jpa/plugins/org.eclipse.jpt.core/src/org/eclipse/jpt/core/internal/resource/JpaResourceModelProviderManager.java - dali/webtools.dali - Git at Google

 /*******************************************************************************
  * Copyright (c) 2008 Oracle. 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:
  *     Oracle - initial API and implementation
  ******************************************************************************/
 package org.eclipse.jpt.core.internal.resource;

 import java.util.HashMap;
 import java.util.Iterator;
 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IConfigurationElement;
 import org.eclipse.core.runtime.IExtension;
 import org.eclipse.core.runtime.IExtensionPoint;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.Platform;
 import org.eclipse.core.runtime.content.IContentType;
 import org.eclipse.jpt.core.JptCorePlugin;
 import org.eclipse.jpt.core.internal.JptCoreMessages;
 import org.eclipse.jpt.core.internal.utility.PlatformTools;
 import org.eclipse.jpt.core.resource.JpaResourceModelProvider;
 import org.eclipse.jpt.core.resource.JpaResourceModelProviderFactory;
 import org.eclipse.jpt.utility.internal.CollectionTools;
 import org.eclipse.jpt.utility.internal.iterators.CompositeIterator;
 import org.eclipse.jpt.utility.internal.iterators.TransformationIterator;
 import org.eclipse.osgi.util.NLS;

 /**
  * Cache the resource model provider factories as they are requested.
  */
 public class JpaResourceModelProviderManager {

 	/**
 	 * key: file content type
 	 * value: resource model provider factory provider(!)
 	 */
 	private final HashMap<String, FactoryProvider> factoryProviders;

 	private static final String EXTENSION_ID = "resourceModelProviders"; //$NON-NLS-1$
 	private static final String EL_MODEL_PROVIDER = "modelProvider"; //$NON-NLS-1$
 	private static final String AT_FILE_CONTENT_TYPE = "fileContentType"; //$NON-NLS-1$
 	private static final String AT_FACTORY_CLASS = "factoryClass"; //$NON-NLS-1$


 	// singleton
 	private static final JpaResourceModelProviderManager INSTANCE = new JpaResourceModelProviderManager();

 	/**
 	 * Return the singleton.
 	 */
 	public static JpaResourceModelProviderManager instance() {
 		return INSTANCE;
 	}


 	// ********** construction **********

 	private JpaResourceModelProviderManager() {
 		super();
 		this.factoryProviders = this.buildFactoryProviders();
 	}

 	private HashMap<String, FactoryProvider> buildFactoryProviders() {
 		HashMap<String, FactoryProvider> providers = new HashMap<String, FactoryProvider>();
 		for (Iterator<IConfigurationElement> stream = this.configElements(); stream.hasNext(); ) {
 			this.addFactoryProviderTo(stream.next(), providers);
 		}
 		return providers;
 	}

 	/**
 	 * Return the configuration elements from the Eclipse platform extension
 	 * registry.
 	 */
 	private Iterator<IConfigurationElement> configElements() {
 		return new CompositeIterator<IConfigurationElement>(this.configElementIterators());
 	}

 	private Iterator<Iterator<IConfigurationElement>> configElementIterators() {
 		return new TransformationIterator<IExtension, Iterator<IConfigurationElement>>(this.extensions()) {
 			@Override
 			protected Iterator<IConfigurationElement> transform(IExtension extension) {
 				return CollectionTools.iterator(extension.getConfigurationElements());
 			}
 		};
 	}

 	private Iterator<IExtension> extensions() {
 		return CollectionTools.iterator(this.getExtensionPoint().getExtensions());
 	}

 	private IExtensionPoint getExtensionPoint() {
 		return Platform.getExtensionRegistry().getExtensionPoint(JptCorePlugin.PLUGIN_ID, EXTENSION_ID);
 	}

 	/**
 	 * check *all* attributes before returning;
 	 * log errors, but keep on truckin'
 	 */
 	private void addFactoryProviderTo(IConfigurationElement configElement, HashMap<String, FactoryProvider> providers) {
 		if ( ! configElement.getName().equals(EL_MODEL_PROVIDER)) {
 			return;
 		}
 		boolean missingAttribute = false;
 		String fileContentType = configElement.getAttribute(AT_FILE_CONTENT_TYPE);
 		if (fileContentType == null) {
 			logMissingAttribute(configElement, AT_FILE_CONTENT_TYPE);
 			missingAttribute = false;
 		}
 		if (configElement.getAttribute(AT_FACTORY_CLASS) == null) {
 			logMissingAttribute(configElement, AT_FACTORY_CLASS);
 			missingAttribute = false;
 		}
 		if (missingAttribute) {
 			return;
 		}
 		FactoryProvider prev = providers.get(fileContentType);
 		if (prev == null) {
 			providers.put(fileContentType, new FactoryProvider(configElement));
 		} else {
 			// first config element wins - ignore later elements
 			logDuplicateFileContentType(prev.getConfigurationElement(), configElement);
 		}
 	}


