Program/Source Code:

The source code to add LinkedList collection to another LinkedList collection on the specified index is given below. The given program is compiled and executed successfully.

// Java program to add LinkedList collection into another LinkedList 
// collection on the specified index

import java.util.LinkedList;

public class Main {
  public static void main(String[] args) {
    LinkedList < String > countries = new LinkedList < String > ();
    LinkedList < String > country = new LinkedList < String > ();

    countries.add("India");
    countries.add("USA");
    countries.add("UK");
    countries.add("CANADA");

    country.add("PAKISTAN");
    country.add("SRI-LANKA");
    country.add("JAPAN");

    System.out.println("Country names: " + countries);

    countries.addAll(2, country);

    System.out.println("Country names: " + countries);
  }
}

Output:

Country names: [India, USA, UK, CANADA]
Country names: [India, USA, PAKISTAN, SRI-LANKA, JAPAN, UK, CANADA]

Explanation:

In the above program, we imported the "java.util.LinkedList" package to use the LinkedList collection class. Here, we created a class Main. The Main class contains a main() method. The main() method is the entry point for the program.

In the main() method, we created two objects of the LinkedList collection class to store country names. Here, we added country collection into countries collection at index two using the addAll() method and printed the updated collection.