org.deegree.commons.utils.net.DURL.java Source code

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Here is the source code for org.deegree.commons.utils.net.DURL.java

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//$HeadURL: http://svn.wald.intevation.org/svn/deegree/deegree3/branches/3.0/deegree-core/src/main/java/org/deegree/commons/utils/net/DURL.java $
/*----------------------------------------------------------------------------
 This file is part of deegree, http://deegree.org/
 Copyright (C) 2001-2010 by:
 - Department of Geography, University of Bonn -
 and
 - lat/lon GmbH -
    
 This library is free software; you can redistribute it and/or modify it under
 the terms of the GNU Lesser General Public License as published by the Free
 Software Foundation; either version 2.1 of the License, or (at your option)
 any later version.
 This library is distributed in the hope that it will be useful, but WITHOUT
 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 details.
 You should have received a copy of the GNU Lesser General Public License
 along with this library; if not, write to the Free Software Foundation, Inc.,
 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
    
 Contact information:
    
 lat/lon GmbH
 Aennchenstr. 19, 53177 Bonn
 Germany
 http://lat-lon.de/
    
 Department of Geography, University of Bonn
 Prof. Dr. Klaus Greve
 Postfach 1147, 53001 Bonn
 Germany
 http://www.geographie.uni-bonn.de/deegree/
    
 e-mail: info@deegree.org
 ----------------------------------------------------------------------------*/
package org.deegree.commons.utils.net;

import static java.util.Collections.synchronizedMap;
import static org.deegree.commons.utils.net.HttpUtils.enableProxyUsage;
import static org.slf4j.LoggerFactory.getLogger;

import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLStreamHandler;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.httpclient.HttpClient;
import org.apache.commons.httpclient.methods.GetMethod;
import org.slf4j.Logger;

/**
 * 
 * [D]eegree[URL]
 * 
 * @author <a href="mailto:schmitz@lat-lon.de">Andreas Schmitz</a>
 * @author last edited by: $Author: aschmitz $
 * 
 * @version $Revision: 25448 $, $Date: 2010-07-20 03:24:59 -0700 (Tue, 20 Jul 2010) $
 */
public class DURL {

    private static final Logger LOG = getLogger(DURL.class);

    private static final Map<String, Class<? extends URLStreamHandler>> handlers = synchronizedMap(
            new HashMap<String, Class<? extends URLStreamHandler>>());

    private URLStreamHandler handler;

    private URL url;

    static {
        handlers.put("data", DataHandler.class);
    }

    /**
     * @param url
     */
    public DURL(String url) {
        String protocol = url.split(":")[0];
        Class<? extends URLStreamHandler> handler = handlers.get(protocol);
        if (handler != null) {
            try {
                this.handler = handler.newInstance();
                this.url = new URL(null, url, this.handler);
            } catch (InstantiationException e) {
                LOG.debug("URL handler '{}' could not be instantiated: '{}'", handler.getSimpleName(),
                        e.getLocalizedMessage());
                LOG.trace("Stack trace:", e);
            } catch (IllegalAccessException e) {
                LOG.debug("URL handler constructor of '{}' could not be used: '{}'", handler.getSimpleName(),
                        e.getLocalizedMessage());
                LOG.trace("Stack trace:", e);
            } catch (MalformedURLException e) {
                LOG.debug("URL '{}' could not be instantiated: '{}'", url, e.getLocalizedMessage());
                LOG.trace("Stack trace:", e);
            }
        } else {
            try {
                this.url = new URL(url);
            } catch (MalformedURLException e) {
                LOG.debug("URL '{}' could not be instantiated: '{}'", url, e.getLocalizedMessage());
                LOG.trace("Stack trace:", e);
            }
        }
    }

    /**
     * @param protocol
     * @param handler
     */
    public static void registerHandler(String protocol, Class<? extends URLStreamHandler> handler) {
        handlers.put(protocol, handler);
    }

    /**
     * @return true, if the underlying URL object could be instantiated
     */
    public boolean valid() {
        return url != null;
    }

    /**
     * @return the underlying URL
     */
    public URL getURL() {
        return url;
    }

    /**
     * @return an input stream from the URL
     * @throws IOException
     */
    public InputStream openStream() throws IOException {
        // custom handlers should handle proxies themselves
        if (handler != null) {
            return url.openStream();
        }

        HttpClient client = enableProxyUsage(new HttpClient(), this);
        GetMethod get = new GetMethod(url.toExternalForm());
        client.executeMethod(get);
        return get.getResponseBodyAsStream();
    }

}