    001    /*
    002     * Licensed to the Apache Software Foundation (ASF) under one or more
    003     * contributor license agreements.  See the NOTICE file distributed with
    004     * this work for additional information regarding copyright ownership.
    005     * The ASF licenses this file to You under the Apache License, Version 2.0
    006     * (the "License"); you may not use this file except in compliance with
    007     * the License.  You may obtain a copy of the License at
    008     *
    009     *     http://www.apache.org/licenses/LICENSE-2.0
    010     *
    011     * Unless required by applicable law or agreed to in writing, software
    012     * distributed under the License is distributed on an "AS IS" BASIS,
    013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014     * See the License for the specific language governing permissions and
    015     * limitations under the License.
    016     */
    017    package org.apache.commons.scxml.env;
    018
    019    import java.io.Serializable;
    020    import java.net.MalformedURLException;
    021    import java.net.URL;
    022
    023    import org.apache.commons.logging.Log;
    024    import org.apache.commons.logging.LogFactory;
    025    import org.apache.commons.scxml.PathResolver;
    026
    027    /**
    028     * A PathResolver implementation that resolves against a base URL.
    029     *
    030     * @see org.apache.commons.scxml.PathResolver
    031     */
    032    public class URLResolver implements PathResolver, Serializable {
    033
    034        /** Serial version UID. */
    035        private static final long serialVersionUID = 1L;
    036
    037        /** Implementation independent log category. */
    038        private Log log = LogFactory.getLog(PathResolver.class);
    039
    040        /** The base URL to resolve against. */
    041        private URL baseURL = null;
    042
    043        /**
    044         * Constructor.
    045         *
    046         * @param baseURL The base URL to resolve against
    047         */
    048        public URLResolver(final URL baseURL) {
    049            this.baseURL = baseURL;
    050        }
    051
    052        /**
    053         * Uses URL(URL, String) constructor to combine URL's.
    054         * @see org.apache.commons.scxml.PathResolver#resolvePath(java.lang.String)
    055         */
    056        public String resolvePath(final String ctxPath) {
    057            URL combined;
    058            try {
    059                combined = new URL(baseURL, ctxPath);
    060                return combined.toString();
    061            } catch (MalformedURLException e) {
    062                log.error("Malformed URL", e);
    063            }
    064            return null;
    065        }
    066
    067        /**
    068         * @see org.apache.commons.scxml.PathResolver#getResolver(java.lang.String)
    069         */
    070        public PathResolver getResolver(final String ctxPath) {
    071            URL combined;
    072            try {
    073                combined = new URL(baseURL, ctxPath);
    074                return new URLResolver(combined);
    075            } catch (MalformedURLException e) {
    076                log.error("Malformed URL", e);
    077            }
    078            return null;
    079        }
    080
    081    }
    082