Copyright (c) 2004, 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
    Sergey Prigogin (Google) - use parameterized types (bug 442021)
/*******************************************************************************
 * Copyright (c) 2004, 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
 *     Sergey Prigogin (Google) - use parameterized types (bug 442021)
 *******************************************************************************/
package org.eclipse.core.internal.runtime;

import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.*;

public class DevClassPathHelper {

	// command line options
	public static final String PROP_DEV = "osgi.dev"; //$NON-NLS-1$

	static protected boolean inDevelopmentMode = false;
	static protected String[] devDefaultClasspath;
	static protected Properties devProperties = null;

	static {
		// Check the osgi.dev property to see if dev classpath entries have been defined.
		String osgiDev = Activator.getContext() == null ? System.getProperty(PROP_DEV) : Activator.getContext().getProperty(PROP_DEV);
		if (osgiDev != null) {
			try {
				inDevelopmentMode = true;
				URL location = new URL(osgiDev);
				devProperties = load(location);
				if (devProperties != null)
					devDefaultClasspath = getArrayFromList(devProperties.getProperty("*")); //$NON-NLS-1$
			} catch (MalformedURLException e) {
				devDefaultClasspath = getArrayFromList(osgiDev);
			}
		}
	}

	public static String[] getDevClassPath(String id) {
		String[] result = null;
		if (id != null && devProperties != null) {
			String entry = devProperties.getProperty(id);
			if (entry != null)
				result = getArrayFromList(entry);
		}
		if (result == null)
			result = devDefaultClasspath;
		return result;
	}

	
Returns the result of converting a list of comma-separated tokens into an array
Params:
prop – the initial comma-separated string
Returns:
the array of string tokens/**
	 * Returns the result of converting a list of comma-separated tokens into an array
	 * 
	 * @return the array of string tokens
	 * @param prop the initial comma-separated string
	 */
	public static String[] getArrayFromList(String prop) {
		if (prop == null || prop.trim().equals("")) //$NON-NLS-1$
			return new String[0];
		Vector<String> list = new Vector<>();
		StringTokenizer tokens = new StringTokenizer(prop, ","); //$NON-NLS-1$
		while (tokens.hasMoreTokens()) {
			String token = tokens.nextToken().trim();
			if (!token.equals("")) //$NON-NLS-1$
				list.addElement(token);
		}
		return list.isEmpty() ? new String[0] : (String[]) list.toArray(new String[list.size()]);
	}

	public static boolean inDevelopmentMode() {
		return inDevelopmentMode;
	}

	/*
	 * Load the given properties file
	 */
	private static Properties load(URL url) {
		Properties props = new Properties();
		try {
			InputStream is = null;
			try {
				is = url.openStream();
				props.load(is);
			} finally {
				if (is != null)
					is.close();
			}
		} catch (IOException e) {
			// TODO consider logging here
		}
		return props;
	}
}