java - How to null check and return a value in a generic way

Question

I have a long list of object mapping to do from classes auto generated by JAXB.

 customer.setCustomerId(rentalCustomer.getCustomerid().getValue()));
 customer.setCustomerName(rentalCustomer.getTradingname().getValue());
 customer.setVatNumber(rentalSearchCustomer.getVatNumber().getValue());
 ....
 ....

Basically I need to make a null check for ALL fields:

getValue(RentalCustomerIDType idType){
  if(idType != null){
    return idType.getValue();
  }
  else {
   return "";
 }
}

Problem is there are too many of these and they all have different types: RentalCustomerIDType, TradingType, VatNumberType..etc

Is there an elegant way to this by creating a GENERIC method that makes null check and return proper values for ALL maybe using Functional Libraries for Java?

Answer 1

Perhaps use reflection on the class when it's generated and eliminate all nulls by assigning non-null values to the fields?

Check an replace null values in multiple variables java

They say (the guy who answered) that they strongly disagree with using reflection for this purpose... but... meh. I've done it and it works.