Java – Getter patterns in classes?

I have a field in the class that can only be accessed directly from the getter. For example….

public class CustomerHelper {
  private final Integer customerId;
  private String customerName_ = null;

public CustomerHelper(Integer customerId) {
    this.customerId = customerId;
  }

public String getCustomerName() {
    if(customerName_ == null){
       Get data from database.
      customerName_ = customerDatabase.readCustomerNameFromId(customerId);
       Maybe do some additional post-processing, like casting to all uppercase.
      customerName_ = customerName_.toUpperCase();
    }
    return customerName_;
  }

public String getFormattedCustomerInfo() {
    return String.format("%s: %s", customerId, getCustomerName());
  }
}

Therefore, even inside the class itself, functions like getFormattedCustomerInfo should not be able to access it through customerName_. In addition to the provided getter function, is there a way to force the class not to access the field directly?

There is no such mechanism in Java (or at least I don’t think there should be). If you determine that getFormattedCustomerInfo should be prevented from accessing the customerName_ directly, create another class and combine them.

I would recommend CustomerInfoFormatter.

Also, I’ll change customerName_ to customerName because the language supports privacy by explicitly declaring and doesn’t need to add more indicators.