 	// ********** public API **********

 	/**
 	 * Returns a resource model provider for the specified file, based on its
 	 * content type, if there is one registered for that content type, or one
 	 * of its base content types if no resource model provider is registered
 	 * for that content type.
 	 *
 	 * @param file the file the resource model represents
 	 * @return the resource model provider for the file
 	 */
 	public JpaResourceModelProvider getModelProvider(IFile file) {
 		IProject project = file.getProject();
 		IPath path = file.getFullPath();

 		IContentType contentType = PlatformTools.getContentType(file);
 		while (contentType != null) {
 			JpaResourceModelProvider modelProvider = this.getModelProvider(project, path, contentType);
 			if (modelProvider != null) {
 				return modelProvider;
 			}
 			contentType = contentType.getBaseType();
 		}

 		return null;
 	}

 	/**
 	 * Returns a resource model provider for the specified file path of the given content type
 	 * in the given project.
 	 * @param project the project in which the file path exists
 	 * @param filePath the path of the file for which the model provider should
 	 * 	be created
 	 * @param contentType the content type for which to create a model provider
 	 * @return the model provider for the file
 	 */
 	public JpaResourceModelProvider getModelProvider(IProject project, IPath filePath, IContentType fileContentType) {
 		JpaResourceModelProviderFactory factory = this.getFactory(fileContentType);
 		return (factory == null) ? null : factory.create(project, filePath);
 	}

 	private JpaResourceModelProviderFactory getFactory(IContentType fileContentType) {
 		FactoryProvider fp = this.factoryProviders.get(fileContentType.getId());
 		return (fp == null) ? null : fp.getFactory();
 	}


 	// ********** errors **********

 	private static void logMissingAttribute(IConfigurationElement configElement, String attributeName) {
 		JptCorePlugin.log(
 			NLS.bind(
 				JptCoreMessages.RESOURCE_MODEL_PROVIDER_REGISTRY_MISSING_ATTRIBUTE,
 				new String[] {
 						configElement.getName(),
 						configElement.getContributor().getName(),
 						attributeName
 				}
 			)
 		);
 	}

 	private static void logDuplicateFileContentType(IConfigurationElement configElement1, IConfigurationElement configElement2) {
 		JptCorePlugin.log(
 			NLS.bind(
 				JptCoreMessages.RESOURCE_MODEL_PROVIDER_REGISTRY_DUPLICATE_FILE_CONTENT_TYPE,
 				new String[] {
 						configElement1.getContributor().getName(),
 						configElement2.getContributor().getName(),
 						AT_FILE_CONTENT_TYPE,
 						EL_MODEL_PROVIDER,
 						configElement1.getAttribute(AT_FILE_CONTENT_TYPE)
 				}
 			)
 		);
 	}


 	// ********** factory provider **********

 	private static class FactoryProvider {
 		private final IConfigurationElement configurationElement;
 		private JpaResourceModelProviderFactory factory;
 		private boolean factoryBuilt;  // factory can be null, so use flag

 		FactoryProvider(IConfigurationElement configurationElement) {
 			super();
 			this.configurationElement = configurationElement;
 			this.factoryBuilt = false;
 		}

 		IConfigurationElement getConfigurationElement() {
 			return this.configurationElement;
 		}

 		synchronized JpaResourceModelProviderFactory getFactory() {
 			if ( ! this.factoryBuilt) {
 				this.factoryBuilt = true;
 				this.factory = this.buildFactory();
 			}
 			return this.factory;
 		}

 		private JpaResourceModelProviderFactory buildFactory() {
 			try {
 				return (JpaResourceModelProviderFactory) this.configurationElement.createExecutableExtension(AT_FACTORY_CLASS);
 			} catch (CoreException ex) {
 				this.logFailedInstantiation(ex);
 				return null;  // returning null seems to be expected
 			}
 		}

 		private void logFailedInstantiation(CoreException ex) {
 			JptCorePlugin.log(ex);
 			JptCorePlugin.log(
 				NLS.bind(
 					JptCoreMessages.RESOURCE_MODEL_PROVIDER_REGISTRY_FAILED_INSTANTIATION,
 					new String[] {
 							this.configurationElement.getAttribute(AT_FACTORY_CLASS),
 							this.configurationElement.getName(),
 							this.configurationElement.getContributor().getName()
 					}
 				)
 			);
 		}

