plugins/org.eclipse.sphinx.emf.check/src/org/eclipse/sphinx/emf/check/CheckValidatorRegistry.java - sphinx/org.eclipse.sphinx - Git at Google

 /**
  * <copyright>
  *
  * Copyright (c) 2014-2015 itemis and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v2.0
  * which accompanies this distribution, and is available at
  * https://www.eclipse.org/org/documents/epl-2.0/EPL-2.0.html
  *
  * Contributors:
  *     itemis - Initial API and implementation
  *     itemis - [455185] Check Framework incompatible with QVTO metamodel
  *     itemis - [458403] CheckValidatorRegistry.getCheckModelURI(String) should be null-safe
  *     itemis - [458405] CheckValidatorRegistry.register(*) should be public
  *     itemis - [458921] Newly introduced registries for metamodel serives, check validators and workflow contributors are not standalone-safe
  *     itemis - [458976] Validators are not singleton when they implement checks for different EPackages
  *     itemis - [461051] API to get all registered check validators
  *     itemis - [478811] Check validation may compromise EMF Validation-based validation
  *
  * </copyright>
  */
 package org.eclipse.sphinx.emf.check;

 import java.lang.annotation.Annotation;
 import java.lang.reflect.Method;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Map;
 import java.util.Set;

 import org.eclipse.core.runtime.Assert;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IExtensionRegistry;
 import org.eclipse.core.runtime.ILog;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.emf.common.util.URI;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.EPackage;
 import org.eclipse.emf.ecore.EValidator;
 import org.eclipse.osgi.util.NLS;
 import org.eclipse.sphinx.emf.check.catalog.Catalog;
 import org.eclipse.sphinx.emf.check.internal.Activator;
 import org.eclipse.sphinx.emf.check.internal.CheckValidatorDescriptor;
 import org.eclipse.sphinx.emf.check.internal.EPackageMappings;
 import org.eclipse.sphinx.emf.check.util.CheckValidationUtil;
 import org.eclipse.sphinx.emf.util.EObjectUtil;
 import org.eclipse.sphinx.emf.util.EcoreResourceUtil;
 import org.eclipse.sphinx.emf.validation.ICompositeValidator;
 import org.eclipse.sphinx.platform.util.PlatformLogUtil;
 import org.eclipse.sphinx.platform.util.StatusUtil;

 /**
  * A validation registry singleton which backs a standard EMF validation
  * {@link org.eclipse.emf.ecore.EValidator.Registry registry}. When a check validator is called for the first time, the
  * registry reads all the contributed check validators and initializes its internal map, which is then used to retrieve
  * check catalogs from validator class names. Check validators are contributed through the
  * <code>org.eclipse.sphinx.emf.check.chekvalidators</code> extension point. A check validator contribution is a couple
  * of a validator class and optionally a check catalog. By default, the {@link org.eclipse.emf.ecore.EPackage ePackage}
  * affected by the validator is inferred from the set of the annotated method parameters provided by the validator.
  */
 public class CheckValidatorRegistry {

 	private static final String EXTP_CHECK_VALIDATORS = "org.eclipse.sphinx.emf.check.checkvalidators"; //$NON-NLS-1$
 	private static final String NODE_VALIDATOR = "validator"; //$NON-NLS-1$
 	private static final String NODE_EPACKAGE_MAPPING = "ePackageMapping"; //$NON-NLS-1$
 	private static final String ATTR_EOBJECT_WRAPPER_PACKAGE_NAME = "eObjectWrapperPackageName"; //$NON-NLS-1$
 	private static final String ATTR_EPACKAGE_NS_URI = "ePackageNsURI"; //$NON-NLS-1$

