checkingaccount.java

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package bank.v12;

/**
 * 支票帐户
 * 
 * @author oyotong
 * 
 */
public class CheckingAccount extends Account {

	private double overdraft;// 透支额度

	/**
	 * 提供支票帐户开户
	 * 
	 * @param balance
	 *            初始额度
	 * @param overdraft
	 *            透支额度
	 * @throws OpenAccountException 
	 */
	public CheckingAccount(double balance, double overdraft) throws OpenAccountException {
		super(balance);
		if(overdraft < 0){
			throw new OpenAccountException("透支额度不能为负数！");
		}
		this.overdraft = overdraft;
	}

	/**
	 * 覆盖父类方法,提供透支保护
	 * 
	 * @see bank.Account#deposit(double)
	 */
	public double withdraw(double out) throws OverDraftException {
		if (out > overdraft + balance) {

			// throw new OverDraftException("警告:你的余额不够!");

			System.out.println("警告:你的余额不够!");

			return balance;
		}
		// 调用父类方法
		balance -= out;
		System.out.println("提示:取钱操作成功.");
		return balance;
	}
}