title: Convert WGS84 lat/long to GGRS87
body: <p>Hello I am using <code>GMapsFX</code> for my JavaFX application. I am getting longtitude and latitute from <code>Google Maps</code> with the API but I would like to get <code>GGRS87</code> also.</p>
  <p>In Greek it is called <code>EGSA87</code>. Ι have searched for that and found nothing so far. There might be a solution on the libraries of <code>Geotools</code> or <code>proj4j</code> but I don't have very good knowledge of java and especially I can't find the solutions in so big libraries like those.</p>
  <p>I have found many sites to make calculations but how can I make a mathematical calculation myself? Or even a library to solve this problem?</p>