 	}

 }
	/*******************************************************************************
	* Copyright (c) 2008 Oracle. 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:
	* Oracle - initial API and implementation
	******************************************************************************/
	package org.eclipse.jpt.core.internal.resource;

	import java.util.HashMap;
	import java.util.Iterator;
	import org.eclipse.core.resources.IFile;
	import org.eclipse.core.resources.IProject;
	import org.eclipse.core.runtime.CoreException;
	import org.eclipse.core.runtime.IConfigurationElement;
	import org.eclipse.core.runtime.IExtension;
	import org.eclipse.core.runtime.IExtensionPoint;
	import org.eclipse.core.runtime.IPath;
	import org.eclipse.core.runtime.Platform;
	import org.eclipse.core.runtime.content.IContentType;
	import org.eclipse.jpt.core.JptCorePlugin;
	import org.eclipse.jpt.core.internal.JptCoreMessages;
	import org.eclipse.jpt.core.internal.utility.PlatformTools;
	import org.eclipse.jpt.core.resource.JpaResourceModelProvider;
	import org.eclipse.jpt.core.resource.JpaResourceModelProviderFactory;
	import org.eclipse.jpt.utility.internal.CollectionTools;
	import org.eclipse.jpt.utility.internal.iterators.CompositeIterator;
	import org.eclipse.jpt.utility.internal.iterators.TransformationIterator;
	import org.eclipse.osgi.util.NLS;

	/**
	* Cache the resource model provider factories as they are requested.
	*/
	public class JpaResourceModelProviderManager {

	/**
	* key: file content type
	* value: resource model provider factory provider(!)
	*/
	private final HashMap<String, FactoryProvider> factoryProviders;

	private static final String EXTENSION_ID = "resourceModelProviders"; //$NON-NLS-1$
	private static final String EL_MODEL_PROVIDER = "modelProvider"; //$NON-NLS-1$
	private static final String AT_FILE_CONTENT_TYPE = "fileContentType"; //$NON-NLS-1$
	private static final String AT_FACTORY_CLASS = "factoryClass"; //$NON-NLS-1$


	// singleton
	private static final JpaResourceModelProviderManager INSTANCE = new JpaResourceModelProviderManager();

	/**
	* Return the singleton.
	*/
	public static JpaResourceModelProviderManager instance() {
	return INSTANCE;
	}


	// ******** construction ********

	private JpaResourceModelProviderManager() {
	super();
	this.factoryProviders = this.buildFactoryProviders();
	}

	private HashMap<String, FactoryProvider> buildFactoryProviders() {
	HashMap<String, FactoryProvider> providers = new HashMap<String, FactoryProvider>();
	for (Iterator<IConfigurationElement> stream = this.configElements(); stream.hasNext(); ) {
	this.addFactoryProviderTo(stream.next(), providers);
	}
	return providers;
	}

	/**
	* Return the configuration elements from the Eclipse platform extension
	* registry.
	*/
	private Iterator<IConfigurationElement> configElements() {
	return new CompositeIterator<IConfigurationElement>(this.configElementIterators());
	}

	private Iterator<Iterator<IConfigurationElement>> configElementIterators() {
	return new TransformationIterator<IExtension, Iterator<IConfigurationElement>>(this.extensions()) {
	@Override
	protected Iterator<IConfigurationElement> transform(IExtension extension) {
	return CollectionTools.iterator(extension.getConfigurationElements());
	}
	};
	}

	private Iterator<IExtension> extensions() {
	return CollectionTools.iterator(this.getExtensionPoint().getExtensions());
	}

	private IExtensionPoint getExtensionPoint() {
	return Platform.getExtensionRegistry().getExtensionPoint(JptCorePlugin.PLUGIN_ID, EXTENSION_ID);
	}

	/**
	* check all attributes before returning;
	* log errors, but keep on truckin'
	*/
	private void addFactoryProviderTo(IConfigurationElement configElement, HashMap<String, FactoryProvider> providers) {
	if ( ! configElement.getName().equals(EL_MODEL_PROVIDER)) {
	return;
	}
	boolean missingAttribute = false;
	String fileContentType = configElement.getAttribute(AT_FILE_CONTENT_TYPE);
	if (fileContentType == null) {
	logMissingAttribute(configElement, AT_FILE_CONTENT_TYPE);
	missingAttribute = false;
	}
	if (configElement.getAttribute(AT_FACTORY_CLASS) == null) {
	logMissingAttribute(configElement, AT_FACTORY_CLASS);
	missingAttribute = false;
	}
	if (missingAttribute) {
	return;
	}
	FactoryProvider prev = providers.get(fileContentType);
	if (prev == null) {
	providers.put(fileContentType, new FactoryProvider(configElement));
	} else {
	// first config element wins - ignore later elements
	logDuplicateFileContentType(prev.getConfigurationElement(), configElement);
	}
	}


