관련 부품을 조합해서 인스턴스 생성

• 부품의 구체적인 구현에는 주목하지 않고, 인터페이스(API)에 주목.
• 추상적인 공장(Abstract Factory)에서 추상적인 부품을 조립하고 추상적인 제품을 완성한다.

package factory;

public abstract class Factory {
	public static Factory getFactory(String className) {
		Factory factory = null;
		
		try {
			factory = (Factory) Class.forName(className).newInstance();
		} catch (InstantiationException | IllegalAccessException | ClassNotFoundException e) {
			e.printStackTrace();
		}
		
		return factory;
	}
	
	public abstract LinkItem createLink(String caption, String url);
	public abstract TrayItem createTray(String caption);
	public abstract Page createPage(String caption, String author);
}

public abstract class Item {
	protected String caption;

	public Item(String caption) {
		super();
		this.caption = caption;
	}
	
	public abstract String makeHTML();
}

package factory;

import java.util.ArrayList;

public abstract class TrayItem extends Item {

	protected final ArrayList<Item> tray = new ArrayList<>();
	
	public TrayItem(String caption) {
		super(caption);
	}
	
	public void add(Item item) {
		tray.add(item);
	}
}

package factory;

public abstract class LinkItem extends Item {

	protected String url;
	
	public LinkItem(String caption, String url) {
		super(caption);
		this.url = url;
	}
}

package factory;

import java.io.BufferedWriter;
import java.io.FileOutputStream;
import java.io.OutputStreamWriter;
import java.nio.charset.StandardCharsets;
import java.util.ArrayList;

public abstract class Page {
	protected String title;
	protected String author;
	protected ArrayList<Item> content = new ArrayList<>();
	
	public Page(String title, String author) {
		this.title = title;
		this.author = author;
	}
	
	public void add(Item item) {
		content.add(item);
	}
	
	public void output() {
		System.out.println(this.makeHTML());
		
		try (BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(title + ".html"), StandardCharsets.UTF_8))) {
			bw.write(this.makeHTML());
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
	public abstract String makeHTML();
}