AbstractInputData.java

/**
 * Copyright (c) 2012, 2014 Obeo.
 * 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:
 *     Obeo - initial API and implementation
 */
package org.eclipse.emf.compare.tests.framework;

import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Collections;
import java.util.List;

import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.common.util.WrappedException;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.resource.ResourceSet;
import org.eclipse.emf.ecore.util.EcoreUtil;
import org.eclipse.emf.ecore.xmi.impl.XMIResourceFactoryImpl;

/**
 * Implementations of this class can be used to load models from the class' class loader.
 * 
 * @author <a href="mailto:laurent.goubet@obeo.fr">Laurent Goubet</a>
 */
public abstract class AbstractInputData {
	/**
	 * Tries and locate a model in the current class' classpath.
	 * 
	 * @param string
	 *            Relative path to the model we seek (relative to this class).
	 * @return The loaded resource.
	 * @throws IOException
	 *             Thrown if we could not access either this class' resource, or the file towards which
	 *             <code>string</code> points.
	 */
	protected Resource loadFromClassLoader(String string) throws IOException {
		final URL fileURL = getClass().getResource(string);
		final InputStream str = fileURL.openStream();
		final URI uri = URI.createURI(fileURL.toString());

		Resource.Factory resourceFactory = Resource.Factory.Registry.INSTANCE.getFactory(uri);
		if (resourceFactory == null) {
			// Most likely a standalone run. Try with a plain XMI resource
			resourceFactory = new XMIResourceFactoryImpl();
		}

		// resourceFactory cannot be null
		Resource res = resourceFactory.createResource(uri);
		res.load(str, Collections.emptyMap());
		str.close();
		return res;
	}

	/**
	 * Tries and locate a model in the current class' classpath.
	 * 
	 * @param string
	 *            Relative path to the model we seek (relative to this class).
	 * @param resourceSet
	 *            the resource set in which to load the resource.
	 * @return The loaded resource.
	 * @throws IOException
	 *             Thrown if we could not access either this class' resource, or the file towards which
	 *             <code>path</code> points.
	 */
	protected Resource loadFromClassLoader(String path, ResourceSet resourceSet) throws IOException {
		final URL fileURL = getClass().getResource(path);
		final URI uri = URI.createURI(fileURL.toString());

		final Resource existing = resourceSet.getResource(uri, false);
		if (existing != null) {
			return existing;
		}

		InputStream stream = null;
		Resource resource = null;
		try {
			resource = resourceSet.createResource(uri);
			stream = fileURL.openStream();
			resource.load(stream, Collections.emptyMap());
		} catch (IOException | WrappedException e) {
			// return null
		} finally {
			if (stream != null) {
				try {
					stream.close();
				} catch (IOException e) {
					// Should have been caught by the outer try
				}
			}
		}

		return resource;
	}

	public ResourceSet loadFromClassLoader(List<String> paths, ResourceSet resourceSet) throws IOException {
		for (String path : paths) {
			loadFromClassLoader(path, resourceSet);
			EcoreUtil.resolveAll(resourceSet);
		}
		return resourceSet;
	}
}