使用java代码模拟实现一个银行系统的部分功能，当客户在登录完成时，实现余额查询，转账功能，存取款，修改密码功能界面使用控制台实现，数据存储使用mysql数据库，Java操作数据库部分使用hutool工具类。

好的，以下是Java代码实现银行系统部分功能的示例：

首先，需要使用Hutool工具类连接MySQL数据库，代码如下：

import cn.hutool.db.Db;
import cn.hutool.db.Entity;
import cn.hutool.db.SqlRunner;

public class BankSystem {
    private static final String URL = "jdbc:mysql://localhost:3306/bank_system?useSSL=false&serverTimezone=UTC";
    private static final String USERNAME = "root";
    private static final String PASSWORD = "password";

    public static void main(String[] args) {
        // 连接数据库
        SqlRunner runner = Db.use().setRunner(new SqlRunner(URL, USERNAME, PASSWORD));
        // 其他操作...
    }
}

接着，需要实现用户的登录功能，这里假设用户的账号为手机号，密码为6位数字，代码如下：

import java.util.Scanner;

public class BankSystem {
    // ...
    private static final String TABLE_NAME = "user";
    
    public static void main(String[] args) {
        // 连接数据库
        SqlRunner runner = Db.use().setRunner(new SqlRunner(URL, USERNAME, PASSWORD));

        // 用户登录
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入手机号：");
        String phone = scanner.nextLine();
        System.out.println("请输入密码：");
        String password = scanner.nextLine();
        Entity user = runner.queryOne(String.format("SELECT * FROM %s WHERE phone = ? AND password = ?", TABLE_NAME), phone, password);
        if (user == null) {
            System.out.println("手机号或密码错误，登录失败。");
            return;
        }
        System.out.printf("欢迎，%s！%n", user.getStr("name"));

        // 其他操作...
    }
}

接下来，实现余额查询功能，代码如下：

public class BankSystem {
    // ...
    private static final String ACCOUNT_TABLE_NAME = "account";
    
    public static void main(String[] args) {
        // 连接数据库
        SqlRunner runner = Db.use().setRunner(new SqlRunner(URL, USERNAME, PASSWORD));

        // 用户登录...
        
        // 余额查询
        Entity account = runner.queryOne(String.format("SELECT * FROM %s WHERE user_id = ?", ACCOUNT_TABLE_NAME), user.getInt("id"));
        System.out.printf("您的账户余额为：%f元%n", account.getBigDecimal("balance"));

        // 其他操作...
    }
}

然后，实现转账功能，代码如下：

public class BankSystem {
    // ...
    
    public static void main(String[] args) {
        // 连接数据库
        SqlRunner runner = Db.use().setRunner(new SqlRunner(URL, USERNAME, PASSWORD));

        // 用户登录...

        // 转账
        System.out.println("请输入对方账号：");
        String toPhone = scanner.nextLine();
        Entity toUser = runner.queryOne(String.format("SELECT * FROM %s WHERE phone = ?", TABLE_NAME), toPhone);
        if (toUser == null) {
            System.out.println("对方账号不存在！");
            return;
        }
        Entity toAccount = runner.queryOne(String.format("SELECT * FROM %s WHERE user_id = ?", ACCOUNT_TABLE_NAME), toUser.getInt("id"));
        System.out.println("请输入转账金额：");
        double amount = scanner.nextDouble();
        if (amount <= 0) {
            System.out.println("转账金额必须大于0！");
            return;
        }
        Entity account = runner.queryOne(String.format("SELECT * FROM %s WHERE user_id = ?", ACCOUNT_TABLE_NAME), user.getInt("id"));
        if (account.getBigDecimal("balance").doubleValue() < amount) {
            System.out.println("余额不足！");
            return;
        }
        runner.tx(() -> {
            runner.update(String.format("UPDATE %s SET balance = balance - ? WHERE user_id = ?", ACCOUNT_TABLE_NAME), amount, user.getInt("id"));
            runner.update(String.format("UPDATE %s SET balance = balance + ? WHERE user_id = ?", ACCOUNT_TABLE_NAME), amount, toUser.getInt("id"));
            runner.insert("transfer_log", new Entity()
                    .set("from_user_id", user.getInt("id"))
                    .set("to_user_id", toUser.getInt("id"))
                    .set("amount", amount)
                    .set("time", System.currentTimeMillis()));
        });
        System.out.println("转账成功！");

        // 其他操作...
    }
}

接下来，实现存取款功能，代码如下：

public class BankSystem {
    // ...
    
    public static void main(String[] args) {
        // 连接数据库
        SqlRunner runner = Db.use().setRunner(new SqlRunner(URL, USERNAME, PASSWORD));

        // 用户登录...

        // 存取款
        Entity account = runner.queryOne(String.format("SELECT * FROM %s WHERE user_id = ?", ACCOUNT_TABLE_NAME), user.getInt("id"));
        System.out.printf("您的账户余额为：%f元%n", account.getBigDecimal("balance"));
        System.out.println("请选择操作类型：\n1. 存款\n2. 取款");
        int type = scanner.nextInt();
        if (type == 1) {
            System.out.println("请输入存款金额：");
            double amount = scanner.nextDouble();
            if (amount <= 0) {
                System.out.println("存款金额必须大于0！");
                return;
            }
            runner.update(String.format("UPDATE %s SET balance = balance + ? WHERE user_id = ?", ACCOUNT_TABLE_NAME), amount, user.getInt("id"));
            System.out.printf("存款成功！当前账户余额为：%f元%n", account.getBigDecimal("balance").add(new BigDecimal(amount)));
        } else if (type == 2) {
            System.out.println("请输入取款金额：");
            double amount = scanner.nextDouble();
            if (amount <= 0) {
                System.out.println("取款金额必须大于0！");
                return;
            }
            if (account.getBigDecimal("balance").doubleValue() < amount) {
                System.out.println("余额不足！");
                return;
            }
            runner.update(String.format("UPDATE %s SET balance = balance - ? WHERE user_id = ?", ACCOUNT_TABLE_NAME), amount, user.getInt("id"));
            System.out.printf("取款成功！当前账户余额为：%f元%n", account.getBigDecimal("balance").subtract(new BigDecimal(amount)));
        } else {
            System.out.println("无效操作！");
        }

        // 其他操作...
    }
}

最后，实现修改密码功能，代码如下：

public class BankSystem {
    // ...
    
    public static void main(String[] args) {
        // 连接数据库
        SqlRunner runner = Db.use().setRunner(new SqlRunner(URL, USERNAME, PASSWORD));

        // 用户登录...

        // 修改密码
        System.out.println("请输入旧密码：");
        String oldPassword = scanner.nextLine();
        if (!user.getStr("password").equals(oldPassword)) {
            System.out.println("旧密码错误！");
            return;
        }
        System.out.println("请输入新密码：");
        String newPassword = scanner.nextLine();
        runner.update(String.format("UPDATE %s SET password = ? WHERE id = ?", TABLE_NAME), newPassword, user.getInt("id"));
        System.out.println("密码修改成功！");

        // 其他操作...
    }
}

以上是Java代码实现银行系统部分功能的示例，希望能够帮到你。需要注意的是，这里只是简单地演示了如何实现功能，实际开发中还需要考虑很多问题，如异常处理、并发控制等。