在Java中管理Employee數據，首先需要創建一個Employee類，用于存儲和管理員工的信息

1. 創建Employee類：

public class Employee {
    private int id;
    private String name;
    private String position;
    private double salary;

    public Employee(int id, String name, String position, double salary) {
        this.id = id;
        this.name = name;
        this.position = position;
        this.salary = salary;
    }

    // Getter and Setter methods for id, name, position, and salary
}

2. 創建EmployeeManager類，用于管理Employee對象：

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

public class EmployeeManager {
    private List<Employee> employees;

    public EmployeeManager() {
        employees = new ArrayList<>();
    }

    public void addEmployee(Employee employee) {
        employees.add(employee);
    }

    public void removeEmployee(int id) {
        employees.removeIf(employee -> employee.getId() == id);
    }

    public Employee getEmployeeById(int id) {
        return employees.stream().filter(employee -> employee.getId() == id).findFirst().orElse(null);
    }

    public List<Employee> getAllEmployees() {
        return employees;
    }

    public void updateEmployeeSalary(int id, double newSalary) {
        Employee employee = getEmployeeById(id);
        if (employee != null) {
            employee.setSalary(newSalary);
        }
    }
}

3. 使用EmployeeManager類來管理Employee數據：

public class Main {
    public static void main(String[] args) {
        EmployeeManager manager = new EmployeeManager();

        // 添加員工
        manager.addEmployee(new Employee(1, "Alice", "Software Engineer", 80000));
        manager.addEmployee(new Employee(2, "Bob", "Data Analyst", 70000));

        // 獲取所有員工
        List<Employee> employees = manager.getAllEmployees();
        for (Employee employee : employees) {
            System.out.println(employee);
        }

        // 通過ID獲取員工
        Employee employee = manager.getEmployeeById(1);
        System.out.println("Employee with ID 1: " + employee);

        // 更新員工薪水
        manager.updateEmployeeSalary(1, 85000);
        System.out.println("Updated salary of Employee with ID 1: " + manager.getEmployeeById(1));

        // 刪除員工
        manager.removeEmployee(2);
        System.out.println("Remaining employees: " + manager.getAllEmployees());
    }
}

這個示例展示了如何使用Employee和EmployeeManager類來管理員工數據。你可以根據實際需求擴展這些類，添加更多屬性和方法。