java - 从 Java 中的嵌入式类调用方法

Question

给定 Account t，代码旨在启用 BankAccount 方法 getBalance 来调用 Account 实例中的字段 SavingAccount。我尝试了各种执行此方法的方法。
主要变化如下:

Account t = new Account();

吨

t.setSavingsAccount(new BankAccount());

银行账户@xxxxxx

t. SavingsAccount.getBalance();

静态错误:帐户中没有字段名称为“SavingsAccount”

我如何重写此代码，以便将 SavingAccount 视为一个字段？
有没有更好的方法在 t 中执行 getBalance 方法？

相关代码:

    /**
 * A class to track an individuals bank portfolio.
 */
public class Account extends Object{
  private BankAccount savingsAccount = null;              //savings account identification number

 /**
   * A method to set account holder's savings account identification number.
   * @param savings account identification number
   * @return savings account identification number
   */
  public BankAccount setSavingsAccount(BankAccount input){
    savingsAccount = input;
    return savingsAccount;
  }

     /**
      * A method to return account holder's savingsaccount identification number.
      * @return savingsaccount identification number
      */
     public BankAccount getSavingsAccount(){
        return savingsAccount;
     }
    }

/**
 * A class to track the balance and terms of a bank account.
 */
public class BankAccount extends Object{
  private double currentBalance = 0;              //the balance of the account

 /**
  * Returns the balance of the account.
  * @param - void
  * @return the balance of the account
  */
  public double getBalance(){
    return currentBalance;
  }
    }

Answer 1

正确的语法是

System.out.println(t.getSavingsAccount().getBalance());