 	/**
 	 * The singleton instance of this registry.
 	 */
 	public static final CheckValidatorRegistry INSTANCE = new CheckValidatorRegistry(Platform.getExtensionRegistry(), EValidator.Registry.INSTANCE,
 			PlatformLogUtil.getLog(Activator.getPlugin()));

 	protected Map<ICheckValidator, URI> checkValidatorToCheckCatalogURIMap = null;
 	protected Map<URI, Set<ICheckValidator>> checkCatalogURIToCheckValidatorsMap = null;

 	protected Map<URI, Catalog> uriToCheckCatalogMap = new HashMap<URI, Catalog>();

 	protected IExtensionRegistry extensionRegistry;

 	protected EValidator.Registry eValidatorRegistry;

 	private ILog logger;

 	protected CheckValidatorRegistry(IExtensionRegistry extensionRegistry, EValidator.Registry eValidatorRegistry, ILog logger) {
 		Assert.isNotNull(extensionRegistry);
 		Assert.isNotNull(eValidatorRegistry);
 		Assert.isNotNull(logger);

 		this.extensionRegistry = extensionRegistry;
 		this.eValidatorRegistry = eValidatorRegistry;
 		this.logger = logger;
 	}

 	private EValidator.Registry getEValidatorRegistry() {
 		initialize();
 		return eValidatorRegistry;
 	}

 	private Map<ICheckValidator, URI> getCheckValidatorToCheckCatalogURIMap() {
 		initialize();
 		return checkValidatorToCheckCatalogURIMap != null ? checkValidatorToCheckCatalogURIMap : Collections.<ICheckValidator, URI> emptyMap();
 	}

 	private Map<URI, Set<ICheckValidator>> getCheckCatalogURIToCheckValidatorsMap() {
 		initialize();
 		return checkCatalogURIToCheckValidatorsMap != null ? checkCatalogURIToCheckValidatorsMap : Collections.<URI, Set<ICheckValidator>> emptyMap();
 	}

 	private void initialize() {
 		if (extensionRegistry == null) {
 			return;
 		}

 		if (checkValidatorToCheckCatalogURIMap == null || checkCatalogURIToCheckValidatorsMap == null) {
 			checkValidatorToCheckCatalogURIMap = new HashMap<ICheckValidator, URI>();
 			checkCatalogURIToCheckValidatorsMap = new HashMap<URI, Set<ICheckValidator>>();

 			// Create a temporary objects
 			Map<String, CheckValidatorDescriptor> checkValidatorClassNameToCheckValidatorDescriptorMap = new HashMap<String, CheckValidatorDescriptor>();
 			EPackageMappings ePackageMappings = new EPackageMappings();

 			// First iteration to detect duplicate check validator contributions and initialize check validator
 			// descriptor map
 			for (IConfigurationElement checkValidatorConfigurationElement : extensionRegistry.getConfigurationElementsFor(EXTP_CHECK_VALIDATORS)) {
 				try {
 					if (NODE_VALIDATOR.equals(checkValidatorConfigurationElement.getName())) {
 						CheckValidatorDescriptor checkValidatorDescriptor = new CheckValidatorDescriptor(checkValidatorConfigurationElement);
 						String checkValidatorClassName = checkValidatorDescriptor.getClassName();
 						if (checkValidatorClassNameToCheckValidatorDescriptorMap.containsKey(checkValidatorClassName)) {
 							logWarning("Duplicate validator contribution found for: " + checkValidatorClassName); //$NON-NLS-1$
 							continue;
 						}
 						checkValidatorClassNameToCheckValidatorDescriptorMap.put(checkValidatorClassName, checkValidatorDescriptor);
 					} else if (NODE_EPACKAGE_MAPPING.equals(checkValidatorConfigurationElement.getName())) {
 						String javaPackageName = checkValidatorConfigurationElement.getAttribute(ATTR_EOBJECT_WRAPPER_PACKAGE_NAME);
 						String ePackageNsURI = checkValidatorConfigurationElement.getAttribute(ATTR_EPACKAGE_NS_URI);
 						Object ePackageObject = EPackage.Registry.INSTANCE.get(ePackageNsURI);
 						if (ePackageObject == null) {
 							logError("Unable to find EPackage for ", ePackageNsURI); //$NON-NLS-1$
 						}
 						ePackageMappings.put(javaPackageName, ePackageObject);
 					}
 				} catch (Exception ex) {
 					logError(ex);
 				}
 			}

