Copyright (c) 2004, 2013 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
/*******************************************************************************
 * Copyright (c) 2004, 2013 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 * 
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.osgi.storage.url;

import java.io.IOException;
import java.net.URL;
import java.net.URLConnection;
import org.eclipse.osgi.internal.messages.Msg;
import org.eclipse.osgi.service.urlconversion.URLConverter;
import org.eclipse.osgi.util.NLS;

The service implementation that allows bundleresource or bundleentry
URLs to be converted to native file URLs on the local file system.
Internal class.
/**
 * The service implementation that allows bundleresource or bundleentry
 * URLs to be converted to native file URLs on the local file system.
 * 
 * <p>Internal class.</p>
 */
public class BundleURLConverter implements URLConverter {

	/* (non-Javadoc)
	 * @see org.eclipse.osgi.service.urlconversion.URLConverter#toFileURL(java.net.URL)
	 */
	@Override
	public URL toFileURL(URL url) throws IOException {
		URLConnection connection = url.openConnection();
		if (connection instanceof BundleURLConnection) {
			URL result = ((BundleURLConnection) connection).getFileURL();
			/* If we got a connection then we know the resource exists in
			 * the bundle but if connection.getFileURL returned null then there
			 * was a problem extracting the file to disk. See bug 259241.
			 **/
			if (result == null)
				throw new IOException(NLS.bind(Msg.ECLIPSE_PLUGIN_EXTRACTION_PROBLEM, url));
			return result;
		}
		return url;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.osgi.service.urlconversion.URLConverter#resolve(java.net.URL)
	 */
	@Override
	public URL resolve(URL url) throws IOException {
		URLConnection connection = url.openConnection();
		if (connection instanceof BundleURLConnection)
			return ((BundleURLConnection) connection).getLocalURL();
		return url;
	}
}