1.实现程序模拟简单的企业职工管理系统。编写程序实现以下要求： （1）请按继承层次构建企业的各种职工类型，包括超类Employee，以及相应的子类 Manager、Secretary和Programmer，从Manager继承又可得到Executive。超类 Employee有编号，姓名，年龄，薪金、地址和雇佣日期等信息。 （2）用户可以根据职工编号或职工姓名查找所需的信息。管理人员可以增加，删除数据；可以 写入一个数据，查找一个数据，或删除一个数据；此外，管理人员可以增加或降低每个职工的薪 金。程序通过ArrayList来实现增加，查找，删除数据

好的，这是一个比较复杂的程序，需要用到继承、ArrayList 等知识。以下是代码示例：

Employee.java

import java.util.Date;

public class Employee {
    private String id;
    private String name;
    private int age;
    private double salary;
    private String address;
    private Date hireDate;

    public Employee(String id, String name, int age, double salary, String address, Date hireDate) {
        this.id = id;
        this.name = name;
        this.age = age;
        this.salary = salary;
        this.address = address;
        this.hireDate = hireDate;
    }

    public String getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public double getSalary() {
        return salary;
    }

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

    public String getAddress() {
        return address;
    }

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

    public Date getHireDate() {
        return hireDate;
    }

    public void setHireDate(Date hireDate) {
        this.hireDate = hireDate;
    }

    @Override
    public String toString() {
        return "Id: " + id + ", Name: " + name + ", Age: " + age + ", Salary: " + salary + ", Address: " + address
                + ", HireDate: " + hireDate.toString();
    }
}

Manager.java

public class Manager extends Employee {
    public Manager(String id, String name, int age, double salary, String address, Date hireDate) {
        super(id, name, age, salary, address, hireDate);
    }

    public void promote(double raise) {
        this.setSalary(this.getSalary() + raise);
    }

    public void demote(double decrease) {
        this.setSalary(this.getSalary() - decrease);
    }
}

Secretary.java

public class Secretary extends Employee {
    public Secretary(String id, String name, int age, double salary, String address, Date hireDate) {
        super(id, name, age, salary, address, hireDate);
    }
}

Programmer.java

public class Programmer extends Employee {
    public Programmer(String id, String name, int age, double salary, String address, Date hireDate) {
        super(id, name, age, salary, address, hireDate);
    }
}

Executive.java

public class Executive extends Manager {
    public Executive(String id, String name, int age, double salary, String address, Date hireDate) {
        super(id, name, age, salary, address, hireDate);
    }
}

EmployeeManagementSystem.java

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.Scanner;

public class EmployeeManagementSystem {
    private ArrayList<Employee> employees = new ArrayList<>();
    private SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");

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

    public void removeEmployee(Employee employee) {
        employees.remove(employee);
    }

    public void printEmployee(Employee employee) {
        System.out.println(employee.toString());
    }

    public Employee findEmployeeById(String id) {
        for (Employee employee : employees) {
            if (employee.getId().equals(id)) {
                return employee;
            }
        }
        return null;
    }

    public ArrayList<Employee> findEmployeesByName(String name) {
        ArrayList<Employee> foundEmployees = new ArrayList<>();
        for (Employee employee : employees) {
            if (employee.getName().equals(name)) {
                foundEmployees.add(employee);
            }
        }
        return foundEmployees;
    }

    public void promoteManager(Manager manager, double raise) {
        manager.promote(raise);
    }

    public void demoteManager(Manager manager, double decrease) {
        manager.demote(decrease);
    }

    public static void main(String[] args) throws ParseException {
        EmployeeManagementSystem system = new EmployeeManagementSystem();
        Scanner scanner = new Scanner(System.in);

        // 添加一些员工
        system.addEmployee(new Manager("1", "Tom", 30, 5000, "Shanghai", system.dateFormat.parse("2020-01-01")));
        system.addEmployee(new Secretary("2", "Jerry", 25, 3000, "Beijing", system.dateFormat.parse("2020-02-01")));
        system.addEmployee(new Programmer("3", "Jack", 28, 4000, "Guangzhou", system.dateFormat.parse("2020-03-01")));
        system.addEmployee(new Executive("4", "Rose", 35, 8000, "Shenzhen", system.dateFormat.parse("2020-04-01")));

        while (true) {
            System.out.println("1. Add employee");
            System.out.println("2. Remove employee");
            System.out.println("3. Find employee by ID");
            System.out.println("4. Find employees by name");
            System.out.println("5. Promote manager");
            System.out.println("6. Demote manager");
            System.out.println("7. Print employee information");
            System.out.println("8. Exit");
            System.out.print("Please enter your choice: ");
            int choice = scanner.nextInt();
            scanner.nextLine(); // 读取换行符