 			// Second iteration to register the contributed check validators with EMF's EValidator registry and check
 			// catalog URI map
 			for (CheckValidatorDescriptor checkValidatorDescriptor : checkValidatorClassNameToCheckValidatorDescriptorMap.values()) {
 				try {
 					// Create instance of contributed check validator
 					ICheckValidator validator = checkValidatorDescriptor.newInstance();

 					// Register check validator upon all EPackages that are affected by the former
 					Set<Class<?>> classesUnderCheck = findClassesUnderCheck(validator.getClass());
 					Set<EPackage> affectedEPackages = findAffectedEPackages(classesUnderCheck, ePackageMappings);
 					for (EPackage affectedEPackage : affectedEPackages) {
 						addValidator(affectedEPackage, validator);
 					}

 					URI catalogURI = checkValidatorDescriptor.getCatalogURI();
 					checkValidatorToCheckCatalogURIMap.put(validator, catalogURI);
 					if (catalogURI != null) {
 						Set<ICheckValidator> checkValidators = checkCatalogURIToCheckValidatorsMap.get(catalogURI);
 						if (checkValidators == null) {
 							checkValidators = new HashSet<ICheckValidator>();
 							checkCatalogURIToCheckValidatorsMap.put(catalogURI, checkValidators);
 						}
 						checkValidators.add(validator);
 					}
 				} catch (Exception ex) {
 					logError(ex);
 				}
 			}

 			// Clear temporary objects
 			checkValidatorClassNameToCheckValidatorDescriptorMap.clear();
 			ePackageMappings.clear();
 		}
 	}

 	/**
 	 * Retrieves the classes (typically metamodel element types) from the arguments of the check validator methods that
 	 * are annotated with @Check.
 	 *
 	 * @param validatorClass
 	 * @return
 	 */
 	private Set<Class<?>> findClassesUnderCheck(Class<? extends ICheckValidator> validatorClass) {
 		Assert.isNotNull(validatorClass);

 		Set<Class<?>> classesUnderCheck = new HashSet<Class<?>>();
 		Collection<Method> methods = CheckValidationUtil.getDeclaredCheckMethods(validatorClass);
 		for (Method method : methods) {
 			Annotation[] annotations = method.getAnnotations();
 			for (Annotation annotation : annotations) {
 				Class<? extends Annotation> annotationType = annotation.annotationType();
 				if (annotationType.equals(Check.class)) {
 					Class<?>[] parameterTypes = method.getParameterTypes();
 					if (parameterTypes.length > 0) {
 						classesUnderCheck.add(parameterTypes[0]);
 					}
 				}
 			}
 		}
 		return classesUnderCheck;
 	}

 	/**
 	 * Retrieves the set {@link EPackage}s behind the given set of classes to be checked.
 	 *
 	 * @param classesUnderCheck
 	 * @return
 	 */
 	private Set<EPackage> findAffectedEPackages(Set<Class<?>> classesUnderCheck, EPackageMappings ePackageMappings) {
 		Assert.isNotNull(classesUnderCheck);

 		Set<EPackage> affectedEPackages = new HashSet<EPackage>();
 		for (Class<?> classUnderCheck : classesUnderCheck) {
 			EPackage ePackage = findAffectedEPackage(classUnderCheck, ePackageMappings);
 			if (ePackage == null) {
 				logError("Unable to find EPackage for ", classUnderCheck.getName()); //$NON-NLS-1$
 				continue;
 			}
 			affectedEPackages.add(ePackage);
 		}
 		return affectedEPackages;
 	}

 	private EPackage findAffectedEPackage(Class<?> classUnderCheck, EPackageMappings ePackageMappings) {
 		Assert.isNotNull(ePackageMappings);

