import java.util.ArrayList; import java.util.List; interface WebPageElement { String render(); } class Header implements WebPageElement { private String text; public Header(String text) { this.text = text; } @Override public String render() { return "

" + text + "

"; } } class Paragraph implements WebPageElement { private String text; public Paragraph(String text) { this.text = text; } @Override public String render() { return "

" + text + "

"; } } class ListElement implements WebPageElement { private List items; public ListElement(List items) { this.items = items; } @Override public String render() { StringBuilder itemsStr = new StringBuilder(); for (String item : items) { itemsStr.append("

").append(item).append("

"); } return "

" + itemsStr.toString() + ""; } } class WebPage { private String title; private List elements; public WebPage(String title) { this.title = title; this.elements = new ArrayList<>(); } public void addElement(WebPageElement element) { elements.add(element); } public String display() { StringBuilder elementsStr = new StringBuilder(); for (WebPageElement element : elements) { elementsStr.append(element.render()).append("\n"); } return "\n\n " + title + "\n\n\n\n " + elementsStr.toString() + "\n\n"; } } public class Main { public static void main(String[] args) { WebPage page = new WebPage("My Web Page"); page.addElement(new Header("Welcome to My Web Page")); page.addElement(new Paragraph("This is a paragraph of text on the web page.")); List items = new ArrayList<>(); items.add("Item 1"); items.add("Item 2"); items.add("Item 3"); page.addElement(new ListElement(items)); System.out.println(page.display()); /* Outputs: My Web Page

Welcome to My Web Page

This is a paragraph of text on the web page.

Item 1
Item 2
Item 3

*/ } }