001/*
002 * (C) Copyright 2011 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 *     Florent Guillaume
018 */
019package org.nuxeo.theme.html.servlets;
020
021import java.io.InputStream;
022import java.net.MalformedURLException;
023import java.net.URL;
024
025import javax.servlet.ServletContext;
026import javax.servlet.ServletContextEvent;
027import javax.servlet.ServletContextListener;
028
029import org.nuxeo.theme.ResourceResolver;
030
031/**
032 * Resolver for resources that checks the servlet context first.
033 *
034 * @since 5.5
035 */
036public class ServletResourceResolver extends ResourceResolver implements ServletContextListener {
037
038    protected ServletContext servletContext;
039
040    @Override
041    public URL getResource(String path) {
042        try {
043            URL url = servletContext.getResource("/" + path);
044            if (url != null) {
045                return url;
046            }
047        } catch (MalformedURLException e) {
048            // continue
049        }
050        return super.getResource(path);
051    }
052
053    @Override
054    public InputStream getResourceAsStream(String path) {
055        InputStream is = servletContext.getResourceAsStream("/" + path);
056        if (is != null) {
057            return is;
058        }
059        return super.getResourceAsStream(path);
060    }
061
062    @Override
063    public void contextInitialized(ServletContextEvent sce) {
064        servletContext = sce.getServletContext();
065        ResourceResolver.setInstance(this);
066    }
067
068    @Override
069    public void contextDestroyed(ServletContextEvent sce) {
070        servletContext = null;
071        ResourceResolver.setInstance(null);
072    }
073
074}