 		EPackage ePackage = ePackageMappings.getEPackageFor(classUnderCheck);
 		if (ePackage != null) {
 			return ePackage;
 		}

 		ePackage = EObjectUtil.findEPackage(classUnderCheck);
 		if (ePackage != null) {
 			ePackageMappings.put(classUnderCheck.getName(), ePackage);
 		}
 		return ePackage;
 	}

 	public void addValidator(EPackage ePackage, EValidator validator) {
 		// Retrieve existing validator for given EPackage if any
 		EValidator existingValidator = eValidatorRegistry.getEValidator(ePackage);

 		// No validator for given EPackage so far?
 		if (existingValidator == null) {
 			// Register given check validator as is
 			eValidatorRegistry.put(ePackage, validator);
 		}
 		// Existing validator being a composite validator?
 		else if (existingValidator instanceof ICompositeValidator) {
 			// Add given check validator as additional child validator
 			((ICompositeValidator) existingValidator).addValidator(validator);
 		}
 		// Existing validator is an EValidator or another check validator
 		else {
 			// Replace existing validator by a composite validator containing existing validator and given check
 			// validator as child validators
 			ICompositeValidator compositeValidator = new CompositeValidator();
 			compositeValidator.addValidator(existingValidator);
 			compositeValidator.addValidator(validator);
 			eValidatorRegistry.put(ePackage, compositeValidator);
 		}
 	}

 	/**
 	 * Retrieve a check-based validator contributed through the <code>org.eclipse.sphinx.emf.check.chekvalidators</code>
 	 * extension point for the given package.
 	 *
 	 * @param ePackage
 	 * @return
 	 * @throws CoreException
 	 */
 	public EValidator getValidator(EPackage ePackage) {
 		EValidator eValidator = getEValidatorRegistry().getEValidator(ePackage);
 		if (eValidator instanceof ICheckValidator || eValidator instanceof ICompositeValidator) {
 			return eValidator;
 		}
 		return null;
 	}

 	/**
 	 * Returns the URI of a check catalog associated with given check validator.
 	 *
 	 * @param checkValidator
 	 * @return
 	 */
 	public URI getCheckCatalogURI(ICheckValidator checkValidator) {
 		return getCheckValidatorToCheckCatalogURIMap().get(checkValidator);
 	}

 	public Catalog getCheckCatalog(ICheckValidator checkValidator) {
 		URI checkCatalogURI = getCheckCatalogURI(checkValidator);
 		if (checkCatalogURI != null) {
 			return loadCheckCatalog(checkCatalogURI);
 		}
 		return null;
 	}

 	private Catalog loadCheckCatalog(URI checkCatalogURI) {
 		Catalog catalog = uriToCheckCatalogMap.get(checkCatalogURI);
 		if (catalog == null) {
 			EObject eObject = EcoreResourceUtil.loadEObject(null, checkCatalogURI.appendFragment("/")); //$NON-NLS-1$
 			if (!(eObject instanceof Catalog)) {
 				throw new IllegalStateException("Unable to find the check catalog for URI '" + checkCatalogURI + "'"); //$NON-NLS-1$ //$NON-NLS-2$
 			}
 			catalog = (Catalog) eObject;
 			uriToCheckCatalogMap.put(checkCatalogURI, catalog);
 		}
 		return catalog;
 	}

 	public Collection<Catalog> getCheckCatalogs() {
 		Set<URI> allCalalogURIs = getCheckCatalogURIToCheckValidatorsMap().keySet();
 		for (URI uri : allCalalogURIs) {
 			if (uriToCheckCatalogMap.get(uri) == null) {
 				loadCheckCatalog(uri);
 			}
 		}
 		return uriToCheckCatalogMap.values();
 	}

 	public Collection<ICheckValidator> getCheckValidators() {
 		return getCheckValidatorToCheckCatalogURIMap().keySet();
 	}

 	private void logWarning(String msgId, Object... objects) {
 		logWarning(new RuntimeException(NLS.bind(msgId, objects)));
 	}

 	private void logWarning(Throwable throwable) {
 		logger.log(StatusUtil.createWarningStatus(Activator.getDefault(), throwable));
 	}

