import org.neo4j.driver.*;

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

public class SmallExample { // Driver objects are thread-safe and are typically made available application-wide. Driver driver;

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

private void addPerson(String name)
{
    // Sessions are lightweight and disposable connection wrappers.
    try (Session session = driver.session())
    {
        // Wrapping a Cypher Query in a Managed Transaction provides atomicity
        // and makes handling errors much easier.
        // Use `session.writeTransaction` for writes and `session.readTransaction` for reading data.
        // These methods are also able to handle connection problems and transient errors using an automatic retry mechanism.
        session.writeTransaction(tx -> tx.run("MERGE (a:Person {name: $x})", parameters("x", name)));
    }
}

private void printPeople(String initial)
{
    try (Session session = driver.session())
    {
        // A Managed transaction is a quick and easy way to wrap a Cypher Query.
        // The `session.run` method will run the specified Query.
        // This simpler method does not use any automatic retry mechanism.
        Result result = session.run(
                "MATCH (a:Person) WHERE a.name STARTS WITH $x RETURN a.name AS name",
                parameters("x", initial));
        // Each Cypher execution returns a stream of records.
        while (result.hasNext())
        {
            Record record = result.next();
            // Values can be extracted from a record by index or name.
            System.out.println(record.get("name").asString());
        }
    }
}

public void close()
{
    // Closing a driver immediately shuts down all open connections.
    driver.close();
}

public static void main(String... args)
{
    SmallExample example = new SmallExample("bolt://localhost:7687", "neo4j", "password");
    example.addPerson("Ada");
    example.addPerson("Alice");
    example.addPerson("Bob");
    example.close();
}