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

 /*******************************************************************************
 * Copyright (c) 2012 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.jpa.core.internal.prefs;

 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.ProjectScope;
 import org.eclipse.core.runtime.IProgressMonitor;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.core.runtime.jobs.Job;
 import org.eclipse.core.runtime.preferences.DefaultScope;
 import org.eclipse.core.runtime.preferences.IEclipsePreferences;
 import org.eclipse.core.runtime.preferences.IScopeContext;
 import org.eclipse.core.runtime.preferences.InstanceScope;
 import org.eclipse.jpt.common.utility.internal.StringTools;
 import org.eclipse.jpt.jpa.core.JpaFacet;
 import org.eclipse.jpt.jpa.core.JptJpaCorePlugin;
 import org.eclipse.jpt.jpa.core.internal.JptCoreMessages;
 import org.eclipse.jpt.jpa.core.internal.platform.JpaPlatformManagerImpl;
 import org.eclipse.jpt.jpa.core.platform.GenericPlatform;
 import org.eclipse.jpt.jpa.core.platform.JpaPlatformDescription;
 import org.eclipse.osgi.util.NLS;
 import org.osgi.service.prefs.BackingStoreException;

 /**
  *  JptPreferencesManager
  */
 public class JpaPreferencesManager
 {
 	private final IProject project;

 	private static volatile boolean flushPreferences = true;

 	// ********** public constants **********

 	/**
 	 * The key for storing a JPA project's platform ID in the Eclipse
 	 * project's preferences.
 	 */
 	protected static final String JPA_PLATFORM_PREF_KEY = JptJpaCorePlugin.LEGACY_PLUGIN_ID_ + "platform";  //$NON-NLS-1$

 	/**
 	 * The old key for storing the default JPA platform ID in the workspace preferences.
 	 * @deprecated  As of version 2.3.  Instead use {@link #DEFAULT_JPA_PLATFORM_1_0_PREF_KEY} or
 	 * 		{@link #DEFAULT_JPA_PLATFORM_2_0_PREF_KEY}
 	 */
 	@Deprecated
 	public static final String DEFAULT_JPA_PLATFORM_PREF_KEY = "defaultJpaPlatform"; //$NON-NLS-1$

 	/**
 	 * The key for storing the default JPA platform ID for JPA 1.0 in the workspace preferences.
 	 */
 	public static final String DEFAULT_JPA_PLATFORM_1_0_PREF_KEY =
 			DEFAULT_JPA_PLATFORM_PREF_KEY + "_" + JpaFacet.VERSION_1_0.getVersionString(); //$NON-NLS-1$

 	/**
 	 * The key for storing the default JPA platform ID for JPA 2.0 in the workspace preferences.
 	 */
 	public static final String DEFAULT_JPA_PLATFORM_2_0_PREF_KEY =
 			DEFAULT_JPA_PLATFORM_PREF_KEY + "_" + JpaFacet.VERSION_2_0.getVersionString(); //$NON-NLS-1$

 	/**
 	 * The key for storing a JPA project's "discover" flag in the Eclipse
 	 * project's preferences.
 	 */
 	public static final String DISCOVER_ANNOTATED_CLASSES = JptJpaCorePlugin.PLUGIN_ID_ + "discoverAnnotatedClasses";  //$NON-NLS-1$

 	//bug 354780 - made the mistake of changing the project metadata in the 3.0 release
 	protected static final String LEGACY_DISCOVER_ANNOTATED_CLASSES = JptJpaCorePlugin.LEGACY_PLUGIN_ID_ + "discoverAnnotatedClasses";  //$NON-NLS-1$

 	/**
 	 * The key for storing the name of a JPA project's metamodel source folder
 	 * in the Eclipse project's preferences.
 	 */
 	public static final String METAMODEL_SOURCE_FOLDER_NAME = JptJpaCorePlugin.PLUGIN_ID_ + "metamodelSourceFolderName";  //$NON-NLS-1$

