library.java

import java.util.ArrayList;

abstract class LibraryItem
{
    private String itemID;
    private String title;
    protected boolean isReserved;

    LibraryItem(String id, String t)
    {
        itemID = id;
        title = t;
    }

    void showDetails()
    {
        System.out.println("Item Details:\n");
        System.out.println("Title: " + title);
        System.out.println("Item ID: " + itemID);
        System.out.println("Is Available: " + !isReserved);
    }

    String getTitle()
    {
        return title;
    }

    abstract void processLoan();
}

class Textbook extends LibraryItem
{
    Textbook(String id, String t)
    {
        super(id,t);
    }
    void processLoan()
    {
        if(isReserved == true)
        {
            System.out.println(getTitle()+ " Cannot be checked out!");
        }
        else
        {
            System.out.println("Hardcopy reserved for 14 days!");
            isReserved = true;
        }
    }
}


class ResearchPaper extends LibraryItem
{
    ResearchPaper(String id, String t)
    {
        super(id,t);
    }
    void processLoan()
    {
        System.out.println("Generating Secure pdf link...");
    }
}

public class library
{
    public static void main(String[] args) 
    {
        ArrayList<LibraryItem> L = new ArrayList<>();

        Textbook book = new Textbook("B101", "Java Core");
        L.add(book); 
        L.add(book);
        L.add(new ResearchPaper("R99", "AI Ethics"));

        for(int i = 0; i < L.size(); i++)
        {
            L.get(i).processLoan();
        }
    }
}