Convert to JSON Java Script

I am working on Java JSP and JavaScript, and I need to convert the result of a DataStore query format:

<Entity [Usuario(5523854313120)]:
    Email = [email protected]
    PrimerNombre = Andres
    Rol = Administrador
   Password = andres125
>

to JSON format:

{"Email ":"[email protected]","PrimerNombre ":"Andres","Rol ":"Administrador", "Password":"andres125"}

This is the code:

DatastoreService datastore = DatastoreServiceFactory.getDatastoreService();
Query q=new Query("Usuario");
PreparedQuery pq = datastore.prepare(q);
Entity result=pq.asSingleEntity();