001    // Copyright 2004, 2005 The Apache Software Foundation
002    //
003    // Licensed under the Apache License, Version 2.0 (the "License");
004    // you may not use this file except in compliance with the License.
005    // You may obtain a copy of the License at
006    //
007    //     http://www.apache.org/licenses/LICENSE-2.0
008    //
009    // Unless required by applicable law or agreed to in writing, software
010    // distributed under the License is distributed on an "AS IS" BASIS,
011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012    // See the License for the specific language governing permissions and
013    // limitations under the License.
014    
015    package org.apache.tapestry.asset;
016    
017    import java.io.InputStream;
018    import java.net.URL;
019    
020    import org.apache.hivemind.ApplicationRuntimeException;
021    import org.apache.hivemind.Location;
022    import org.apache.tapestry.Tapestry;
023    
024    /**
025     *  A reference to an external URL.  {@link ExternalAsset}s are not
026     *  localizable.
027     *
028     *  @author Howard Lewis Ship
029     * 
030     **/
031    
032    public class ExternalAsset extends AbstractAsset
033    {
034        private String _url;
035    
036        public ExternalAsset(String URL, Location location)
037        {
038            super(null, location);
039    
040            _url = URL;
041        }
042    
043        /**
044         *  Simply returns the URL of the external asset.
045         *
046         **/
047    
048        public String buildURL()
049        {
050            return _url;
051        }
052    
053        public InputStream getResourceAsStream()
054        {
055            URL url;
056    
057            try
058            {
059                url = new URL(_url);
060    
061                return url.openStream();
062            }
063            catch (Exception ex)
064            {
065                // MalrformedURLException or IOException
066    
067                throw new ApplicationRuntimeException(Tapestry.format("ExternalAsset.resource-missing", _url), ex);
068            }
069    
070        }
071    
072        public String toString()
073        {
074            return "ExternalAsset[" + _url + "]";
075        }
076    }