Java quick start

At the end of this guide, you will have created a simple Java console Hello, World! program that connects to the Memgraph database and executes simple queries.

Prerequisites

For this guide you will need:

• A running Memgraph instance. If you need to set up Memgraph, take a look at the Installation guide.
  caution

  In order for this driver to work, you need modify configuration setting --bolt-server-name-for-init. When running Memgraph, set --bolt-server-name-for-init=Neo4j/.

• Java 8, 11, 17 or 19 installed.

Basic Setup

We'll be using Eclipse IDE 2022-12 on MacOS to connect a simple Java console application to a running Memgraph instance using Maven. If you're using a different IDE, the steps might be slightly different, but the code is probably the same or very similar.

Let's jump in and connect a simple program to Memgraph.

1. Open Eclipse and create a new Maven project.
2. Select the Create a simple project option.
3. For the Group Id field put com.memgraph.app and for Artifact Id put my-app . Afterwards, click the Finish button.
4. Open the pom.xml file and add the dependencies inside your project:

<dependencies>
    <dependency>
      <groupId>org.neo4j.driver</groupId>
      <artifactId>neo4j-java-driver</artifactId>
      <version>5.4.0</version>
    </dependency>
  </dependencies>

5. Create the HelloWorld.java program and copy the following code:

import org.neo4j.driver.AuthTokens;
import org.neo4j.driver.Driver;
import org.neo4j.driver.GraphDatabase;
import org.neo4j.driver.Query;

import static org.neo4j.driver.Values.parameters;

public class HelloWorld implements AutoCloseable
{
    private final Driver driver;

    public HelloWorld( String uri, String user, String password )
    {
        driver = GraphDatabase.driver( uri, AuthTokens.basic( user, password ) );
    }

    public void close() throws Exception
    {
        driver.close();
    }

    public void printGreeting( final String message )
    {
        
        try (var session = driver.session()) {
            var hello = session.executeWrite( transaction -> {
            var query = new Query("CREATE (a:Greeting) SET a.message = $message RETURN 'Node ' + id(a) + ': ' + a.message", parameters("message", message));
            var result = transaction.run(query);
            return result.single().get(0).asString();
            });
            System.out.println(hello);
        }
    }
    
    public static void main( String... args ) throws Exception
    {
        try ( HelloWorld greeter = new HelloWorld( "bolt://localhost:7687", "", "" ) )
        {
            greeter.printGreeting( "Hello, World!" );
        }
    }
}

Once you run the program, you should see an output similar to the following:

Node 1: Hello, World!

info

Memgraph created Bolt Java Driver which can be used to connect to a running Memgraph instance. We still recommend you use the above mentioned driver.

Where to next?

For real-world examples of how to use Memgraph, we suggest you take a look at the Tutorials page. You can also browse through the How-to guides section to get an overview of all the functionalities Memgraph offers.