1 files changed, 276 insertions, 0 deletions
diff --git a/jpa/plugins/org.eclipse.jpt.core/src/org/eclipse/jpt/core/internal/JpaPlatformRegistry.java b/jpa/plugins/org.eclipse.jpt.core/src/org/eclipse/jpt/core/internal/JpaPlatformRegistry.java
new file mode 100644
index 0000000000..40081ca6fc
--- /dev/null
+++ b/jpa/plugins/org.eclipse.jpt.core/src/org/eclipse/jpt/core/internal/JpaPlatformRegistry.java
@@ -0,0 +1,276 @@
+/*******************************************************************************
+ * Copyright (c) 2006, 2010 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;
+
+import java.util.HashMap;
+import java.util.Map;
+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.Platform;
+import org.eclipse.jpt.core.JpaPlatform;
+import org.eclipse.jpt.core.JpaPlatformFactory;
+import org.eclipse.jpt.core.JptCorePlugin;
+import org.eclipse.jpt.utility.internal.CollectionTools;
+import org.eclipse.jpt.utility.internal.iterables.CompositeIterable;
+import org.eclipse.jpt.utility.internal.iterables.FilteringIterable;
+import org.eclipse.jpt.utility.internal.iterables.TransformationIterable;
+import org.eclipse.osgi.util.NLS;
+
+/**
+ * Singleton registry for storing all the registered JPA platform configuration
+ * elements and instantiating JPA platforms from them.
+ */
+public class JpaPlatformRegistry {
+
+	private final HashMap<String, IConfigurationElement> jpaPlatformConfigurationElements;
+
+
+	// singleton
+	private static final JpaPlatformRegistry INSTANCE = new JpaPlatformRegistry();
+
+	/**
+	 * Return the singleton.
+	 */
+	public static JpaPlatformRegistry instance() {
+		return INSTANCE;
+	}
+
+	private static final String EXTENSION_ID = "jpaPlatforms"; //$NON-NLS-1$
+	private static final String PLATFORM_ELEMENT_NAME = "jpaPlatform"; //$NON-NLS-1$
+	private static final String ID_ATTRIBUTE_NAME = "id"; //$NON-NLS-1$
+	private static final String LABEL_ATTRIBUTE_NAME = "label"; //$NON-NLS-1$
+	private static final String FACTORY_CLASS_ATTRIBUTE_NAME = "factoryClass"; //$NON-NLS-1$
+	private static final String JPA_FACET_VERSION_ATTRIBUTE_NAME = "jpaFacetVersion"; //$NON-NLS-1$
+	private static final String DEFAULT_ATTRIBUTE_NAME = "default"; //$NON-NLS-1$
+
+
+	// ********** constructor/initialization **********
+
+	/**
+	 * ensure single instance
+	 */
+	private JpaPlatformRegistry() {
+		super();
+		this.jpaPlatformConfigurationElements = this.buildJpaPlatformConfigurationElements();
+	}
+
+
+	private HashMap<String, IConfigurationElement> buildJpaPlatformConfigurationElements() {
+		HashMap<String, IConfigurationElement> configElements = new HashMap<String, IConfigurationElement>();
+		for (IConfigurationElement configElement : this.getConfigElements()) {
+			this.addConfigElementTo(configElement, configElements);
+		}
+		return configElements;
+	}
+
+	/**
+	 * Return the configuration elements from the Eclipse platform extension
+	 * registry.
