1887415156@qq.com

```java
package bank;

public class BankAccount {
    private String accountNumber;
    private String accountHolderName;
    private Date openingDate;
    private String idNumber;
    private double balance;

    public BankAccount(String accountNumber, String accountHolderName, Date openingDate, String idNumber, double balance) {
        this.accountNumber = accountNumber;
        this.accountHolderName = accountHolderName;
        this.openingDate = openingDate;
        this.idNumber = idNumber;
        this.balance = balance;
    }

    public void deposit(double amount) {
        balance += amount;
    }

    public boolean withdraw(double amount) {
        if (balance < amount) {
            return false; // insufficient funds
        }
        balance -= amount;
        return true;
    }

    public double getBalance() {
        return balance;
    }

    public void close() {
        accountNumber = null;
        accountHolderName = null;
        openingDate = null;
        idNumber = null;
        balance = 0;
    }

    @Override
    public void finalize() throws Throwable {
        super.finalize();
        System.out.println("账户 " + accountNumber + " 已关闭。");
        close();
    }
}
```
```