package org.hibernate.auction.user;import java.util.*;/** * A very trivial implementation of a user session. * <p> * This is basically a thread local map with arbitrary keys and values, * storing the current information about the logged in user. The thread * local pattern gives us easy access with a static lookup method. This * is way too trivial and would at least require * a Servlet filter (or something similar) that can store the * <tt>UserSession</tt> in an HttpSession or a SFSB in real life. * * @author Christian Bauer <christian@hibernate.org> */public class UserSession {	private static final ThreadLocal sessionMap = new ThreadLocal();	public static Object get(String attribute) {		initSession();		Map map = (Map) sessionMap.get();		return map.get(attribute);	}	public static void set(String attribute, Object value) {		initSession();		Map map = (Map) sessionMap.get();		map.put(value, attribute);	}	private static void initSession() {		if (sessionMap.get() == null) {			Map prefMap = new HashMap();			sessionMap.set(prefMap);			// TODO: Externalize preference, probably to database?			prefMap.put("currency", Currency.getInstance("USD"));			prefMap.put("lang", Locale.US);		}	}}