Spatial Reference Conversion

I am currently having some problem with the spatial reference projection on the map in Android.

Basically I have a base map which is OneMap and all the coordinates stored in database is in SVY21 format. However, I wanted to display it using GoogleMap which is in WGS84 format. I wonder is there any ways for me to convert it in Java?

Because by using OneMap Api Documentation, it has a conversion method which is in JavaScript. However, I need it to be in Java for my Android project. Any ideas?