001    //$HeadURL: svn+ssh://jwilden@svn.wald.intevation.org/deegree/base/branches/2.5_testing/src/org/deegree/framework/util/WebappResourceResolver.java $
002    // $Id: WebappResourceResolver.java 18195 2009-06-18 15:55:39Z mschneider $
003    /*----------------------------------------------------------------------------
004     This file is part of deegree, http://deegree.org/
005     Copyright (C) 2001-2009 by:
006       Department of Geography, University of Bonn
007     and
008       lat/lon GmbH
009    
010     This library is free software; you can redistribute it and/or modify it under
011     the terms of the GNU Lesser General Public License as published by the Free
012     Software Foundation; either version 2.1 of the License, or (at your option)
013     any later version.
014     This library is distributed in the hope that it will be useful, but WITHOUT
015     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
016     FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
017     details.
018     You should have received a copy of the GNU Lesser General Public License
019     along with this library; if not, write to the Free Software Foundation, Inc.,
020     59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
021    
022     Contact information:
023    
024     lat/lon GmbH
025     Aennchenstr. 19, 53177 Bonn
026     Germany
027     http://lat-lon.de/
028    
029     Department of Geography, University of Bonn
030     Prof. Dr. Klaus Greve
031     Postfach 1147, 53001 Bonn
032     Germany
033     http://www.geographie.uni-bonn.de/deegree/
034    
035     e-mail: info@deegree.org
036    ----------------------------------------------------------------------------*/
037    
038    package org.deegree.framework.util;
039    
040    import java.io.File;
041    import java.net.MalformedURLException;
042    import java.net.URI;
043    import java.net.URL;
044    
045    import javax.servlet.ServletContext;
046    
047    import org.deegree.framework.log.ILogger;
048    
049    /**
050     * Utility class for resolving of references in webapp config files to {@link URL}s.
051     *
052     * @author <a href="mailto:schneider@lat-lon.de">Markus Schneider</a>
053     * @author last edited by: $Author: mschneider $
054     *
055     * @version $Revision: 18195 $, $Date: 2009-06-18 17:55:39 +0200 (Do, 18 Jun 2009) $
056     */
057    public class WebappResourceResolver {
058    
059        /**
060         * 'Heuristical' method to retrieve the {@link URL} for a file referenced from an init-param of
061         * a webapp config file which may be:
062         * <ul>
063         * <li>a (absolute) <code>URL</code></li>
064         * <li>a file location</li>
065         * <li>a (relative) URL which in turn is resolved using <code>ServletContext.getRealPath</code>
066         * </li>
067         * </ul>
068         *
069         * @param location
070         * @param context
071         * @param log
072         *            the log where errors are logged
073         * @return the full (and whitespace-escaped) URL
074         * @throws MalformedURLException
075         */
076        public static URL resolveFileLocation( String location, ServletContext context, ILogger log )
077                                throws MalformedURLException {
078            URL serviceConfigurationURL = null;
079    
080            log.logDebug( "Resolving configuration file location: '" + location + "'..." );
081            try {
082                // construction of URI performs whitespace escaping
083                serviceConfigurationURL = new URI( location ).toURL();
084            } catch ( Exception e ) {
085                log.logDebug( "No valid (absolute) URL. Trying context.getRealPath() now." );
086                String realPath = context.getRealPath( location );
087                if ( realPath == null ) {
088                    log.logDebug( "No 'real path' available. Trying to parse as a file location now." );
089                    serviceConfigurationURL = new File( location ).toURI().toURL();
090                } else {
091                    try {
092                        // realPath may either be a URL or a File
093                        serviceConfigurationURL = new URI( realPath ).toURL();
094                    } catch ( Exception e2 ) {
095                        log.logDebug( "'Real path' cannot be parsed as URL. " + "Trying to parse as a file location now." );
096                        // construction of URI performs whitespace escaping
097                        serviceConfigurationURL = new File( realPath ).toURI().toURL();
098                        log.logDebug( "serviceConfigurationURL: " + serviceConfigurationURL );
099                    }
100                }
101            }
102            return serviceConfigurationURL;
103        }
104    }