java的客户管理系统（用jdbc技术，进行控制台输出的客户管理系统，并写出全部步骤和代码以及用三层架构提现其项目功能）

好的，下面是Java客户管理系统的全部步骤和代码，同时使用三层架构提现其项目功能。

步骤：

1. 创建Java项目，并建立数据库连接。这里使用MySQL数据库，所以需要引入MySQL驱动程序。

2. 创建表示层。在控制台上输出欢迎信息以及菜单选项。用户可以选择添加客户、删除客户、修改客户、查询客户或者退出系统。

3. 创建数据访问层。使用JDBC技术与MySQL数据库进行交互。在这里，我们需要实现向数据库中插入一条新记录、从数据库中删除相应的记录、更新数据库中的记录以及从数据库中查询记录等操作。

4. 创建业务逻辑层。客户管理类用于实现与客户相关的操作。该类应该包括添加客户、删除客户、更新客户、查询客户等方法。

5. 在表示层中调用客户管理类的相应方法，以执行用户选择的操作。

代码：

表示层：

package com.example;

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        System.out.println("Welcome to the Customer Management System!");
        Scanner scanner = new Scanner(System.in);
        CustomerManager manager = new CustomerManager();
        while (true) {
            System.out.println("Please select an option:");
            System.out.println("1. Add a customer");
            System.out.println("2. Delete a customer");
            System.out.println("3. Update a customer");
            System.out.println("4. Query customers");
            System.out.println("5. Exit");
            int choice = scanner.nextInt();
            switch (choice) {
                case 1:
                    manager.addCustomer();
                    break;
                case 2:
                    manager.deleteCustomer();
                    break;
                case 3:
                    manager.updateCustomer();
                    break;
                case 4:
                    manager.queryCustomers();
                    break;
                case 5:
                    System.out.println("Thank you for using the Customer Management System.");
                    System.exit(0);
                    break;
                default:
                    System.out.println("Invalid input. Please try again.");
                    break;
            }
        }
    }
}

数据访问层：

package com.example;

import java.sql.*;

public class CustomerDAO {
    private static final String URL = "jdbc:mysql://localhost:3306/customer_management_system";
    private static final String USERNAME = "root";
    private static final String PASSWORD = "password";
    private Connection connection;
    private PreparedStatement statement;

    public CustomerDAO() {
        try {
            connection = DriverManager.getConnection(URL, USERNAME, PASSWORD);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public void addCustomer(Customer customer) {
        try {
            String sql = "INSERT INTO customers (name, phone, address) VALUES (?, ?, ?)";
            statement = connection.prepareStatement(sql);
            statement.setString(1, customer.getName());
            statement.setString(2, customer.getPhone());
            statement.setString(3, customer.getAddress());
            int result = statement.executeUpdate();
            if (result > 0) {
                System.out.println("Customer added successfully.");
            } else {
                System.out.println("Failed to add customer.");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public void deleteCustomer(int id) {
        try {
            String sql = "DELETE FROM customers WHERE id=?";
            statement = connection.prepareStatement(sql);
            statement.setInt(1, id);
            int result = statement.executeUpdate();
            if (result > 0) {
                System.out.println("Customer deleted successfully.");
            } else {
                System.out.println("Failed to delete customer.");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public void updateCustomer(Customer customer) {
        try {
            String sql = "UPDATE customers SET name=?, phone=?, address=? WHERE id=?";
            statement = connection.prepareStatement(sql);
            statement.setString(1, customer.getName());
            statement.setString(2, customer.getPhone());
            statement.setString(3, customer.getAddress());
            statement.setInt(4, customer.getId());
            int result = statement.executeUpdate();
            if (result > 0) {
                System.out.println("Customer updated successfully.");
            } else {
                System.out.println("Failed to update customer.");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    public void queryCustomers() {
        try {
            String sql = "SELECT * FROM customers";
            statement = connection.prepareStatement(sql);
            ResultSet resultSet = statement.executeQuery();
            while (resultSet.next()) {
                int id = resultSet.getInt("id");
                String name = resultSet.getString("name");
                String phone = resultSet.getString("phone");
                String address = resultSet.getString("address");
                System.out.println("ID: " + id + ", Name: " + name + ", Phone: " + phone + ", Address: " + address);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

业务逻辑层：

package com.example;

import java.util.Scanner;

public class CustomerManager {
    private CustomerDAO dao;
    private Scanner scanner;

    public CustomerManager() {
        dao = new CustomerDAO();
        scanner = new Scanner(System.in);
    }

    public void addCustomer() {
        System.out.println("Please enter the customer's name:");
        String name = scanner.next();
        System.out.println("Please enter the customer's phone number:");
        String phone = scanner.next();
        System.out.println("Please enter the customer's address:");
        String address = scanner.next();
        Customer customer = new Customer(name, phone, address);
        dao.addCustomer(customer);
    }

    public void deleteCustomer() {
        System.out.println("Please enter the ID of the customer you want to delete:");
        int id = scanner.nextInt();
        dao.deleteCustomer(id);
    }

    public void updateCustomer() {
        System.out.println("Please enter the ID of the customer you want to update:");
        int id = scanner.nextInt();
        System.out.println("Please enter the customer's new name:");
        String name = scanner.next();
        System.out.println("Please enter the customer's new phone number:");
        String phone = scanner.next();
        System.out.println("Please enter the customer's new address:");
        String address = scanner.next();
        Customer customer = new Customer(id, name, phone, address);
        dao.updateCustomer(customer);
    }

    public void queryCustomers() {
        dao.queryCustomers();
    }
}

客户类：

package com.example;

public class Customer {
    private int id;
    private String name;
    private String phone;
    private String address;

    public Customer(String name, String phone, String address) {
        this.name = name;
        this.phone = phone;
        this.address = address;
    }

    public Customer(int id, String name, String phone, String address) {
        this.id = id;
        this.name = name;
        this.phone = phone;
        this.address = address;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }
}

通过使用三层架构，Java客户管理系统实现了代码的模块化和可维护性。每个层次都有特定的职责，以实现代码的分离和重用。