prototypeRegistory

import java.util.*;

enum PageType{
    A4,
    A3,
    A5
}
//----------------------------
class NoteBook{
    private PageType pageType; //attributes
    private int pageCount;
    
    public void print(){
        System.out.println(pageType+" "+pageCount);
    }
    
    private NoteBook(){} //private constructor for building with params
    
    public NoteBook(PageType pageType, int pageCount){ 
        this.pageType = pageType;
        this.pageCount = pageCount;
    }
    
    public NoteBook clone(){ //copy this object to another
        NoteBook notebook = new NoteBook();
        notebook.pageType = this.pageType;
        notebook.pageCount = this.pageCount;
        return notebook;
    }
}
//-------------------------------
class NoteBookRegistory{
    private Map<String,NoteBook> notebooks = new HashMap<>();
    
    void registerNotebooks(String type, NoteBook notebook){ //store the notebook object in map.
        notebooks.put(type,notebook);
    }
    NoteBook getNotebook(String type){
        return notebooks.get(type).clone(); //return the clone of current notebook object present in map
    }
}
//---------------------------------
public class Client{
    public static void main(String[] args){
        //make first original objects
        NoteBook n1 = new NoteBook(PageType.A4, 50);
        NoteBook n2 = new NoteBook(PageType.A3, 50);
        NoteBook n3 = new NoteBook(PageType.A5, 50);
        
        //put these original objects in registory
        NoteBookRegistory registory = new NoteBookRegistory();
        registory.registerNotebooks("A4_50",n1);
        registory.registerNotebooks("A3_50",n2);
        registory.registerNotebooks("A5_50",n3);
        
        //Make a list of inputs you want prototype of.
        List<String> inputs = new ArrayList<>();
        inputs.add("A4_50");
        inputs.add("A4_50");
        inputs.add("A3_50");
        inputs.add("A5_50");
        inputs.add("A5_50");
        inputs.add("A5_50");
        
        //loop the input and make notebooks for each input
        List<NoteBook> notebooks = new ArrayList<>();
        for(String input : inputs){
            notebooks.add(registory.getNotebook(input));
        }
        
        //print all notebooks
        for(NoteBook notebook : notebooks){
            notebook.print();
        }
    }
}