Copyright (c) 2004, 2009 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, 2009 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.service.urlconversion;

import java.io.IOException;
import java.net.URL;

The interface of the service that allows client-defined protocol
URLs to be converted to native file URLs on the local file system.

Clients may implement this interface.

Since:
3.1/**
 * The interface of the service that allows client-defined protocol
 * URLs to be converted to native file URLs on the local file system.
 * <p>
 * Clients may implement this interface.
 * </p>
 * 
 * @since 3.1
 */
public interface URLConverter {

	
Converts a URL that uses a user-defined protocol into a URL that uses the file
protocol. The contents of the URL may be extracted into a cache on the file-system
in order to get a file URL. 

If the protocol for the given URL is not recognized by this converter, the original
URL is returned as-is.

Params:
url – the original URL
Throws:
IOException – if an error occurs during the conversion
Returns:
the converted file URL or the original URL passed in if it is 
	not recognized by this converter
Since:
3.2/**
	 * Converts a URL that uses a user-defined protocol into a URL that uses the file
	 * protocol. The contents of the URL may be extracted into a cache on the file-system
	 * in order to get a file URL. 
	 * <p>
	 * If the protocol for the given URL is not recognized by this converter, the original
	 * URL is returned as-is.
	 * </p>
	 * @param url the original URL
	 * @return the converted file URL or the original URL passed in if it is 
	 * 	not recognized by this converter
	 * @throws IOException if an error occurs during the conversion
	 * @since 3.2
	 */
	public URL toFileURL(URL url) throws IOException;

	
Converts a URL that uses a client-defined protocol into a URL that uses a
protocol which is native to the Java class library (file, jar, http, etc).

Note however that users of this API should not assume too much about the
results of this method.  While it may consistently return a file: URL in certain
installation configurations, others may result in jar: or http: URLs.


If the protocol is not recognized by this converter, then the original URL is
returned as-is.

Params:
url – the original URL
Throws:
IOException – if unable to resolve URL
IOException – if an error occurs during the resolution
Returns:
the resolved URL or the original if the protocol is unknown to this converter
Since:
3.2/**
	 * Converts a URL that uses a client-defined protocol into a URL that uses a
	 * protocol which is native to the Java class library (file, jar, http, etc).
	 * <p>
	 * Note however that users of this API should not assume too much about the
	 * results of this method.  While it may consistently return a file: URL in certain
	 * installation configurations, others may result in jar: or http: URLs.
	 * </p>
	 * <p>
	 * If the protocol is not recognized by this converter, then the original URL is
	 * returned as-is.
	 * </p>
	 * @param url the original URL
	 * @return the resolved URL or the original if the protocol is unknown to this converter
	 * @exception IOException if unable to resolve URL
	 * @throws IOException if an error occurs during the resolution
	 * @since 3.2
	 */
	public URL resolve(URL url) throws IOException;
}