plugins/org.eclipse.m2m.qvt.oml/src/org/eclipse/m2m/internal/qvt/oml/compiler/PlatformNamespaceUriResourceMap.java

package org.eclipse.m2m.internal.qvt.oml.compiler;

import java.util.HashMap;

import org.eclipse.emf.common.util.URI;
import org.eclipse.emf.ecore.EPackage;
import org.eclipse.emf.ecore.plugin.EcorePlugin;
import org.eclipse.emf.ecore.resource.Resource;
import org.eclipse.emf.ecore.resource.ResourceSet;
import org.eclipse.emf.ecore.resource.URIConverter;
import org.eclipse.m2m.internal.qvt.oml.emf.util.EmfUtil;

@SuppressWarnings("serial")
public class PlatformNamespaceUriResourceMap extends HashMap<URI, Resource> {

	private EPackage.Registry registry;
	private URIConverter uriConverter;
	private boolean isInitialized= false;

	public PlatformNamespaceUriResourceMap(ResourceSet resourceSet) {
		this(resourceSet.getPackageRegistry(), resourceSet.getURIConverter());
	}

	public PlatformNamespaceUriResourceMap(EPackage.Registry registry, URIConverter uriConverter) {
		this.registry = registry;
		this.uriConverter = uriConverter;
	}

	private void initialize() {
		uriConverter.getURIMap().putAll(EcorePlugin.computePlatformURIMap(true));
		isInitialized = true;
	}

	@Override
	public Resource get(Object key) {
		Resource resource = super.get(key);

		if (resource == null && key instanceof URI) {
			URI uri = (URI) key;

			if (uri.isPlatform() && !URIConverter.INSTANCE.exists(uri, null)) {

				if (!isInitialized) {
					initialize();
				}

				URI normalizedUri = uriConverter.normalize(uri);

				if (uriConverter.exists(normalizedUri, null)) {
					Resource packageResource = null;
					try {
						packageResource = EmfUtil.loadResource(normalizedUri);
						EPackage rootPackage = EmfUtil.getFirstEPackageContent(packageResource);

						if (rootPackage != null) {
							EPackage ePackage = registry.getEPackage(rootPackage.getNsURI());

							if (ePackage != null) {
								resource = ePackage.eResource();

								if (resource != null) {
									put(uri, resource);
								}
							}
						}
					}
					catch (Throwable t) {}
					finally {
						if (packageResource != null) {
							packageResource.unload();
						}
					}
				}
			}
		}

		return resource;
	}

}