Copyright (c) 2000, 2015 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) 2000, 2015 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.core.internal.boot;

import java.io.IOException;
import java.net.URL;
import org.eclipse.core.internal.runtime.CommonMessages;
import org.eclipse.osgi.util.NLS;

Platform URL support
platform:/base/	maps to platform installation location
/**
 * Platform URL support
 * platform:/base/	maps to platform installation location
 */
public class PlatformURLBaseConnection extends PlatformURLConnection {

	// platform/ protocol
	public static final String PLATFORM = "base"; //$NON-NLS-1$
	public static final String PLATFORM_URL_STRING = PlatformURLHandler.PROTOCOL + PlatformURLHandler.PROTOCOL_SEPARATOR + "/" + PLATFORM + "/"; //$NON-NLS-1$ //$NON-NLS-2$

	private static URL installURL;

	/*
	 * Constructor for the class.
	 */
	public PlatformURLBaseConnection(URL url) {
		super(url);
	}

	@Override
	protected boolean allowCaching() {
		return true;
	}

	@Override
	protected URL resolve() throws IOException {
		String spec = url.getFile().trim();
		if (spec.startsWith("/")) //$NON-NLS-1$
			spec = spec.substring(1);
		if (!spec.startsWith(PLATFORM + "/")) { //$NON-NLS-1$
			String message = NLS.bind(CommonMessages.url_badVariant, url);
			throw new IOException(message);
		}
		return spec.length() == PLATFORM.length() + 1 ? installURL : new URL(installURL, spec.substring(PLATFORM.length() + 1));
	}

	public static void startup(URL url) {
		// register connection type for platform:/base/ handling
		if (installURL != null)
			return;
		installURL = url;
		PlatformURLHandler.register(PLATFORM, PlatformURLBaseConnection.class);
	}
}