 	//bug 354780 - made the mistake of changing the project metadata in the 3.0 release
 	protected static final String LEGACY_METAMODEL_SOURCE_FOLDER_NAME = JptJpaCorePlugin.LEGACY_PLUGIN_ID_ + "metamodelSourceFolderName";  //$NON-NLS-1$


 	// ********** static methods **************************************************

 	public static void clearWorkspacePreferences() throws BackingStoreException {
 		getWorkspacePreferences().clear();
 	}

 	// ********** preferences **********

 	/**
 	 * Return the Dali preferences for the specified context.
 	 */
 	private static IEclipsePreferences getPreferences(IScopeContext context) {
 		return context.getNode(JptJpaCorePlugin.LEGACY_PLUGIN_ID);
 	}

 	/**
 	 * Return the Dali preferences for the current workspace instance.
 	 */
 	public static IEclipsePreferences getWorkspacePreferences() {
 		return getPreferences(InstanceScope.INSTANCE);
 	}

 	/**
 	 * Return the default Dali preferences
 	 * @see JpaPreferenceInitializer
 	 */
 	 public static IEclipsePreferences getDefaultPreferences() {
 		return getPreferences(DefaultScope.INSTANCE);
 	}

 	public static void initializeDefaultPreferences() {
 		IEclipsePreferences node = getDefaultPreferences();

 		// default JPA platforms
 		JpaPlatformDescription defaultPlatform_1_0 =
 				JpaPlatformManagerImpl.instance().getDefaultJpaPlatform(JpaFacet.VERSION_1_0);
 		if (defaultPlatform_1_0 == null) {
 			defaultPlatform_1_0 = GenericPlatform.VERSION_1_0;
 		}
 		node.put(DEFAULT_JPA_PLATFORM_1_0_PREF_KEY, defaultPlatform_1_0.getId());

 		JpaPlatformDescription defaultPlatform_2_0 =
 				JpaPlatformManagerImpl.instance().getDefaultJpaPlatform(JpaFacet.VERSION_2_0);
 		if (defaultPlatform_2_0 == null) {
 			defaultPlatform_2_0 = GenericPlatform.VERSION_2_0;
 		}
 		node.put(DEFAULT_JPA_PLATFORM_2_0_PREF_KEY, defaultPlatform_2_0.getId());
 	}

 	// ********** workspace preference **********

 	protected static String getWorkspacePreference(String key, String defaultValue) {
 		String value = getWorkspacePreferences().get(key, defaultValue);
 		return (StringTools.stringIsEmpty(value)) ? defaultValue : value;
 	}

 	protected static String getWorkspacePreference(String key) {
 		return getWorkspacePreferences().get(key, null);
 	}

 	public static void setWorkspacePreference(String key, String value) {
 		IEclipsePreferences wkspPrefs = getWorkspacePreferences();
 		if(value == null) {
 			wkspPrefs.remove(key);
 		}
 		else {
 			wkspPrefs.put(key, value);
 		}
 		flush(wkspPrefs);
 	}

 	protected static boolean getWorkspacePreference(String key, boolean defaultBooleanValue) {
 		return getWorkspacePreferences().getBoolean(key, defaultBooleanValue);
 	}

 	public static void setWorkspacePreference(String key, boolean booleanValue) {
 		IEclipsePreferences wkspPrefs = getWorkspacePreferences();
 		wkspPrefs.putBoolean(key, booleanValue);
 		flush(wkspPrefs);
 	}

 	public static void removeWorkspacePreference(String key) {
 		IEclipsePreferences wkspPrefs = getWorkspacePreferences();
 		wkspPrefs.remove(key);
 		flush(wkspPrefs);
 	}

 	// ********** private static methods **********

 	/**
 	 * This method is called (via reflection) when the test plug-in is loaded.
 	 * The preferences end up getting flushed after the test case has deleted
 	 * its project, resulting in resource exceptions in the log, e.g.
 	 * <pre>
 	 *     Resource '/JpaProjectManagerTests' is not open.
 	 * </pre>
 	 * See <code>JptJpaCoreTestsPlugin.start(BundleContext)</code>
 	 */
 	@SuppressWarnings("unused")
 	private static void doNotFlushPreferences() {
 		flushPreferences = false;
 	}

