package databases;

import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

/**
 * @author   Giorgio Ravera
 */
public class DatabaseRicerche
{
	protected static DatabaseRicerche theInstance;
	
	protected List<String> keywords = new LinkedList<String>();
	private boolean signaled=false;

	private DatabaseRicerche() { super(); }
	
	public static DatabaseRicerche getInstance()
	{
		if (theInstance == null)
		{	
			theInstance = new DatabaseRicerche();
		}
		return (DatabaseRicerche) theInstance;
	}
	
	public void add(String s)
	{
		if(!keywords.contains(s))
		{
			keywords.add(s);
			signaled = true;
		}
		else
			System.out.println("Gia presente");
	}
	
	public Iterator<String> iterator()
	{
		return keywords.iterator();
	}

	public void remove(String s)
	{
		if(keywords.contains(s))
			keywords.remove(s);
	}
		
	public void clear()
	{
		keywords.clear();
	}
}
