This snippet represents the composite design pattern

CategoryDramaMoviesFolder.java

public class CategoryDramaMoviesFolder implements FolderDetailsComponent {
    @Override
    public void printFolderDetails() {
        System.out.println("Folder Details: Category drama movies");
    }
}

GamesFolder.java

public class GamesFolder implements FolderDetailsComponent {
    @Override
    public void printFolderDetails() {
        System.out.println("Folder Details: Game's");
    }
}

JurassicParkMovie.java

public class JurassicParkMovie implements FolderDetailsComponent {
    @Override
    public void printFolderDetails() {
        System.out.println("File Details: Jurassic Park");
    }
}

MovieDemo.java

public class MovieDemo {

    public static void main(String[] args){
        // Parent
        ParentFolder parentFolder = new ParentFolder();
        // First level children
        SoftwaresFolder softFolder = new SoftwaresFolder();
        MoviesFolder moviesFolder = new MoviesFolder();
        GamesFolder gamesFolder = new GamesFolder();
        // Second level children
        JurassicParkMovie jurassicParkMovieFile = new JurassicParkMovie();
        CategoryDramaMoviesFolder categoryDramaMoviesFolder = new CategoryDramaMoviesFolder();
        // Add second level children
        moviesFolder.addItems(jurassicParkMovieFile);
        moviesFolder.addItems(categoryDramaMoviesFolder);
        // Add first level children
        parentFolder.add(softFolder);
        parentFolder.add(moviesFolder);
        parentFolder.add(gamesFolder);
        // Initiate print
        parentFolder.printFolderDetails();
    }

}

MoviesFolder.java

public class MoviesFolder implements FolderDetailsComponent {

    private ArrayList<FolderDetailsComponent> comp = new ArrayList<>();

    public void addItems(FolderDetailsComponent component) {
        comp.add(component);
    }

    @Override
    public void printFolderDetails() {

        System.out.println("Folder Details: Movie's");

        for(FolderDetailsComponent component : comp){
            component.printFolderDetails();
        }
    }
}

ParentFolder.java

public class ParentFolder implements FolderDetailsComponent {

    ArrayList<FolderDetailsComponent> comp = new ArrayList<>();

    public void add(FolderDetailsComponent component){
        comp.add(component);
    }

    @Override
    public void printFolderDetails() {
        System.out.println("Folder Details: Parent Folder");
        for (FolderDetailsComponent component: comp) {
            component.printFolderDetails();
        }
    }

}

SoftwaresFolder.java

public class SoftwaresFolder implements FolderDetailsComponent {
    @Override
    public void printFolderDetails() {
        System.out.println("Folder Details: Software's");
    }
}