Week 7: Enum, Generic Type, Streams, write to file, class diagram/04B. Generic Duplicator

Write a 'generically type-defined class'

Duplicator<T>

The class should have the following properties:
1
A constructor that takes an element of type T as a parameter.
2
Set and get methods for the element (getElement and setElement).
3
A method ArrayList<T> getMany(int amount), which returns a new list. 
The size of the list is the integer given as a parameter, and each element of the list is the element stored in the object.


An example of utilizing the class:

public static void main(String[] args) {
    Duplicator<String> d1 = new Duplicator<>("abc");
    System.out.println(d1.getMany(3));
    
    Duplicator<Double> d2 = new Duplicator<>(2.5);
    System.out.println(d2.getMany(4));
}




The program prints:
[abc, abc, abc]
[2.5, 2.5, 2.5, 2.5]










import java.util.Random;
import java.util.ArrayList;

public class Test {
    public static void main(String[] args) {
        final Random r = new Random();
        
        System.out.println("Testing the Duplicator class...");

        System.out.println("Testing with integer type...");
        int element = r.nextInt(100) + 1;
        System.out.println("Element value: " + element);
        Duplicator<Integer> d1 = new Duplicator<>(element);
        System.out.println("Object created!");

        System.out.println("getElement returns " + d1.getElement());
        element = r.nextInt(100) + 1;
        System.out.println("Calling setElement with value " + element);
        d1.setElement(element);
        System.out.println("getElement returns " + d1.getElement());

        int size = r.nextInt(6) + 2;
        System.out.println("Calling getMany with value " + size);
        ArrayList<Integer> al = d1.getMany(size);
        System.out.println(al);

        System.out.println("");

        System.out.println("Testing with string type...");
        String[] s = "dog cat guinea pig hamster cow sheep chicken guinea pig".split(" ");
        String sElement = s[r.nextInt(s.length)];
        System.out.println("Element value: " + sElement);
        Duplicator<String> d2 = new Duplicator<>(sElement);
        System.out.println("Object created!");

        System.out.println("getElement returns " + d2.getElement());
        sElement = s[r.nextInt(s.length)];
        System.out.println("Calling setElement with value " + sElement);
        d2.setElement(sElement);
        System.out.println("getElement returns " + d2.getElement());

        size = r.nextInt(6) + 2;
        System.out.println("Calling getMany with value " + size);
        ArrayList<String> al2 = d2.getMany(size);
        System.out.println(al2);        
    }
}





//ADD
class Duplicator<T> {
    // attribute
    private T singleInput;

    // constructor
    public Duplicator(T singleInput){
        this.singleInput = singleInput;
    }

    // get, set
    public T getElement() {
        return this.singleInput;
    }

    public void setElement(T singleInput) {
        this.singleInput = singleInput;
    }

    // duplicate this.singleInput
    // by 'amount' times
    // in the ArrayList
    public ArrayList<T> getMany(int amount) {
        ArrayList<T> list = new ArrayList<>();
        for (int i=0; i<amount; i++) {
            list.add(this.singleInput);
        }
        
        return list;
    }
}







Testing the Duplicator class...
Testing with integer type...
Element value: 94
Object created!
getElement returns 94
Calling setElement with value 27
getElement returns 27
Calling getMany with value 4
[27, 27, 27, 27]



Testing with string type...
Element value: sheep
Object created!
getElement returns sheep
Calling setElement with value guinea
getElement returns guinea
Calling getMany with value 2
[guinea, guinea]