Install

Prerequisites

Java and OpenRefine must be installed.

• Java 11 to 21 (see notes below and Java JDKs...)
• OpenRefine 3.6.x to 3.10-SNAPSHOT (as of 03/18/2025)

NOTE: The author has tested the current RDF Transform using OpenJDK 17.
NOTE: For Java Standard Editions after Java 8, you cannot install the JRE separate from the JDK unless you use a site like JustJ and their JRE Downloads. RDF Transform has not been tested using JustJ installs and is beyond the scope of this project.

Additionally, if you need to compile, you will need Maven.

• Java JDK 11 to 21
• Apache Maven 3.6 or better
• OpenRefine 3.x-SNAPSHOT Source (optional)

From Compiled Release

The compiled release file is the "Easy Button" to get RDF Transform installed as an extension to OpenRefine. Follow these instructions to get it running.

1. If it does not exist, create a folder named extensions under your user workspace directory for OpenRefine. The workspace should be located in the following places depending on your operating system (see the OpenRefine FAQ for more details):
   • Linux ~/.local/share/OpenRefine
   • Windows C:/Documents and Settings/<user>/Application Data/OpenRefine OR C:/Documents and Settings/<user>/Local Settings/Application Data/OpenRefine
   • Mac OSX ~/Library/Application Support/OpenRefine
   As an alternative (but not recommended), use the OpenRefine application's extensions directory instead.
2. Unzip the downloaded release (ensuring it is a rdf-transform-x.x.x.zip and not a source code .zip or .tar.gz) in the extensions folder (within the directory of step 1). This will create an rdf-transform directory containg the extension.
3. Start (or restart) OpenRefine (see the OpenRefine User Documentation)

NOTE: It is recommended that you have an active Internet connection when using the extension as it can download ontologies from specified namespaces (such as rdf, rdfs, owl and foaf) to supplement property selection. You can (re)add namespaces and specify whether to download the ontology (or not) from the namespace declaration URL. If you must run OpenRefine from an offline location, you can copy the ontologies to files in your offline space and use the "from file" feature to load the ontologies.

Java JDKs, JREs, and JVMs! Oh, My!

Java does not supply simple JRE installs for versions after 8 (1.8), so you might want to create your own. However, many Linux distribution provide a JRE package install that are fairly inclusive and may work with OpenRefine...YMMV.

You can create your own JRE from a late model JDK install (9+) that includes all the required modules by performing the following command:

jlink --compress=2 --strip-debug --add-modules=java.base,java.compiler,java.datatransfer,java.logging,java.desktop,java.instrument,java.management,java.management.rmi,java.naming,java.net.http,java.prefs,java.rmi,java.scripting,java.se,java.security.jgss,java.security.sasl,java.smartcardio,java.sql,java.sql.rowset,java.transaction.xa,java.xml,java.xml.crypto --output ~/JRE

Change the output ~/JRE to whatever directory you like (it will create it if it doesn't exist).

The --add-modules parameters get its modules from:

java --list-modules

using whatever Java version you have currently selected. The jlink command is just using the listed "java" modules and ignoring the "jdk" modules.

You can run OpenRefine using this newly created JRE directory by setting the JAVA_HOME environment variable to it and running the OpenRefine script file. A one-liner for Linux, while in the OpenRefine directory, is:

JAVA_HOME=~/JRE ./refine

To recreate the JRE, remove the JRE directory, adjust the jlink command, and re-execute it. For Linux, to remove the JRE directory, do:

rm -rf ~/JRE