+	 */
+	private Iterable<IConfigurationElement> getConfigElements() {
+		return new CompositeIterable<IConfigurationElement>(
+				new TransformationIterable<IExtension, Iterable<IConfigurationElement>>(this.getExtensions()) {
+					@Override
+					protected Iterable<IConfigurationElement> transform(IExtension extension) {
+						return CollectionTools.iterable(extension.getConfigurationElements());
+					}
+				}
+		);
+	}
+
+	private Iterable<IExtension> getExtensions() {
+		return CollectionTools.iterable(this.getExtensionPoint().getExtensions());
+	}
+
+	private IExtensionPoint getExtensionPoint() {
+		return Platform.getExtensionRegistry().getExtensionPoint(JptCorePlugin.PLUGIN_ID, EXTENSION_ID);
+	}
+
+	private void addConfigElementTo(IConfigurationElement configElement, HashMap<String, IConfigurationElement> configElements) {
+		if ( ! configElement.getName().equals(PLATFORM_ELEMENT_NAME)) {
+			return;
+		}
+		if ( ! this.configElementIsValid(configElement)) {
+			return;
+		}
+
+		String id = configElement.getAttribute(ID_ATTRIBUTE_NAME);
+		IConfigurationElement prev = configElements.put(id, configElement);
+		if (prev != null) {
+			configElements.put(id, prev);  // replace previous(?)
+			this.logDuplicatePlatform(prev, configElement, id);
+		}
+	}
+
+	/**
+	 * check *all* attributes before returning
+	 */
+	private boolean configElementIsValid(IConfigurationElement configElement) {
+		boolean valid = true;
+		if (configElement.getAttribute(ID_ATTRIBUTE_NAME) == null) {
+			this.logMissingAttribute(configElement, ID_ATTRIBUTE_NAME);
+			valid = false;
+		}
+		if (configElement.getAttribute(LABEL_ATTRIBUTE_NAME) == null) {
+			this.logMissingAttribute(configElement, LABEL_ATTRIBUTE_NAME);
+			valid = false;
+		}
+		if (configElement.getAttribute(FACTORY_CLASS_ATTRIBUTE_NAME) == null) {
+			this.logMissingAttribute(configElement, FACTORY_CLASS_ATTRIBUTE_NAME);
+			valid = false;
+		}
+		return valid;
+	}
+
+
+	// ********** public methods **********
+
+	/**
+	 * Return the IDs for the registered JPA platforms.
+	 * This does not activate any of the JPA platforms' plug-ins.
+	 */
+	public Iterable<String> getJpaPlatformIds() {
+		return this.jpaPlatformConfigurationElements.keySet();
+	}
+
+	/**
+	 * Return whether the platform id is registered
+	 */
+	public boolean containsPlatform(String platformId) {
+		return this.jpaPlatformConfigurationElements.containsKey(platformId);
+	}
+
+	/**
+	 * Return the label for the JPA platform with the specified ID.
+	 * This does not activate the JPA platform's plug-in.
+	 */
+	public String getJpaPlatformLabel(String id) {
+		return this.jpaPlatformConfigurationElements.get(id).getAttribute(LABEL_ATTRIBUTE_NAME);
+	}
+	
+	/**
+	 * Return whether the platform represented by the given id supports the specified JPA facet version.
+	 * This does not active the JPA platform's plug-in.
+	 */
+	public boolean platformSupportsJpaFacetVersion(String platformId, String jpaFacetVersion) {
+		IConfigurationElement configElement = this.jpaPlatformConfigurationElements.get(platformId);
+		return configElementSupportsJpaFacetVersion(configElement, jpaFacetVersion);
+	}
+	
+	boolean configElementSupportsJpaFacetVersion(IConfigurationElement configElement, String jpaFacetVersion) {
+		
+		// config element supports version if it explicitly sets it to that version
+		// or if it specifies no version at all
+		String ver = configElement.getAttribute(JPA_FACET_VERSION_ATTRIBUTE_NAME);
+		return (ver == null) || ver.equals(jpaFacetVersion);
+	}
+	
+	/**
+	 * Return the IDs for the registered JPA platforms that support the
+	 * specified JPA facet version.
+	 * This does not activate the JPA platforms' plug-in.
