[Patrick Chiang]

Try putting:

System.out.println(testJoystick.getY());

somewhere in your code.

This will print out the values of your joystick so you can see if the problem is with the jaguars or with the joystick.

Also, as people have mentioned, you need to put the code in a loop.

These are the possible loops for an IterativeRobot implementation:

RobotInit
DisabledInit
DisabledPeriodic/DisabledContinuous
AutonomousInit
AutonomousPeriodic/AutonomousContinuous
TeleopInit
TeleopPeriodic/TeleopContinuous

Now, you probably want to put it in TeleopPeriodic(). If you put it in any ----Init() method, it will run it only once. Periodic methods run at a rate that's clocked to the FPGA, and continuous methods run as fast as possible. You want to put most of your code in periodic.