            switch (choice) {
            case 1:
                System.out.print("Please enter ID: ");
                String id = scanner.nextLine();
                System.out.print("Please enter name: ");
                String name = scanner.nextLine();
                System.out.print("Please enter age: ");
                int age = scanner.nextInt();
                scanner.nextLine(); // 读取换行符
                System.out.print("Please enter salary: ");
                double salary = scanner.nextDouble();
                scanner.nextLine(); // 读取换行符
                System.out.print("Please enter address: ");
                String address = scanner.nextLine();
                System.out.print("Please enter hire date (yyyy-MM-dd): ");
                Date hireDate = system.dateFormat.parse(scanner.nextLine());

                System.out.println("Please select employee type:");
                System.out.println("1. Manager");
                System.out.println("2. Secretary");
                System.out.println("3. Programmer");
                int typeChoice = scanner.nextInt();
                scanner.nextLine(); // 读取换行符

                Employee employee = null;
                switch (typeChoice) {
                case 1:
                    employee = new Manager(id, name, age, salary, address, hireDate);
                    break;
                case 2:
                    employee = new Secretary(id, name, age, salary, address, hireDate);
                    break;
                case 3:
                    employee = new Programmer(id, name, age, salary, address, hireDate);
                    break;
                default:
                    System.out.println("Invalid employee type!");
                    break;
                }

                if (employee != null) {
                    system.addEmployee(employee);
                    System.out.println("Employee added!");
                }
                break;
            case 2:
                System.out.print("Please enter ID of the employee to remove: ");
                String removeId = scanner.nextLine();
                Employee removeEmployee = system.findEmployeeById(removeId);
                if (removeEmployee != null) {
                    system.removeEmployee(removeEmployee);
                    System.out.println("Employee removed!");
                } else {
                    System.out.println("Employee not found!");
                }
                break;
            case 3:
                System.out.print("Please enter ID of the employee to find: ");
                String findId = scanner.nextLine();
                Employee findEmployee = system.findEmployeeById(findId);
                if (findEmployee != null) {
                    system.printEmployee(findEmployee);
                } else {
                    System.out.println("Employee not found!");
                }
                break;
            case 4:
                System.out.print("Please enter name of the employee to find: ");
                String findName = scanner.nextLine();
                ArrayList<Employee> foundEmployees = system.findEmployeesByName(findName);
                if (foundEmployees.size() > 0) {
                    for (Employee employee : foundEmployees) {
                        system.printEmployee(employee);
                    }
                } else {
                    System.out.println("Employee not found!");
                }
                break;
            case 5:
                System.out.print("Please enter ID of the manager to promote: ");
                String promoteId = scanner.nextLine();
                Manager promoteManager = (Manager) system.findEmployeeById(promoteId);
                if (promoteManager != null) {
                    System.out.print("Please enter raise amount: ");
                    double raise = scanner.nextDouble();
                    scanner.nextLine(); // 读取换行符
                    system.promoteManager(promoteManager, raise);
                    System.out.println("Manager promoted!");
                } else {
                    System.out.println("Manager not found!");
                }
                break;
            case 6:
                System.out.print("Please enter ID of the manager to demote: ");
                String demoteId = scanner.nextLine();
                Manager demoteManager = (Manager) system.findEmployeeById(demoteId);
                if (demoteManager != null) {
                    System.out.print("Please enter decrease amount: ");
                    double decrease = scanner.nextDouble();
                    scanner.nextLine(); // 读取换行符
                    system.demoteManager(demoteManager, decrease);
                    System.out.println("Manager demoted!");
                } else {
                    System.out.println("Manager not found!");
                }
                break;
            case 7:
                System.out.print("Please enter ID of the employee to print: ");
                String printId = scanner.nextLine();
                Employee printEmployee = system.findEmployeeById(printId);
                if (printEmployee != null) {
                    system.printEmployee(printEmployee);
                } else {
                    System.out.println("Employee not found!");
                }
                break;
            case 8:
                System.out.println("Goodbye!");
                System.exit(0);
                break;
            default:
                System.out.println("Invalid choice!");
                break;
            }

            System.out.println();
        }
    }
}

这个程序实现了一个简单的企业职工管理系统，可以添加、删除、查找、升职、降职、打印员工信息等操作。用户可以通过输入数字选择操作。程序使用了 ArrayList 来存储员工信息。