An example of a Neo4j transaction event handler (for a blog post)

neo4j-tx-event-handler-101.java

@Test
public void showSimpleEventHandling() {
    GraphDatabaseService database = new TestGraphDatabaseFactory().newImpermanentDatabase();

    database.registerTransactionEventHandler(new TransactionEventHandler<Void>() {
        @Override
        public Void beforeCommit(TransactionData data) throws Exception {
            System.out.println("Committing transaction");
            return null;
        }

        @Override
        public void afterCommit(TransactionData data, Void state) {
            System.out.println("Committed transaction");
        }

        @Override
        public void afterRollback(TransactionData data, Void state) {
            System.out.println("Transaction rolled back");
        }
    });

    Transaction tx = database.beginTx();
    try {
        database.createNode();
        tx.success();
    } finally {
        tx.finish();
    }

    /**
     prints:
     > Committing transaction
     > Committed transaction
     **/
}