Java应用程序中实现交易历史记录的存储与管理

import java.time.LocalDateTime; // 导入用于获取当前时间的类

/**
 * 封装一笔交易的详细信息。
 */
public class TransactionRecord {
    private String sender;
    private String recipient;
    private int amount;
    private LocalDateTime timestamp;

    public TransactionRecord(String sender, String recipient, int amount) {
        this.sender = sender;
        this.recipient = recipient;
        this.amount = amount;
        this.timestamp = LocalDateTime.now(); // 记录交易发生时的当前时间
    }

    // Getter 方法，用于外部访问交易记录的属性
    public String getSender() {
        return sender;
    }

    public String getRecipient() {
        return recipient;
    }

    public int getAmount() {
        return amount;
    }

    public LocalDateTime getTimestamp() {
        return timestamp;
    }

    @Override
    public String toString() {
        return String.format("时间: %s, 转账人: %s, 接收人: %s, 金额: %d",
                             timestamp.format(java.time.format.DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss")),
                             sender, recipient, amount);
    }
}

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;

public class BankApp {
    private static int balance = 1000; // 示例账户余额
    private static Scanner scanner = new Scanner(System.in);
    // 声明一个List来存储交易历史记录
    private static List<TransactionRecord> transactionHistory = new ArrayList<>();

    public static String moneyTransfer(String currentUser) { // 假设currentUser是当前登录的用户
        System.out.println("请输入您要转账的账户名：");
        String recipientName = scanner.nextLine(); // 接收方账户名

        System.out.println("请输入要转账的金额给用户 " + recipientName + "：");
        int transferAmount = 0;
        try {
            transferAmount = scanner.nextInt();
        } catch (java.util.InputMismatchException e) {
            System.out.println("输入金额无效，请输入一个整数。");
            scanner.nextLine(); // 消耗掉错误的输入
            return "转账失败：金额输入错误。";
        } finally {
            scanner.nextLine(); // 消耗掉nextInt()留下的换行符，避免影响后续nextLine()
        }


        if (transferAmount <= 0) {
            System.out.println("转账金额必须大于零。");
            return "转账失败：金额无效。";
        }

        if (balance < transferAmount) {
            System.out.println("余额不足，无法完成转账。当前余额：" + balance);
            return "转账失败：余额不足。";
        }

        // 执行转账操作
        balance -= transferAmount;
        System.out.println("您成功转账 " + transferAmount + " 给用户: " + recipientName);
        System.out.println("当前余额: " + balance);

        // 创建并保存交易记录
        TransactionRecord record = new TransactionRecord(currentUser, recipientName, transferAmount);
        transactionHistory.add(record); // 将交易记录添加到历史列表中

        return "转账成功！";
    }

    /**
     * 显示所有交易历史记录。
     */
    public static void displayTransactionHistory() {
        if (transactionHistory.isEmpty()) {
            System.out.println("目前没有交易历史记录。");
            return;
        }
        System.out.println("\n--- 交易历史记录 ---");
        for (TransactionRecord record : transactionHistory) {
            System.out.println(record.toString());
        }
        System.out.println("--------------------");
    }

    public static void main(String[] args) {
        String currentUser = "用户A"; // 示例当前用户

        // 模拟几次转账操作
        System.out.println("欢迎来到银行应用！当前余额: " + balance);

        // 第一次转账
        System.out.println(moneyTransfer(currentUser));

        // 第二次转账
        System.out.println(moneyTransfer(currentUser));

        // 显示历史记录
        displayTransactionHistory();

        // 尝试一次失败的转账
        System.out.println(moneyTransfer(currentUser));

        // 再次显示历史记录，确认失败的转账不会被记录
        displayTransactionHistory();

        scanner.close();
    }
}