Create and access nodes and relationships.

To begin with, we define the relationship types we want to use:

private static enum ExampleRelationshipTypes implements RelationshipType
{
    EXAMPLE
}

The next step is to start the database server:

GraphDatabaseService graphDb = new EmbeddedGraphDatabase( DB_PATH );
registerShutdownHook( graphDb );

As seen, we register a shutdown hook that will make sure the database shuts down when the JVM exits. Now it’s time to interact with the database:

// Encapsulate operations in a transaction
Transaction tx = graphDb.beginTx();
try
{
    Node firstNode = graphDb.createNode();
    firstNode.setProperty( NAME_KEY, "Hello" );
    Node secondNode = graphDb.createNode();
    secondNode.setProperty( NAME_KEY, "World" );

    firstNode.createRelationshipTo( secondNode,
        ExampleRelationshipTypes.EXAMPLE );

    String greeting = firstNode.getProperty( NAME_KEY ) + " "
        + secondNode.getProperty( NAME_KEY );
    System.out.println( greeting );

At this point this is how the database looks:

In this case we’ll remove the data before committing:

    // let's remove the data before committing
    firstNode.getSingleRelationship( ExampleRelationshipTypes.EXAMPLE,
            Direction.OUTGOING ).delete();
    firstNode.delete();
    secondNode.delete();

    tx.success();
}
finally
{
    tx.finish();
}

Finally, shut down the database server when the application finishes:

graphDb.shutdown();

Full source code: EmbeddedNeo4j.java