Mi correggo, devi usare questo metodo qui:
codice:
setHorizontalScrollBarPolicy

public void setHorizontalScrollBarPolicy(int policy)

    Determines when the horizontal scrollbar appears in the scrollpane. The options are:

        * ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED
        * ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER
        * ScrollPaneConstants.HORIZONTAL_SCROLLBAR_ALWAYS 

    Parameters:
        policy - one of the three values listed above 
    Throws:
        IllegalArgumentException - if policy is not one of the legal values shown above
    See Also:
        getHorizontalScrollBarPolicy()
Credo ti serva ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER