问为什么netbeans不在代码中显示系统输出

EN

package fitnessclassapp;
import java.util.Scanner;
public class BookingController {       

   private Scanner input = new Scanner (System.in); 
   Customer customer = new Customer (); 

    // customer enter details and the details are validated   
    private String Customer () { 

        String customerName = ""; 
        int customerAge = -1 ; 
        String  membership  = ""; 
        boolean isName; 

        System.out.println( "Please enter your name " );
        do { 
            // name of condition HasNext will check the user input 
            if ( input.hasNext()) { 
                customerName = input.nextLine();
                isName = true; 

                // add a boolean 
            }else
                System.out.println ( "You have provided incorrect information");

            isName = false; 
            input.next(); 

        }while ( !isName ); 

        System.out.println(customerName); 

        return customerName; 
    }   
}