Hands-On Design Patterns with Java

Programming the design pattern

The CreateBankAccount class includes a private constructor, which will prevent attempts to instantiate more than one instance of the CreateBankAccount object. The getNewAccount() method checks whether the newAccount already exists and provides contextual feedback to the user:

public class CreateBankAccount {    private static CreateBankAccount newAccount;    // constructor    private CreateBankAccount() {    }    public static CreateBankAccount getNewAccount() {        if (newAccount == null) {            newAccount = new CreateBankAccount();            System.out.println("New Account created.");        } else {            System.out.println("Account already opened.");        }        return newAccount;    }}

The Driver class, AccountDriver, prints a header label and then attempts to create ...