ObjectUsage.java

//What I'm trying to work out stylistically is that is it a code smell to do something like, calling into an object heirachy
//Like this => this.setFirstName(order.getCustomer().getFirstName());
//The "ORDER" creates a "CUSTOMER", the "CUSTOMER" has properties that the order calls down into

public class Usage {
  public OrderResponse createOrder(CustomerOrder order) {
    
    OrderProcessor processor = new OrderProcessor();
    
    CustomerOrderPayload customerOrderPayload = new CustomerOrderPayload() {{
            this.setFirstName(order.getCustomer().getFirstName());
            this.setLastName(order.getCustomer().getLastName());
        }};

        Order order = new Order() {{
            this.setProductList(createOrderList(customerOrderPayload, order));
        }}; 
    
    return processor.processOrder(customerOrderPayload, order);
    
  }
}

public class CustomerOrderPayload {
  private Customer customer;
  
  public void setCustomer(Customer customer) {
    this.customer = customer; 
  }
  
  public Customer getCustomer() {
    return this.customer; 
  }
}

public class Customer {
  private String firstName;
  private String lastName;
  
  public void setFirstName(String firstName) {
    this.firstName = firstName; 
  }
  
  public void setLastName(String lastName) {
    this.lastName = lastName; 
  }
  
  public String getFirstName() {
    return this.firstName; 
  }
  
  public String getLastName() {
    return this.lastName; 
  }
} 

Line 10:

		CustomerOrderPayload customerOrderPayload = new CustomerOrderPayload()
		{{
			this.setCustomer(order.getCustomer());
		}};

Just set the customer and then in the setCustomer() method set the properties...

How about this?

public class Usage {
public OrderResponse createOrder(CustomerOrder order) {

OrderProcessor processor = new OrderProcessor();

Customer customer = new Customer();
    customer
        .setFirstName("Steve")
        .setLastName("Smith)
        .build();

CustomerOrderPayload customerOrderPayload = new CustomerOrderPayload();
    customerOrderPayload
        .setCustomer(customer)
        .build();

ProductList productList = new ProductList();
    productList.setItem("item")
        .setItem("item)
        .build();

Order order = new Order();
    order.setProductList(productList);
        .build();
        
CustomerOrderPayload customerOrderPayload = new CustomerOrderPayload(customerOrderPayload);
return processor.processOrder(customerOrderPayload, order);

}
}

From your original comment you mean.

Customer customer = new Customer();
customer.setFirstName("Steve");

CustomerOrderPayload customerOrderPayload = new CustomerOrderPayload()
{{
this.setCustomer(customer);
}};

?

From your original comment you mean.

Customer customer = new Customer();
customer.setFirstName("Steve");

CustomerOrderPayload customerOrderPayload = new CustomerOrderPayload()
{{
this.setCustomer(customer);
}};

?

Yup