+	 */
+	public Iterable<String> getJpaPlatformIdsForJpaFacetVersion(final String jpaFacetVersion) {
+		return new TransformationIterable<IConfigurationElement, String>(this.getConfigurationElementsForJpaFacetVersion(jpaFacetVersion)) {
+				@Override
+				protected String transform(IConfigurationElement configElement) {
+					return configElement.getAttribute(ID_ATTRIBUTE_NAME);
+				}
+			};
+	}
+	
+	private Iterable<IConfigurationElement> getConfigurationElementsForJpaFacetVersion(final String jpaFacetVersion) {
+		return new FilteringIterable<IConfigurationElement>(this.jpaPlatformConfigurationElements.values()) {
+				@Override
+				protected boolean accept(IConfigurationElement configElement) {
+					return configElementSupportsJpaFacetVersion(configElement, jpaFacetVersion);
+				}
+			};
+	}
+	
+	/**
+	 * Return the ID for a JPA platform registered as a default platform.
+	 * Returns null if there are no such registered platforms.
+	 * Returns the first platform ID if there are multiple such registered platforms.
+	 */
+	public String getDefaultJpaPlatformId(String jpaFacetVersion) {
+		for (Map.Entry<String, IConfigurationElement> entry: this.jpaPlatformConfigurationElements.entrySet()) {
+			String defaultFlag = entry.getValue().getAttribute(DEFAULT_ATTRIBUTE_NAME);
+			String platformId = entry.getKey();
+			if ((defaultFlag != null) && defaultFlag.equals("true")
+					&& platformSupportsJpaFacetVersion(platformId, jpaFacetVersion)) { //$NON-NLS-1$
+				return platformId;
+			}
+		}
+		return null;
+	}
+
+	/**
+	 * Return a new JPA platform for the specified ID.
+	 * NB: This should only be called when instantiating a JPA platform
+	 * when building a new JPA project.
+	 * Unlike other registry methods, invoking this method may activate 
+	 * the plug-in.
+	 */
+	public JpaPlatform getJpaPlatform(IProject project) {
+		String id = JptCorePlugin.getJpaPlatformId(project);
+		IConfigurationElement configElement = this.jpaPlatformConfigurationElements.get(id);
+		if (configElement == null) {
+			this.log(JptCoreMessages.PLATFORM_ID_DOES_NOT_EXIST, id, project.getName());
+			return null;
+		}
+		JpaPlatformFactory platformFactory;
+		try {
+			platformFactory = (JpaPlatformFactory) configElement.createExecutableExtension(FACTORY_CLASS_ATTRIBUTE_NAME);
+		} catch (CoreException ex) {
+			this.logFailedInstantiation(configElement, ex);
+			throw new IllegalArgumentException(id);
+		}
+		return platformFactory.buildJpaPlatform(id);
+	}
+
+
+	// ********** errors **********
+
+	private void logMissingAttribute(IConfigurationElement configElement, String attributeName) {
+		this.log(JptCoreMessages.REGISTRY_MISSING_ATTRIBUTE,
+						configElement.getName(),
+						configElement.getContributor().getName(),
+						attributeName
+					);
+	}
+
+	private void logDuplicatePlatform(IConfigurationElement prevConfigElement, IConfigurationElement newConfigElement, String id) {
+		this.log(JptCoreMessages.REGISTRY_DUPLICATE,
+						prevConfigElement.getContributor().getName(),
+						newConfigElement.getContributor().getName(),
+						ID_ATTRIBUTE_NAME,
+						PLATFORM_ELEMENT_NAME,
+						id
+					);
+	}
+
+	private void logFailedInstantiation(IConfigurationElement configElement, CoreException ex) {
+		this.log(JptCoreMessages.REGISTRY_FAILED_INSTANTIATION,
+						configElement.getAttribute(FACTORY_CLASS_ATTRIBUTE_NAME),
+						configElement.getName(),
+						configElement.getContributor().getName()
+					);
+		JptCorePlugin.log(ex);
+	}
+
+	private void log(String msg, Object... bindings) {
+		JptCorePlugin.log(NLS.bind(msg, bindings));
+	}
+
+}