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