FFT of 1D array of 1024 measurements

Hello Jeremy
Thank you for taking the time to respond!My knowledge of software is not great and I use the processing book to learn the language .I saw that there is FFT used in the sound library but I do not know how to adapt it for an array.Could you write a few lines how to do that?
I have no knowledge how to incorporate Java in processing.Any guidelines are also welcome and my knowledge of java is also limited.
Yours sincerely
Jozef Lodeweyckx
PS:The data for the array I get through Arduino .