HikariCP data source and usage

public class HikariCPFactory {
    private static final Logger LOGGER = LoggerFactory.getLogger(HikariCPFactory.class);

    @Override
    public DataSource apply(Config config) {
        LOGGER.debug("ConnectionPool initializing...");
        HikariConfig hc = new HikariConfig();
        // optional
        if (config.hasPath("jdbc.driver")) {
            hc.setDriverClassName(config.getString("jdbc.driver"));
        } else {
            hc.setDriverClassName("org.postgresql.Driver");
        }
        hc.setJdbcUrl(databaseUrl(config));
        hc.setUsername(config.getString("jdbc.username"));
        hc.setPassword(config.getString("jdbc.password"));

        // init cp specific properties
        hc.setInitializationFailFast(true);
        hc.setConnectionTestQuery("SELECT 1");
        if (config.hasPath("hikaricp")) {
            // enumerate all properties
            Config config0 = config.getConfig("hikaricp");
            Set<Map.Entry<String, ConfigValue>> set = config0.entrySet();
            for (Map.Entry<String, ConfigValue> entry : set) {
                hc.addDataSourceProperty(entry.getKey(), entry.getValue());
            }
        }
        LOGGER.debug("ConnectionPool initialized {}", hc);
        return new HikariDataSource(hc);
    }

    @SuppressWarnings("Duplicates")
    public static String databaseUrl(final Config config) {
        String protocol = config.getString("jdbc.protocol");
        String host = config.getString("jdbc.host");
        int port = config.getInt("jdbc.port");
        String database = config.getString("jdbc.database");
        return protocol + "//" + host + ":" + port + "/" + database;
    }
}

/// usage

        HikariCPFactory hcp = new HikariCPFactory();
        dsApple = hcp.apply(fallback(config, "apple"));
        dsSpotify = hcp.apply(fallback(config, "spotify"));

/// where
    public static Config fallback(Config config, String namespace) {
        // we need to be able to get, for example, "spotify.jdbc.username"
        // when we have defined "jdbc.username" only
        return config.getConfig(namespace)
            .withFallback(config);
    }

/// config
jdbc {
  driver = org.postgresql.Driver
  protocol = "jdbc:postgresql:"
  host = localhost
  port = 5432
  username = "postgres"
  password = "postgres"
  database = my_db
}
spotify {
  jdbc.host = "cloud.us-west-2.rds.amazonaws.com"
  jdbc.database = spotify_db
}
apple {
  jdbc.host = "cloud.us-west-2.rds.amazonaws.com"
  jdbc.database = apple_db
}