001/*
002 * (C) Copyright 2006-2007 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     Jean-Marc Orliaguet, Chalmers
018 *
019 * $Id$
020 */
021
022package org.nuxeo.theme.protocol.nxtheme;
023
024import java.net.InetAddress;
025import java.net.URL;
026import java.net.URLConnection;
027import java.net.URLStreamHandler;
028
029public final class Handler extends URLStreamHandler {
030
031    @Override
032    protected URLConnection openConnection(URL url) {
033        return new Connection(url);
034    }
035
036    /**
037     * Theme URL do not reference any networked resource. This method is called by URL.equals and URL.hashCode so that
038     * we need override it to avoid DNS lookup for the theme host.
039     * 
040     * @param u a URL object
041     * @return null for url with nxtheme protocol, URLStreamHandler.getHostAddress(u) otherwise
042     */
043    @Override
044    protected synchronized InetAddress getHostAddress(URL u) {
045        if ("nxtheme".equals(u.getProtocol())) {
046            // do not do a DNS lookup for a theme resource
047            return null;
048        }
049        return super.getHostAddress(u);
050    }
051
052}