 	private void logError(String msgId, Object... objects) {
 		logError(new RuntimeException(NLS.bind(msgId, objects)));
 	}

 	private void logError(Throwable throwable) {
 		logger.log(StatusUtil.createErrorStatus(Activator.getDefault(), throwable));
 	}
 }
	/**
	* <copyright>
	*
	* Copyright (c) 2014-2015 itemis and others.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v2.0
	* which accompanies this distribution, and is available at
	* https://www.eclipse.org/org/documents/epl-2.0/EPL-2.0.html
	*
	* Contributors:
	* itemis - Initial API and implementation
	* itemis - [455185] Check Framework incompatible with QVTO metamodel
	* itemis - [458403] CheckValidatorRegistry.getCheckModelURI(String) should be null-safe
	* itemis - [458405] CheckValidatorRegistry.register(*) should be public
	* itemis - [458921] Newly introduced registries for metamodel serives, check validators and workflow contributors are not standalone-safe
	* itemis - [458976] Validators are not singleton when they implement checks for different EPackages
	* itemis - [461051] API to get all registered check validators
	* itemis - [478811] Check validation may compromise EMF Validation-based validation
	*
	* </copyright>
	*/
	package org.eclipse.sphinx.emf.check;

	import java.lang.annotation.Annotation;
	import java.lang.reflect.Method;
	import java.util.Collection;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.Map;
	import java.util.Set;

	import org.eclipse.core.runtime.Assert;
	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.IConfigurationElement;
	import org.eclipse.core.runtime.IExtensionRegistry;
	import org.eclipse.core.runtime.ILog;
	import org.eclipse.core.runtime.Platform;
	import org.eclipse.emf.common.util.URI;
	import org.eclipse.emf.ecore.EObject;
	import org.eclipse.emf.ecore.EPackage;
	import org.eclipse.emf.ecore.EValidator;
	import org.eclipse.osgi.util.NLS;
	import org.eclipse.sphinx.emf.check.catalog.Catalog;
	import org.eclipse.sphinx.emf.check.internal.Activator;
	import org.eclipse.sphinx.emf.check.internal.CheckValidatorDescriptor;
	import org.eclipse.sphinx.emf.check.internal.EPackageMappings;
	import org.eclipse.sphinx.emf.check.util.CheckValidationUtil;
	import org.eclipse.sphinx.emf.util.EObjectUtil;
	import org.eclipse.sphinx.emf.util.EcoreResourceUtil;
	import org.eclipse.sphinx.emf.validation.ICompositeValidator;
	import org.eclipse.sphinx.platform.util.PlatformLogUtil;
	import org.eclipse.sphinx.platform.util.StatusUtil;

	/**
	* A validation registry singleton which backs a standard EMF validation
	* {@link org.eclipse.emf.ecore.EValidator.Registry registry}. When a check validator is called for the first time, the
	* registry reads all the contributed check validators and initializes its internal map, which is then used to retrieve
	* check catalogs from validator class names. Check validators are contributed through the
	* <code>org.eclipse.sphinx.emf.check.chekvalidators</code> extension point. A check validator contribution is a couple
	* of a validator class and optionally a check catalog. By default, the {@link org.eclipse.emf.ecore.EPackage ePackage}
	* affected by the validator is inferred from the set of the annotated method parameters provided by the validator.
	*/
	public class CheckValidatorRegistry {

	private static final String EXTP_CHECK_VALIDATORS = "org.eclipse.sphinx.emf.check.checkvalidators"; //$NON-NLS-1$
	private static final String NODE_VALIDATOR = "validator"; //$NON-NLS-1$
	private static final String NODE_EPACKAGE_MAPPING = "ePackageMapping"; //$NON-NLS-1$
	private static final String ATTR_EOBJECT_WRAPPER_PACKAGE_NAME = "eObjectWrapperPackageName"; //$NON-NLS-1$
	private static final String ATTR_EPACKAGE_NS_URI = "ePackageNsURI"; //$NON-NLS-1$

