title: On the fly calculation of Fourier transformation in Java
body: <p>I want to write a program in Java that uses fast Fourier transformation.
  The program reads data every 5 milliseconds seconds from sensors and is supposed to do something with the data every 200 milliseconds based on the data from the last five seconds.</p>
  
  <p>Is there a good library in Java that provides a way to do Fourier transformation without recalculating all five seconds every time?</p>