如何从java中的抽象类arraylist中打印特定的对象类型

How to print a specific object type from an abstract class arraylist in java

下面的课是我的主课。我的arraylist是"Employee"的类型，该arraylist包含许多具有多个对象(多态性)的元素。所以我想知道，当用户输入类名时，我应该从arraylist中打印出特定类的雇员。例如，当用户输入"外科医生"时，程序应该能够从数组列表中打印出所有外科医生员工的。请帮忙，提前谢谢。

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61

import java.util.*;

public class HospitalDatabase {

/**
* @param args the command line arguments
*/
public static void main(String[] args) {
String q;
String w;
ArrayList<Employee> e = new ArrayList<Employee>();
Employee s = new Surgeon("Christian Barnard", 2113211,"Cardiac","Cardiology",
2000,"Yale University");
Employee i = new ITSupport("Mickey Mouse", 11280, Department.IT, 26,"Mac OS");
Employee n = new Nurse("Florence Nightingale", 54678,"Urgent Care",
"Emergency", false, HospitalWing.North);
Employee p = new PatientAccountsManager("Donald Duck", 32465, Department.PatientSupport,
99, true);
Employee s1 = new Surgeon("Sanjay Gupta", 42171,"Neurosurgery",
"Neurology", 500,"Duke University");
Employee n1 = new Nurse("Mary Breckinridge", 56536,"Gynecology","Midwife",
true, HospitalWing.West);

e.add(s);
e.add(i);
e.add(n);
e.add(p);
e.add(s1);
e.add(n1);

System.out.println(e.toString());
System.out.println(Employee.numEmployees);
System.out.println("-------------******--------------");

Scanner scan = new Scanner(System.in);
System.out.println("Enter a name:");
q = scan.nextLine();
boolean j = false;
System.out.println("***************");

for(Employee v: e){
if(v.name.contains(q)){
System.out.println(v.name);
j = true;
}
}
if(j == false){
System.out.println("Name not found");
}
System.out.println("----------------**************---------------");

Scanner f = new Scanner(System.in);
System.out.println("Enter the class of employees:");
w = f.nextLine();
System.out.println("***************************");

//PLEASE SHOW THE CODE HERE
}
}