java - Java中的方法实现

Question

如何在给定问题中将输入添加到 HashSet。我主要是想使用Manager类中的addEmployee、removeEmployee、printEmployee方法，但是不知道在main方法中要写什么，以便调用Manager类的addEmployee、removeEmployee、printEmployee方法

public class EmployeeTest
{
   public static void main(String[] args) 
   {
      Manager mgr = new Manager(207, "Barbara Johnson", "054-12-2367", 109_501.36, "US Marketing");
      Employee e=new Employee(127, "Kyle Jenner", "023-42-5368", 123_243.90); // newly edited
      mgr.addEmployee(e); //newly edited
      mgr.printEmployee(e); //newly edited
      printEmployee(mgr);
   }
   public static void printEmployee(Employee emp) 
   {
      System.out.println(); 
      System.out.println("Employee id:         " + emp.getEmpId());
      System.out.println("Employee name:       " + emp.getName());
      System.out.println("Employee Soc Sec #:  " + emp.getSsn());
      System.out.println("Employee salary:     " + NumberFormat.getCurrencyInstance().format((double) emp.getSalary()));          
   }
}

public class Employee 
{
  private int Id;
  private String name;
  private String ssn;
  private double salary;
  public Employee(int Id, String name, String ssn, double salary)
  {
     this.Id = Id;
     this.name = name;
     this.ssn = ssn;
     this.salary = salary;
  }
  public int getEmpId() 
  {
     return Id;
  }
  public String getName() 
  {
     return name;
  }
  public String getSsn()
  {
     return ssn;
  }
  public double getSalary() 
  {
     return salary;
  }
  public void setName(String name) 
  {
     if (name != null && !name.equals("")) 
     {
         this.name = name;
     }
  }
  public void raiseSalary(double increase) 
  {
     if (increase > 0) 
     {
         salary += increase;

     }
  }
}

public class Manager extends Employee 
{
  private String dept;
  public Manager(int Id, String name, String ssn, double salary, String dept)
  {
     super(Id, name, ssn, salary);
     this.dept = dept;
  }
  **private Set<Employee> staff=new HashSet<>();**  //This is where I need help
  **public void addEmployee(Employee e)**  //This is where I need help
  {
     staff.add(e);
  }
  **public void removeEmployee(Employee e)**  //This is where I need help
  {
     staff.remove(e);
  }
  **public void printEmployee(Employee e)**  //This is where I need help
  {
     for (Employee emp: staff)
     {
        System.out.println("Name : "+getName()+" "+"ID : "+getEmpId());
     }
  }
  public String getDeptName()
  {
     return dept;
  }
}

程序输出

姓名:芭芭拉·约翰逊 ID:207//所需输出:- 姓名:凯尔·詹纳 ID:127

员工 ID:207

员工姓名:芭芭拉·约翰逊

员工社团编号:054-12-2367

员工工资:109,501.36卢比

在 Manager 上测试 raiseSalary 和 setName:

员工 ID:207

员工姓名:Barbara Johnson-Smythe

员工社团编号:054-12-2367

员工工资:119,501.36卢比

Answer 1

由于 printEmployee() 中 emp 的静态类型是 Employee，因此您只能使用 Employee 中定义的方法(或定义并在 Manager 中覆盖)。 由于 printEmployee() 是在 Manager 中定义的，因此只能在声明为 Manager

的变量中使用