请给出一个用Java实现简单银行系统的例子。

原创短命女 2025-03-17 02:39 7阅读 0赞

以下是一个简单的银行系统用Java实现的例子，这个例子包括存款、取款和查询余额的功能：

```java
import java.util.HashMap;
import java.util.Map;

class BankAccount {
    private String accountNumber;
    private double balance;

BankAccount(String accountNumber) {
        this.accountNumber = accountNumber;
        this.balance = 0.0; // 初始化为0
    }

public void deposit(double amount) {
        if (amount > 0) {
            balance += amount;
        }
    }

public void withdraw(double amount) {
        if (amount >= 0 && balance >= amount) {
            balance -= amount;
        } else {
            System.out.println("Insufficient balance for withdrawal.");
        }
    }

public double getBalance() {
        return balance;
    }

@Override
    public String toString() {
        return "Account [accountNumber=" + accountNumber +
                ", balance=" + balance + "]";
    }
}

class BankSystem {
    private Map<String, BankAccount> accounts;

BankSystem() {
        this.accounts = new HashMap<>();
    }

public void openAccount(String accountNumber) {
        if (accountNumber != null && !accounts.containsKey(accountNumber)) {
            BankAccount account = new BankAccount(accountNumber);
            accounts.put(accountNumber, account);
            System.out.println("Account " + accountNumber + " opened successfully.");
        } else {
            System.out.println("Invalid account number. Account opening failed.");
        }
    }

public void deposit(String accountNumber, double amount) {
        if (accounts.containsKey(accountNumber))) {
            BankAccount account = accounts.get(accountNumber);
            account.deposit(amount);
            System.out.println("Amount " + amount + " successfully deposited into Account " + accountNumber + ".");
        } else {
            System.out.println("Account " + accountNumber + " does not exist. Deposit operation failed.");
        }
    }

public void withdraw(String accountNumber, double amount) {
        if (accounts.containsKey(accountNumber))) {
            BankAccount account = accounts.get(accountNumber);
            account.withdraw(amount);
            if (account.getBalance() >= 0 && account.getBalance() == amount) {
                System.out.println("Amount " + amount + " successfully withdrawn from Account " + accountNumber + ".");
            } else {
                System.out.println("Withdrawal of amount " + amount + " failed due to insufficient balance in Account " + accountNumber + ".");
            }
        } else {
            System.out.println("Account " + accountNumber + " does not exist. Withdrawal operation failed.");
        }
    }

public double getBalance(String accountNumber) {
        if (accounts.containsKey(accountNumber))) {
            return accounts.get(accountNumber)).getBalance();
        } else {
            System.out.println("Account " + accountNumber + " does not exist. Balance retrieval failed.");
            return -1; // 返回一个错误值，表示获取失败
        }
    }

public void closeAccount(String accountNumber) {
        if (accounts.containsKey(accountNumber))) {
            BankAccount account = accounts.get(accountNumber));
            accounts.remove(accountNumber);
            System.out.println("Account " + accountNumber + " successfully closed.");
        } else {
            System.out.println("Account " + accountNumber + " does not exist. Closing operation failed.");
        }
    }
}
```

这个例子中，`BankAccount`类表示银行账户，包含存款、取款和查询余额等功能。`BankSystem`类则管理多个账户，包括账户创建、存款、取款、查询余额以及关闭账户等操作。