	/**
	* The singleton instance of this registry.
	*/
	public static final CheckValidatorRegistry INSTANCE = new CheckValidatorRegistry(Platform.getExtensionRegistry(), EValidator.Registry.INSTANCE,
	PlatformLogUtil.getLog(Activator.getPlugin()));

	protected Map<ICheckValidator, URI> checkValidatorToCheckCatalogURIMap = null;
	protected Map<URI, Set<ICheckValidator>> checkCatalogURIToCheckValidatorsMap = null;

	protected Map<URI, Catalog> uriToCheckCatalogMap = new HashMap<URI, Catalog>();

	protected IExtensionRegistry extensionRegistry;

	protected EValidator.Registry eValidatorRegistry;

	private ILog logger;

	protected CheckValidatorRegistry(IExtensionRegistry extensionRegistry, EValidator.Registry eValidatorRegistry, ILog logger) {
	Assert.isNotNull(extensionRegistry);
	Assert.isNotNull(eValidatorRegistry);
	Assert.isNotNull(logger);

	this.extensionRegistry = extensionRegistry;
	this.eValidatorRegistry = eValidatorRegistry;
	this.logger = logger;
	}

	private EValidator.Registry getEValidatorRegistry() {
	initialize();
	return eValidatorRegistry;
	}

	private Map<ICheckValidator, URI> getCheckValidatorToCheckCatalogURIMap() {
	initialize();
	return checkValidatorToCheckCatalogURIMap != null ? checkValidatorToCheckCatalogURIMap : Collections.<ICheckValidator, URI> emptyMap();
	}

	private Map<URI, Set<ICheckValidator>> getCheckCatalogURIToCheckValidatorsMap() {
	initialize();
	return checkCatalogURIToCheckValidatorsMap != null ? checkCatalogURIToCheckValidatorsMap : Collections.<URI, Set<ICheckValidator>> emptyMap();
	}

	private void initialize() {
	if (extensionRegistry == null) {
	return;
	}

	if (checkValidatorToCheckCatalogURIMap == null \|\| checkCatalogURIToCheckValidatorsMap == null) {
	checkValidatorToCheckCatalogURIMap = new HashMap<ICheckValidator, URI>();
	checkCatalogURIToCheckValidatorsMap = new HashMap<URI, Set<ICheckValidator>>();

	// Create a temporary objects
	Map<String, CheckValidatorDescriptor> checkValidatorClassNameToCheckValidatorDescriptorMap = new HashMap<String, CheckValidatorDescriptor>();
	EPackageMappings ePackageMappings = new EPackageMappings();

	// First iteration to detect duplicate check validator contributions and initialize check validator
	// descriptor map
	for (IConfigurationElement checkValidatorConfigurationElement : extensionRegistry.getConfigurationElementsFor(EXTP_CHECK_VALIDATORS)) {
	try {
	if (NODE_VALIDATOR.equals(checkValidatorConfigurationElement.getName())) {
	CheckValidatorDescriptor checkValidatorDescriptor = new CheckValidatorDescriptor(checkValidatorConfigurationElement);
	String checkValidatorClassName = checkValidatorDescriptor.getClassName();
	if (checkValidatorClassNameToCheckValidatorDescriptorMap.containsKey(checkValidatorClassName)) {
	logWarning("Duplicate validator contribution found for: " + checkValidatorClassName); //$NON-NLS-1$
	continue;
	}
	checkValidatorClassNameToCheckValidatorDescriptorMap.put(checkValidatorClassName, checkValidatorDescriptor);
	} else if (NODE_EPACKAGE_MAPPING.equals(checkValidatorConfigurationElement.getName())) {
	String javaPackageName = checkValidatorConfigurationElement.getAttribute(ATTR_EOBJECT_WRAPPER_PACKAGE_NAME);
	String ePackageNsURI = checkValidatorConfigurationElement.getAttribute(ATTR_EPACKAGE_NS_URI);
	Object ePackageObject = EPackage.Registry.INSTANCE.get(ePackageNsURI);
	if (ePackageObject == null) {
	logError("Unable to find EPackage for ", ePackageNsURI); //$NON-NLS-1$
	}
	ePackageMappings.put(javaPackageName, ePackageObject);
	}
	} catch (Exception ex) {
	logError(ex);
	}
	}

