From BiblePortal Wikipedia

King James Dictionary [1]

Joy'Ful, a. Full of joy very glad exulting.

My soul shall be joyful in my God.  Isaiah 61

Rarely, it has of before the cause of joy.

Sad for their loss, but joyful of our life.

Webster's Dictionary [2]

(a.) Full of joy; having or causing joy; very glad; as, a joyful heart.