CLI

Instead of using the .jar you can also use Maven to execute the Databus Client.

Requirements

• Java: JDK 8 or JDK 11

• Maven: ^3.6

Installation

git clone https://github.com/dbpedia/databus-client.git
cd databus-client
mvn clean install

Execution example

Select Query

First we need to specify, the data we want to download.

Note: It is best practice to write a query to a file and pass this file as source, instead of passing the query directly as a string.

echo "PREFIX dcat:   <http://www.w3.org/ns/dcat#>
PREFIX databus: <https://dataid.dbpedia.org/databus#>

SELECT ?file WHERE
{
        GRAPH ?g
        {
                ?dataset databus:artifact <https://dev.databus.dbpedia.org/tester/testgroup/testartifact> .
                { ?distribution <http://purl.org/dc/terms/hasVersion> '2023-06-23' . }
                ?dataset dcat:distribution ?distribution .
                ?distribution databus:file ?file .
        }
}" > query.sparql 

Execute Client

bin/DatabusClient \
-s query.sparql \
-e https://dev.databus.dbpedia.org/sparql
-f jsonld \
-c gz

You will find more information if you set the flag-h or in CLI usage.

Separate downloader or converter

The converter and downloader of the Databus Client can be used separately.

Databus based downloader

Since the parameters compression and format both have the default value equal, the Databus Client is a pure downloader if you do not pass any arguments for compression and format.

bin/DatabusClient -s query.sparql

Compression and format converter

If you select already existing files as the source, the client does not use the download module and behaves like a pure converter.

bin/DatabusClient -s query.sparql -f ttl -c gz