	// Second iteration to register the contributed check validators with EMF's EValidator registry and check
	// catalog URI map
	for (CheckValidatorDescriptor checkValidatorDescriptor : checkValidatorClassNameToCheckValidatorDescriptorMap.values()) {
	try {
	// Create instance of contributed check validator
	ICheckValidator validator = checkValidatorDescriptor.newInstance();

	// Register check validator upon all EPackages that are affected by the former
	Set<Class<?>> classesUnderCheck = findClassesUnderCheck(validator.getClass());
	Set<EPackage> affectedEPackages = findAffectedEPackages(classesUnderCheck, ePackageMappings);
	for (EPackage affectedEPackage : affectedEPackages) {
	addValidator(affectedEPackage, validator);
	}

	URI catalogURI = checkValidatorDescriptor.getCatalogURI();
	checkValidatorToCheckCatalogURIMap.put(validator, catalogURI);
	if (catalogURI != null) {
	Set<ICheckValidator> checkValidators = checkCatalogURIToCheckValidatorsMap.get(catalogURI);
	if (checkValidators == null) {
	checkValidators = new HashSet<ICheckValidator>();
	checkCatalogURIToCheckValidatorsMap.put(catalogURI, checkValidators);
	}
	checkValidators.add(validator);
	}
	} catch (Exception ex) {
	logError(ex);
	}
	}

	// Clear temporary objects
	checkValidatorClassNameToCheckValidatorDescriptorMap.clear();
	ePackageMappings.clear();
	}
	}

	/**
	* Retrieves the classes (typically metamodel element types) from the arguments of the check validator methods that
	* are annotated with @Check.
	*
	* @param validatorClass
	* @return
	*/
	private Set<Class<?>> findClassesUnderCheck(Class<? extends ICheckValidator> validatorClass) {
	Assert.isNotNull(validatorClass);

	Set<Class<?>> classesUnderCheck = new HashSet<Class<?>>();
	Collection<Method> methods = CheckValidationUtil.getDeclaredCheckMethods(validatorClass);
	for (Method method : methods) {
	Annotation[] annotations = method.getAnnotations();
	for (Annotation annotation : annotations) {
	Class<? extends Annotation> annotationType = annotation.annotationType();
	if (annotationType.equals(Check.class)) {
	Class<?>[] parameterTypes = method.getParameterTypes();
	if (parameterTypes.length > 0) {
	classesUnderCheck.add(parameterTypes[0]);
	}
	}
	}
	}
	return classesUnderCheck;
	}

	/**
	* Retrieves the set {@link EPackage}s behind the given set of classes to be checked.
	*
	* @param classesUnderCheck
	* @return
	*/
	private Set<EPackage> findAffectedEPackages(Set<Class<?>> classesUnderCheck, EPackageMappings ePackageMappings) {
	Assert.isNotNull(classesUnderCheck);

	Set<EPackage> affectedEPackages = new HashSet<EPackage>();
	for (Class<?> classUnderCheck : classesUnderCheck) {
	EPackage ePackage = findAffectedEPackage(classUnderCheck, ePackageMappings);
	if (ePackage == null) {
	logError("Unable to find EPackage for ", classUnderCheck.getName()); //$NON-NLS-1$
	continue;
	}
	affectedEPackages.add(ePackage);
	}
	return affectedEPackages;
	}

	private EPackage findAffectedEPackage(Class<?> classUnderCheck, EPackageMappings ePackageMappings) {
	Assert.isNotNull(ePackageMappings);

