org.eclipse.stem.core/src/org/eclipse/stem/core/Utility.java

// Utility.java
package org.eclipse.stem.core;

/*******************************************************************************
 * Copyright (c) 2008 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.resource.ResourceSet;
import org.eclipse.emf.ecore.resource.impl.ResourceSetImpl;
import org.eclipse.emf.ecore.xmi.XMLResource;
import org.eclipse.emf.ecore.xmi.impl.XMIResourceFactoryImpl;
import org.eclipse.stem.core.common.Identifiable;

/**
 * This class contains common utility methods used in STEM.
 */
public class Utility {

	/**
	 * EMF Save Options, for properly serializing to UTF-8
	 */
	private static final Map<String,String> EMF_SAVE_OPTIONS 
		= new HashMap<String,String>();
	static {
		EMF_SAVE_OPTIONS.put(XMLResource.OPTION_ENCODING, "UTF-8");
	}
	
	/**
	 * @param identifableURI
	 *            the {@link URI} of file with a serialized {@link Identifiable}
	 * @return the {@link Identifiable} de-serialized from the file, or
	 *         <code>null</code> if an error occurred.
	 */
	public static Identifiable getIdentifiable(final URI identifableURI) {
		Identifiable retValue = null;

		try {
			final ResourceSet resourceSet = new ResourceSetImpl();

			resourceSet.getResourceFactoryRegistry().getExtensionToFactoryMap()
					.put("*", new XMIResourceFactoryImpl());
			resourceSet.getResourceFactoryRegistry().getProtocolToFactoryMap()
					.put("platform", new XMIResourceFactoryImpl());

			final Resource resource = resourceSet.getResource(identifableURI,
					true);
			retValue = (Identifiable) resource.getContents().get(0);
		} catch (final Exception e) {
			CorePlugin.logError(
					"The serialized instance of an Identifiable at \""
							+ identifableURI.toString()
							+ "\" was not found or was of the wrong format", e);
			retValue = null;
		}
		return retValue;
	} // getIdentifiable

	/**
	 * Serialize an {@link Identifiable}
	 * <p>
	 * Note this code is copied from
	 * org.eclipse.stem.internal.data.records.Record. That method should be
	 * removed and this one used instead.
	 * 
	 * @param identifiable
	 *            the {@link Identifiable} to be serialized.
	 * @param serializationURI
	 *            the {@link URI} that specifies where the {@link Identifiable}
	 *            is to be serialized.
	 * @throws IOException
	 *             if there is a problem serializing the {@link Identifiable}
	 */
	public static void serializeIdentifiable(final Identifiable identifiable,
			final URI serializationURI) throws IOException {
		final List<Identifiable> set = new ArrayList<Identifiable>();
		set.add(identifiable);
		serializeIdentifiables(set, serializationURI);
	} // serializeIdentifiable

	/**
	 * Serialize an {@link Identifiable}
	 * 
	 * @param identifiable
	 *            the {@link Identifiable} to be serialized.
	 * @param serializationURI
	 *            the {@link URI} that specifies where the {@link Identifiable}
	 *            is to be serialized.
	 * @throws IOException
	 *             if there is a problem serializing the {@link Identifiable}
	 */
	public static void serializeIdentifiables(final List<Identifiable> identifiables,
			final URI serializationURI) throws IOException {

		// This code could be running "stand alone" (i.e., not within eclipse),
		// thus the default factories for the extensions are not registered as
		// they would from their extension of
		// "org.eclipse.emf.ecore.extension_parser". So we need to register them
		// here.

		Resource.Factory.Registry.INSTANCE.getExtensionToFactoryMap().put("*",
				STEMXMIResourceFactoryImpl.INSTANCE);
		Resource.Factory.Registry.INSTANCE.getProtocolToFactoryMap().put(
				"platform", STEMXMIResourceFactoryImpl.INSTANCE);

		final ResourceSet resourceSet = new ResourceSetImpl();

		resourceSet.getResourceFactoryRegistry().getExtensionToFactoryMap()
				.put("*", STEMXMIResourceFactoryImpl.INSTANCE);

		resourceSet.getResourceFactoryRegistry().getProtocolToFactoryMap().put(
				"platform", STEMXMIResourceFactoryImpl.INSTANCE);

		final Resource resource = resourceSet.createResource(serializationURI);
		
		for (Identifiable id : identifiables) {
			resource.getContents().add(id);
		}

		resource.save(EMF_SAVE_OPTIONS);
	} // serializeIdentifiable
	
	/**
	 * Common method for determining the geographic level of a geographic key (last segment of a URI)
	 * @param key
	 * @return the level of the key
	 */
	public  static int keyLevel(final String key) {
		// ZZZ is special
		if(key.equalsIgnoreCase("ZZZ")) return -1;
		int level = 0;
		int start = 0;
		for (int temp = key.indexOf("-"); temp > 0;) { //$NON-NLS-1$
			level++;
			start += temp + 1;
			temp = key.substring(start).indexOf("-"); //$NON-NLS-1$
		} // for
		return level;
	} // keyLevel
} // Utility