	// ******** public API ********

	/**
	* Returns a resource model provider for the specified file, based on its
	* content type, if there is one registered for that content type, or one
	* of its base content types if no resource model provider is registered
	* for that content type.
	*
	* @param file the file the resource model represents
	* @return the resource model provider for the file
	*/
	public JpaResourceModelProvider getModelProvider(IFile file) {
	IProject project = file.getProject();
	IPath path = file.getFullPath();

	IContentType contentType = PlatformTools.getContentType(file);
	while (contentType != null) {
	JpaResourceModelProvider modelProvider = this.getModelProvider(project, path, contentType);
	if (modelProvider != null) {
	return modelProvider;
	}
	contentType = contentType.getBaseType();
	}

	return null;
	}

	/**
	* Returns a resource model provider for the specified file path of the given content type
	* in the given project.
	* @param project the project in which the file path exists
	* @param filePath the path of the file for which the model provider should
	* be created
	* @param contentType the content type for which to create a model provider
	* @return the model provider for the file
	*/
	public JpaResourceModelProvider getModelProvider(IProject project, IPath filePath, IContentType fileContentType) {
	JpaResourceModelProviderFactory factory = this.getFactory(fileContentType);
	return (factory == null) ? null : factory.create(project, filePath);
	}

	private JpaResourceModelProviderFactory getFactory(IContentType fileContentType) {
	FactoryProvider fp = this.factoryProviders.get(fileContentType.getId());
	return (fp == null) ? null : fp.getFactory();
	}


	// ******** errors ********

	private static void logMissingAttribute(IConfigurationElement configElement, String attributeName) {
	JptCorePlugin.log(
	NLS.bind(
	JptCoreMessages.RESOURCE_MODEL_PROVIDER_REGISTRY_MISSING_ATTRIBUTE,
	new String[] {
	configElement.getName(),
	configElement.getContributor().getName(),
	attributeName
	}
	)
	);
	}

	private static void logDuplicateFileContentType(IConfigurationElement configElement1, IConfigurationElement configElement2) {
	JptCorePlugin.log(
	NLS.bind(
	JptCoreMessages.RESOURCE_MODEL_PROVIDER_REGISTRY_DUPLICATE_FILE_CONTENT_TYPE,
	new String[] {
	configElement1.getContributor().getName(),
	configElement2.getContributor().getName(),
	AT_FILE_CONTENT_TYPE,
	EL_MODEL_PROVIDER,
	configElement1.getAttribute(AT_FILE_CONTENT_TYPE)
	}
	)
	);
	}


	// ******** factory provider ********

	private static class FactoryProvider {
	private final IConfigurationElement configurationElement;
	private JpaResourceModelProviderFactory factory;
	private boolean factoryBuilt; // factory can be null, so use flag

	FactoryProvider(IConfigurationElement configurationElement) {
	super();
	this.configurationElement = configurationElement;
	this.factoryBuilt = false;
	}

	IConfigurationElement getConfigurationElement() {
	return this.configurationElement;
	}

	synchronized JpaResourceModelProviderFactory getFactory() {
	if ( ! this.factoryBuilt) {
	this.factoryBuilt = true;
	this.factory = this.buildFactory();
	}
	return this.factory;
	}

	private JpaResourceModelProviderFactory buildFactory() {
	try {
	return (JpaResourceModelProviderFactory) this.configurationElement.createExecutableExtension(AT_FACTORY_CLASS);
	} catch (CoreException ex) {
	this.logFailedInstantiation(ex);
	return null; // returning null seems to be expected
	}
	}

	private void logFailedInstantiation(CoreException ex) {
	JptCorePlugin.log(ex);
	JptCorePlugin.log(
	NLS.bind(
	JptCoreMessages.RESOURCE_MODEL_PROVIDER_REGISTRY_FAILED_INSTANTIATION,
	new String[] {
	this.configurationElement.getAttribute(AT_FACTORY_CLASS),
	this.configurationElement.getName(),
	this.configurationElement.getContributor().getName()
	}
	)
	);
	}

	}

	}