	EPackage ePackage = ePackageMappings.getEPackageFor(classUnderCheck);
	if (ePackage != null) {
	return ePackage;
	}

	ePackage = EObjectUtil.findEPackage(classUnderCheck);
	if (ePackage != null) {
	ePackageMappings.put(classUnderCheck.getName(), ePackage);
	}
	return ePackage;
	}

	public void addValidator(EPackage ePackage, EValidator validator) {
	// Retrieve existing validator for given EPackage if any
	EValidator existingValidator = eValidatorRegistry.getEValidator(ePackage);

	// No validator for given EPackage so far?
	if (existingValidator == null) {
	// Register given check validator as is
	eValidatorRegistry.put(ePackage, validator);
	}
	// Existing validator being a composite validator?
	else if (existingValidator instanceof ICompositeValidator) {
	// Add given check validator as additional child validator
	((ICompositeValidator) existingValidator).addValidator(validator);
	}
	// Existing validator is an EValidator or another check validator
	else {
	// Replace existing validator by a composite validator containing existing validator and given check
	// validator as child validators
	ICompositeValidator compositeValidator = new CompositeValidator();
	compositeValidator.addValidator(existingValidator);
	compositeValidator.addValidator(validator);
	eValidatorRegistry.put(ePackage, compositeValidator);
	}
	}

	/**
	* Retrieve a check-based validator contributed through the <code>org.eclipse.sphinx.emf.check.chekvalidators</code>
	* extension point for the given package.
	*
	* @param ePackage
	* @return
	* @throws CoreException
	*/
	public EValidator getValidator(EPackage ePackage) {
	EValidator eValidator = getEValidatorRegistry().getEValidator(ePackage);
	if (eValidator instanceof ICheckValidator \|\| eValidator instanceof ICompositeValidator) {
	return eValidator;
	}
	return null;
	}

	/**
	* Returns the URI of a check catalog associated with given check validator.
	*
	* @param checkValidator
	* @return
	*/
	public URI getCheckCatalogURI(ICheckValidator checkValidator) {
	return getCheckValidatorToCheckCatalogURIMap().get(checkValidator);
	}

	public Catalog getCheckCatalog(ICheckValidator checkValidator) {
	URI checkCatalogURI = getCheckCatalogURI(checkValidator);
	if (checkCatalogURI != null) {
	return loadCheckCatalog(checkCatalogURI);
	}
	return null;
	}

	private Catalog loadCheckCatalog(URI checkCatalogURI) {
	Catalog catalog = uriToCheckCatalogMap.get(checkCatalogURI);
	if (catalog == null) {
	EObject eObject = EcoreResourceUtil.loadEObject(null, checkCatalogURI.appendFragment("/")); //$NON-NLS-1$
	if (!(eObject instanceof Catalog)) {
	throw new IllegalStateException("Unable to find the check catalog for URI '" + checkCatalogURI + "'"); //$NON-NLS-1$ //$NON-NLS-2$
	}
	catalog = (Catalog) eObject;
	uriToCheckCatalogMap.put(checkCatalogURI, catalog);
	}
	return catalog;
	}

	public Collection<Catalog> getCheckCatalogs() {
	Set<URI> allCalalogURIs = getCheckCatalogURIToCheckValidatorsMap().keySet();
	for (URI uri : allCalalogURIs) {
	if (uriToCheckCatalogMap.get(uri) == null) {
	loadCheckCatalog(uri);
	}
	}
	return uriToCheckCatalogMap.values();
	}

	public Collection<ICheckValidator> getCheckValidators() {
	return getCheckValidatorToCheckCatalogURIMap().keySet();
	}

	private void logWarning(String msgId, Object... objects) {
	logWarning(new RuntimeException(NLS.bind(msgId, objects)));
	}

	private void logWarning(Throwable throwable) {
	logger.log(StatusUtil.createWarningStatus(Activator.getDefault(), throwable));
	}

	private void logError(String msgId, Object... objects) {
	logError(new RuntimeException(NLS.bind(msgId, objects)));
	}

	private void logError(Throwable throwable) {
	logger.log(StatusUtil.createErrorStatus(Activator.getDefault(), throwable));
	}
	}