for(int i = 0; i < writers.length; i++){
Field f = fields[i];
Class<?> type = f.getType();
if(type == int.class){
writers[i] = new IntWriter(f);
}else if(type == Integer.class){
writers[i] = new NIntWriter(f);
}else if(type == Long.class){
writers[i] = new NBigIntWriter(f);
}else if(type == Boolean.class){