This project adds a graphical user interface(GUI) for exporting data of OpenRefine projects in RDF format. The export is based on mapping the data to a template graph using the GUI. It also provides a service for reconciling data against SPARQL endpoints (e.g., DBpedia).
You need to have Java and OpenRefine installed on your machine.
- Java 8+
- OpenRefine 3.3+
- If it does not exist, create a folder named extensions/rdf-extension under your user workspace directory for OpenRefine. The workspace should be located in the following places depending on your operating system (see OpenRefine FAQ for more details):
- Linux ~/.local/share/OpenRefine
- Windows C:/Documents and Settings//Application Data/OpenRefine OR C:/Documents and Settings//Local Settings/Application Data/OpenRefine
- Mac OSX ~/Library/Application Support/OpenRefine
- Unzip the downloaded release (ensuring it is a rdf-extension-x.x.x-*.zip not a source code .zip or tar.gz) into the extensions/rdf-extension folder (step 1). It is recommended that you have an active internet connection during the first run of the extension, as it will try to download a set of predefined vocabularies (rdf, rdfs, owl and foaf). You can add them later also.
- Restart OpenRefine (OpenRefine usage instructions are provided in the user documentation)
- Clone this extension repository to your local machine
- Checkout the main branch
git checkout main - Run
mvn clean compileandmvn assembly:single - Unpack the zip file created in the
targetdirectory to a sub-directory of the extensions folder of OpenRefine e.g.,extensions/rdf-extension
If you have previously installed the extension you will need to replace it in the OpenRefine extensions directory with the newly built version.
If you are upgrading from an older version (prior to v1.0.0-rc4) you may see an error similar to the below when starting OpenRefine:
Exception in thread "main" java.lang.Error: class org.apache.lucene.index.IndexFormatTooOldException:
org.apache.lucene.index.IndexFormatTooOldException: Format version is not supported (resource
BufferedChecksumIndexInput(MMapIndexInput(path="C:\PATH\OpenRefine\cache\rdfExtension\export\luceneIndex
\segments_1"))): -11 (needs to be between 1071082519 and 1071082519).
This version of Lucene only supports indexes created with
release 5.0 and later.
This is due to an upgrade in the version of Lucene used.
To solve this you will need to remove the old Lucene index and restart OpenRefine, i.e., for the example above delete
C:\PATH\OpenRefine\cache\rdfExtension\export\luceneIndex.
For Linux this will be under ~/.local/share/openrefine/cache/rdfExtension/export/luceneIndex