Can't read joystick values in Java

[nubie]

Our team is trying to implement a simple mecanum drive in Java, but whenever we try to set a motor speed based on a joystick value, the motor simply does nothing. No error is thrown, but it does not spin.

We are extending the SimpleRobot class. We are initializing the joysticks with:

private Joystick leftStick;

public RobotTemplate() {
leftStick = new Joystick(1);

and then later on...

drivetrain.tankDrive(leftStick, rightStick);

//or

leftMotor.set(leftStick.getX());

We just switched from C++ to Java and we were able to use the joysticks fine in our C++ program, so we don't think it's a control system issue.

Any help would be greatly appreciated! Thanks.