Problem with Java Client

Hi, I’m really new to InfluxDB and I’m using the DB to perform some tests in my Java application, running on an Ubuntu 16.04 server, for a college project.
The library I’m using is influxdb-java, with all of its dependencies and the DB is using its default configuration.
But, when I try to connect to the DB, the connection doesn’t happen.
So, the following line will throw a nullPointer to the object influxDB, causing a nullPointerException later.

   InfluxDB influxDB = InfluxDBFactory.connect("", "root", "root");

What could it be? Maybe a problem with the DB settings?
Thanks for the help!

@allexandresampaio is there an influxd instance instance running at Also can you post the full error?