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Using Gremlin with Amazon Neptune JDBC Driver

This driver supports using Gremlin for executing statements against Neptune.

Creating a connection

The connection string for Gremlin connections follows the following form:

jdbc:neptune:gremlin://[host];[port=portValue];[propertyKey1=value1];[propertyKey2=value2]..;[propertyKeyN=valueN]

Note: Gremlin configures the port as a property and not as a part of the connection string. If a port is not specified it defaults to 8182.

The following properties are available for Gremlin:

Property Key Description Accepted Value(s) Default value
logLevel Log level for application. In order of least logging to most logging: OFF, FATAL, ERROR, WARN, INFO, DEBUG, TRACE, ALL. INFO
authScheme Authentication mechanism to use. NONE (no auth), IAMSigV4 (IAM / SIGV4 logging). IAMSigV4, AWS SIGV4 credentials must be properly set up, including a region. See environment setup for IAM authentication on Neptune for more information.
serviceRegion If IAMSigv4 is selected, this region variable must be set for connecting to IAM authenticated Neptune instance String values. For example, us-east-1 NONE. For a list of regions see Neptune service regions. An alternative to setting this is through exporting the SERVICE_REGION environment variable as instructed in the link.
scanType To scan all nodes or only the first node when creating database schema. ALL (schema creation scans all nodes), FIRST (schema creation scans the first node only). ALL
connectionTimeout Amount of time to wait for initial connection in milliseconds. Integer values. 5000
connectionRetryCount Number of times to retry if establishing initial connection fails. Integer values. 3
sshUser The username for the internal SSH tunnel. If provided, options sshHost and sshPrivateKeyFile must also be provided, otherwise this option is ignored. String values. NONE
sshHost The host name for the internal SSH tunnel. Optionally the SSH tunnel port number can be provided using the syntax <ssh-host>:<port>. The default port is 22. If provided, options sshUser and sshPrivateKeyFile must also be provided, otherwise this option is ignored. String values. NONE
sshPrivateKeyFile The path to the private key file for the internal SSH tunnel. If the path starts with the tilde character (~), it will be replaced with the user's home directory. If provided, options sshUser and sshHost must also be provided, otherwise this option is ignored. String values. NONE
sshPrivateKeyPassphrase If the SSH tunnel private key file, sshPrivateKeyFile, is passphrase protected, provide the passphrase using this option. If provided, options sshUser, sshHost and sshPrivateKeyFile must also be provided, otherwise this option is ignored. String values. NONE
sshStrictHostKeyChecking If true, the 'known_hosts' file is checked to ensure the target host is trusted when creating the internal SSH tunnel. If false, the target host is not checked. Disabling this option is less secure as it can lead to a "man-in-the-middle" attack. If provided, options sshUser, sshHost and sshPrivateKeyFile must also be provided, otherwise this option is ignored. Boolean values. true
sshKnownHostsFile The path to the 'known_hosts' file used for checking the target host for the SSH tunnel when option sshStrictHostKeyChecking is true. The 'known_hosts' file can be populated using the ssh-keyscan tool. If provided, options sshUser, sshHost and sshPrivateKeyFile must also be provided, otherwise this option is ignored. String values. ~/.ssh/known_hosts

Important note:

The above properties are configurations that are shared across all query languages in the driver.

For all the Gremlin-specific properties take a look at their documentation.

Each Builder method listed in the documentation is accepted as a property. For example, "port(int port)" means that as a part of the connection string it may be configured as a property or added as a Key-Value Pair in Properties. See below for examples.

No authentication using string only

import java.sql.*;

class Example {
    static final String CONNECTION_STRING = "jdbc:neptune:gremlin://example.neptune.amazonaws.com;port=8182;authScheme=None";
    
    public static void main(String[] args) throws SQLException {
        Connection connection = DriverManager.getConnection(CONNECTION_STRING);
        connection.close();
    }
}

No authentication using Properties

Instead of having properties set in the connection string, you can also set Properties in order to get a connection.

import java.sql.*;
import java.util.Properties;

class Example {
    static final String CONNECTION_STRING = "jdbc:neptune:gremlin://example.neptune.amazonaws.com";
    
    public static void main(String[] args) throws SQLException {
        Properties properties = new Properties();
        properties.put("port", 8182);
        properties.put("authScheme", "None");
        
        Connection connection = DriverManager.getConnection(CONNECTION_STRING, properties);
        connection.close();
    }
}

IAM authentication

IAM is the standard way to access Neptune under an authorized account. Note that SSL is required for IAM authentication.

import java.sql.*;

class Example {
    static final String CONNECTION_STRING = "jdbc:neptune:gremlin://example.neptune.amazonaws.com;port=8182;authScheme=IAMSigV4;enableSsl=true;serviceRegion=us-east-1";
    
    public static void main(String[] args) throws SQLException {
        Connection connection = DriverManager.getConnection(CONNECTION_STRING);
        connection.close();
    }
}

Like above, Properties can be used to set the settings to enable IAM authentication.

import java.sql.*;
import java.util.Properties;

class Example {
    static final String CONNECTION_STRING = "jdbc:neptune:gremlin://example.neptune.amazonaws.com";
    
    public static void main(String[] args) throws SQLException {
        Properties properties = new Properties();
        properties.put("port", 8182);
        properties.put("authScheme", "IAMSigV4");
        properties.put("serviceRegion", "us-east-1");
        properties.put("enableSsl", true);
        
        Connection connection = DriverManager.getConnection(CONNECTION_STRING, properties);
        connection.close();
    }
}

Querying the database

Listing the table names

import java.sql.*;

class Example {
    static final String CONNECTION_STRING = "jdbc:neptune:gremlin://example.neptune.amazonaws.com;port=8182;authScheme=None";
    
    public static void main(String[] args) throws SQLException {
        // Create a connection
        try (Connection connection = DriverManager.getConnection(CONNECTION_STRING)) {
            // Get the MetaData of the database
            DatabaseMetaData metaData = connection.getMetaData();
            // Get the tables from the MetaData
            try (ResultSet results = metaData.getTables(null, null, "%", null)) {
                while (results.next()) {
                    // Get the table name from the results and print them
                    String tableName = results.getString("TABLE_NAME");
                    System.out.println(tableName);
                }
            }
        }
    }
}

Executing a statement

import java.sql.*;

class Example {
    static final String CONNECTION_STRING = "jdbc:neptune:gremlin://example.neptune.amazonaws.com;port=8182;authScheme=None";
    
    public static void main(String[] args) throws SQLException {
        String query = "g.V().hasLabel('country').valueMap()";
        try (
            // Create a connection
            Connection connection = DriverManager.getConnection(CONNECTION_STRING);
            // Create a statement
            Statement statement = connection.createStatement();
            // Execute a query
            ResultSet results = statement.executeQuery(query)
        ) {
            while (results.next()) {
                // Get the country name (desc) from the results and print them
                String countryName = results.getString("desc");
                System.out.println(countryName);
            }
        }
    }
}