-java@unidata.ucar.edu, exists for discussion of all things netCDF-Java/CDM including announcements about netCDF-Java/CDM bugs, fixes, enhancements, and releases. For information about how to subscribe, see the "Subscribe" link on this page

• http://www.unidata.ucar.edu/mailing_lists/archives/netcdf-java/

For more general netCDF discussion, see the netcdfgroup@unidata.ucar.edu email list.

We appreciate feedback from users of this package. Please send comments, suggestions, and bug reports to support-netcdf-java@unidata.ucar.edu. Please identify the version of the package.

NetCDF Markup Language (NcML)

NcML is an XML representation of netCDF metadata, it approximates the header information one gets from a netCDF file with the "ncdump -h" command. NcML is similar to the netCDF CDL (network Common data form Description Language), except, of course, it uses XML syntax.

Beyond simply describing a netCDF file, it can also be used to describe changes to existing netCDF files. A limited number of tools, mainly netCDF-Java based tools, support these features of NcML

For more information about NcML, see the NcML web page at

https://docs.unidata.ucar.edu/thredds/netcdf-java/5.0/userguide/ncml_overview.html

THREDDS Catalogs

THREDDS Catalogs can be thought of as representing logical directories of on-line data resources. They are encoded as XML and provide a place for annotations and other metadata about the data resources. These XML documents are how THREDDS-enabled data consumers find out what data is available from data providers.

THREDDS Catalog documentation (including the specification) is available at

• http://www.unidata.ucar.edu/software/thredds/current/tds/catalog/

Licensing

netCDF-Java is released under the BSD-3 licence, which can be found can be found here.

Furthermore, this project includes code from third-party open-source software components:

• Gretty: for details, see buildSrc/README.md
• ERDDAP: for details, see waterml/README.md
• JUnit: for details, see testUtil/README.md

Each of these software components have their own license. Please see docs/src/private/licenses/third-party/.

How to use

The latest released and snapshot software artifacts (e.g. .jar files) are available from Unidata's Nexus repository:

• https://artifacts.unidata.ucar.edu/#browse/browse/components:unidata-all

To build netCDF-java from this repository, follow this tutorial.

To use the netCDF-Java library as a depenency using maven or gradle, follow these instructions.