Connect to Neo4j with GraalVM languages

Connect to Neo4j from different programming languages using GraalVM.

Setup steps (basic GraalVM and Neo4j install):

1. Download Neo4j Desktop, community server, or start up a sandbox from neo4j.com

2. Follow download instructions to set up the database and start it

3. Download and install GraalVM SDK. GraalVM docs shows one way, but I used SDKMAN! to install it and set GraalVM’s Java (currently 20.3.0.r11-grl) as my default SDK.

4. Install any GraalVM languages you intend to use with the GraalVM Updater (gu). Use command syntax gu install <language>. Note: there may be a couple of other steps for dependencies to run a language, see the docs for each language.

5. Create and start an instance of Neo4j (if you are using Neo4j Sandbox, then this is already done for you).

Steps to run the examples:

1. Download Java driver (4.0.3) and reactive stream (1.0.3) dependencies.

2. Clone this repository and open in your preferred IDE

3. For each program language you intend to run, open the file and change the password on the authTokens.basic('neo4j', 'Testing123') line to be the password you set for your database. Note: If using Neo4j Sandbox, you will also need to modify the line above the authTokens with the sandbox connection BOLT URL.

4. Save and close the program(s), then build the project

5. Navigate to src/main/java folder and run one of the programs using the related command below.

#Python
graalpython --jvm graalvm-test.py

#Javascript
js --jvm neo4j-graalvm-javascript-example.js

#R
Rscript --jvm neo4j-graalvm-fastr-example.R

#Ruby
#Ruby does not (yet?) support adding Java dependencies to classpath, so have to set them on the command line
export CLASSPATH=../../../target/lib/neo4j-java-driver-4.0.3.jar:../../../target/lib/reactive-streams-1.0.3.jar
truffleruby --jvm --vm.cp=$CLASSPATH neo4j-graalvm-ruby-example.rb

Resources

• GraalVM documentation

• GraalVM language reference manual

• Neo4j downloads

• Neo4j developer guides