帮我用java实现下列需求 1.项目目标 (1)掌握集合框架包含的内容； (2)掌握ArrayList和LinkedList的使用； (3)掌握HashMap的使用； (4)掌握Iterator的使用； (5)掌握泛型集合的使用。 2.项目任务 请做一个公司职员薪水管理系统，要求完成如下功能：当有新员工时，将该员工加入到管理系统； (1)可以根据员工号，显示该员工的信息； (2)可以显示所有员工信息； (3)可以修改员工薪水 （4）当员工离职时，将该员工从管理系统中删除。

好的，以下是一个简单的实现。注意，这只是示例代码，实际使用时需要考虑更多的细节和边界情况。

import java.util.*;

public class EmployeeManagementSystem {
    private List<Employee> employees;
    private Map<Integer, Employee> employeeMap;

    public EmployeeManagementSystem() {
        employees = new ArrayList<>();
        employeeMap = new HashMap<>();
    }

    public void addEmployee(Employee employee) {
        employees.add(employee);
        employeeMap.put(employee.getEmployeeID(), employee);
    }

    public Employee getEmployee(int employeeID) {
        return employeeMap.get(employeeID);
    }

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

    public void updateSalary(int employeeID, double salary) {
        Employee employee = employeeMap.get(employeeID);
        if (employee != null) {
            employee.setSalary(salary);
        }
    }

    public void removeEmployee(int employeeID) {
        Employee employee = employeeMap.get(employeeID);
        if (employee != null) {
            employees.remove(employee);
            employeeMap.remove(employeeID);
        }
    }

    public static void main(String[] args) {
        EmployeeManagementSystem system = new EmployeeManagementSystem();

        // 添加员工
        Employee employee1 = new Employee(1, "张三", 5000);
        Employee employee2 = new Employee(2, "李四", 6000);
        system.addEmployee(employee1);
        system.addEmployee(employee2);

        // 显示所有员工信息
        List<Employee> allEmployees = system.getAllEmployees();
        for (Employee employee : allEmployees) {
            System.out.println(employee);
        }

        // 修改员工薪水
        system.updateSalary(1, 5500);
        System.out.println(system.getEmployee(1));

        // 删除员工
        system.removeEmployee(2);
        allEmployees = system.getAllEmployees();
        for (Employee employee : allEmployees) {
            System.out.println(employee);
        }
    }
}

class Employee {
    private int employeeID;
    private String name;
    private double salary;

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

    public int getEmployeeID() {
        return employeeID;
    }

    public String getName() {
        return name;
    }

    public double getSalary() {
        return salary;
    }

    public void setSalary(double salary) {
        this.salary = salary;
    }

    @Override
    public String toString() {
        return "员工ID：" + employeeID + "，姓名：" + name + "，薪水：" + salary;
    }
}