Aliases

The BALD CLI and library allow you to specify property and resource aliases to be resolved in the NetCDF metadata, as described in the draft specification.

CLI

You can provide aliases as a set of RDF files. Use the --alias or -a option to specify the locations of alias files as a comma-delimited list. These can be the paths of files on the local file system, or the URLs of remote resources.

Note that the alias paths must have a suitable extension in order to be parsed correctly.

Example

java -jar bald-cli.jar --alias /path/to/alias.ttl /path/to/netcdf.nc /path/to/graph.ttl

Note

If your alias files are remote resources and you are using a proxy server, you must provide the proxy host and port with the -Dhttp.proxyHost and -Dhttp.proxyPort JVM arguments. See here for official documentation.

Library

For simple usage, use the NetCdfLd.convert method as described here.

Alternatively, you can provide aliases as an Apache Jena model. You can create a Model instance programmatically, or by reading in an RDF file. See the Jena docs for more information.

Pass a model to the ModelAliasDefinition.create method to create an AliasDefinition instance. You may also create your own implementation of AliasDefinition.

You can pass this instance to the NetCdfBinaryArray.create method to create a binary array with the given aliases.

Note that you can pass both a contextual prefix mapping, and an alias definition to create a BinaryArray with both.

Model aliasModel = ModelFactory.createDefaultModel().read("/path/to/alias.ttl", "ttl");
AliasDefinition alias = ModelAliasDefinition.create(aliasModel);
BinaryArray ba = NetCdfBinaryArray.create("/path/to/input.nc", "http://test.binary-array-ld.net/example", null, alias, null);
Model model = ModelBinaryArrayConverter.convert(ba);

try (OutputStream output = new FileOutputStream("/path/to/output.ttl")) {
    model.write(output, "ttl");
}