001/*
002 * (C) Copyright 2006-2007 Nuxeo SAS <http://nuxeo.com> and others
003 *
004 * All rights reserved. This program and the accompanying materials
005 * are made available under the terms of the Eclipse Public License v1.0
006 * which accompanies this distribution, and is available at
007 * http://www.eclipse.org/legal/epl-v10.html
008 *
009 * Contributors:
010 *     Jean-Marc Orliaguet, Chalmers
011 *
012 * $Id$
013 */
014
015package org.nuxeo.theme.protocol.nxtheme;
016
017import java.net.InetAddress;
018import java.net.URL;
019import java.net.URLConnection;
020import java.net.URLStreamHandler;
021
022public final class Handler extends URLStreamHandler {
023
024    @Override
025    protected URLConnection openConnection(URL url) {
026        return new Connection(url);
027    }
028
029    /**
030     * Theme URL do not reference any networked resource. This method is called by URL.equals and URL.hashCode so that
031     * we need override it to avoid DNS lookup for the theme host.
032     * 
033     * @param u a URL object
034     * @return null for url with nxtheme protocol, URLStreamHandler.getHostAddress(u) otherwise
035     */
036    @Override
037    protected synchronized InetAddress getHostAddress(URL u) {
038        if ("nxtheme".equals(u.getProtocol())) {
039            // do not do a DNS lookup for a theme resource
040            return null;
041        }
042        return super.getHostAddress(u);
043    }
044
045}