java银行存取款系统

好的，银行存取款系统是一个比较复杂的系统，需要设计多个类来实现不同的功能。这里给出一个简单的示例代码，帮助你了解如何实现一个基本的银行存取款系统。

首先，我们需要定义一个银行账户类（Account），用于记录用户的账户信息、余额和交易记录等。

public class Account {
    private String accountNumber;    // 账号
    private String accountName;      // 账户名
    private double balance;          // 余额
    private List<Transaction> transactions;  // 交易记录

    public Account(String accountNumber, String accountName, double balance) {
        this.accountNumber = accountNumber;
        this.accountName = accountName;
        this.balance = balance;
        this.transactions = new ArrayList<>();
    }

    public String getAccountNumber() {
        return accountNumber;
    }

    public String getAccountName() {
        return accountName;
    }

    public double getBalance() {
        return balance;
    }

    public void deposit(double amount) {
        balance += amount;
        transactions.add(new Transaction(TransactionType.DEPOSIT, amount));
    }

    public void withdraw(double amount) {
        if (balance < amount) {
            throw new IllegalArgumentException("余额不足");
        }
        balance -= amount;
        transactions.add(new Transaction(TransactionType.WITHDRAW, amount));
    }

    public List<Transaction> getTransactions() {
        return transactions;
    }

    public enum TransactionType {
        DEPOSIT,
        WITHDRAW
    }

    public static class Transaction {
        private TransactionType type;
        private double amount;

        public Transaction(TransactionType type, double amount) {
            this.type = type;
            this.amount = amount;
        }

        public TransactionType getType() {
            return type;
        }

        public double getAmount() {
            return amount;
        }
    }
}

接下来，我们需要定义一个银行类（Bank），用于管理所有的账户，并提供存取款等操作。

public class Bank {
    private Map<String, Account> accounts;  // 所有账户

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

    public void addAccount(Account account) {
        accounts.put(account.getAccountNumber(), account);
    }

    public Account getAccount(String accountNumber) {
        return accounts.get(accountNumber);
    }

    public void deposit(String accountNumber, double amount) {
        Account account = getAccount(accountNumber);
        if (account == null) {
            throw new IllegalArgumentException("账户不存在");
        }
        account.deposit(amount);
    }

    public void withdraw(String accountNumber, double amount) {
        Account account = getAccount(accountNumber);
        if (account == null) {
            throw new IllegalArgumentException("账户不存在");
        }
        account.withdraw(amount);
    }

    public List<Account> getAllAccounts() {
        return new ArrayList<>(accounts.values());
    }
}

最后，我们可以编写一个测试类（TestBank），用于演示如何使用银行类实现存取款操作。

public class TestBank {
    public static void main(String[] args) {
        Bank bank = new Bank();

        Account account1 = new Account("1001", "张三", 1000);
        Account account2 = new Account("1002", "李四", 2000);

        bank.addAccount(account1);
        bank.addAccount(account2);

        bank.deposit("1001", 500);
        bank.withdraw("1002", 1000);

        List<Account> accounts = bank.getAllAccounts();
        for (Account account : accounts) {
            System.out.println(account.getAccountNumber() + " " + account.getAccountName() + " " + account.getBalance());
            List<Account.Transaction> transactions = account.getTransactions();
            for (Account.Transaction transaction : transactions) {
                System.out.println(transaction.getType().name() + " " + transaction.getAmount());
            }
        }
    }
}

以上就是一个简单的银行存取款系统的实现。当然，实际的银行系统还需要考虑各种安全性、并发性等问题，这里仅提供一个基本的示例。