 	/**
 	 * Flush preferences in an asynchronous Job because the flush request will
 	 * trigger a lock on the project, which can cause us some deadlocks (e.g.
 	 * when deleting the metamodel source folder).
 	 * Note: the flush will also remove the prefs node if it is empty
 	 */
 	private static void flush(IEclipsePreferences prefs) {
 		if (flushPreferences) {
 			new PreferencesFlushJob(prefs).schedule();
 		}
 	}

 	private static class PreferencesFlushJob extends Job {
 		private final IEclipsePreferences prefs;
 		PreferencesFlushJob(IEclipsePreferences prefs) {
 			super(NLS.bind(JptCoreMessages.PREFERENCES_FLUSH_JOB_NAME, prefs.absolutePath()));
 			this.prefs = prefs;
 		}
 		@Override
 		protected IStatus run(IProgressMonitor monitor) {
 			try {
 				this.prefs.flush();
 			}
 			catch(BackingStoreException ex) {
 				JptJpaCorePlugin.log(ex);
 			}
 			return Status.OK_STATUS;
 		}
 	}

 	// ********** implementation **************************************************

 	public JpaPreferencesManager(IProject project) {
 		if(project == null) {
 			throw new RuntimeException("Project is null"); 	//$NON-NLS-1$
 		}
 		this.project = project;
 	}

 	// ********** query **********

 	protected String getPreference(String key) {
 		String preferenceValue = this.getProjectPreference(key);

 		// check workspace preferences if not a project preference
 		if(preferenceValue == null) {
 			preferenceValue = getWorkspacePreference(key);
 		}
 		return preferenceValue;
 	}

 	protected String getPreference(String key, String defaultValue) {
 		String preferenceValue = this.getPreference(key);
 		if(StringTools.stringIsEmpty(preferenceValue)) {
 			return defaultValue;
 		}
 		return preferenceValue;
 	}

 	// ********** preferences **********

 	/**
 	 * Return the Dali preferences for the specified Eclipse project.
 	 */
 	protected IEclipsePreferences getProjectPreferences() {
 		return getPreferences(new ProjectScope(this.project));
 	}

 	/**
 	 * Clears the project of JPA-specific preferences
 	 */
 	public void clearProjectPreferences() {
 		this.clearProjectPreferences(
 				JPA_PLATFORM_PREF_KEY,
 				DISCOVER_ANNOTATED_CLASSES,
 				METAMODEL_SOURCE_FOLDER_NAME,
 				LEGACY_DISCOVER_ANNOTATED_CLASSES,
 				LEGACY_METAMODEL_SOURCE_FOLDER_NAME);
 	}

 	/**
 	 * Clears the specified preferences
 	 */
 	public void clearProjectPreferences(String ... preferenceKeys) {
 		IEclipsePreferences projectPrefs = this.getProjectPreferences();
 		for(String preferenceKey : preferenceKeys) {
 			projectPrefs.remove(preferenceKey);
 		}
 		flush(projectPrefs);
 	}

 	// ********** project preference **********

 	protected String getProjectPreference(String key, String defaultValue) {
 		String value = this.getProjectPreferences().get(key, defaultValue);
 		return (StringTools.stringIsEmpty(value)) ? defaultValue : value;
 	}

 	protected String getProjectPreference(String key) {
 		return this.getProjectPreferences().get(key, null);
 	}

 	protected void setProjectPreference(String key, String value) {
 		IEclipsePreferences projectPrefs = this.getProjectPreferences();
 		if(value == null) {
 			projectPrefs.remove(key);
 		}
 		else {
 			projectPrefs.put(key, value);
 		}
 		flush(projectPrefs);
 	}

 	protected boolean getProjectPreference(String key, boolean defaultBooleanValue) {
 		return this.getProjectPreferences().getBoolean(key, defaultBooleanValue);
 	}

 	protected void setProjectPreference(String key, boolean booleanValue) {
 		IEclipsePreferences projectPrefs = this.getProjectPreferences();
 		projectPrefs.putBoolean(key, booleanValue);
 		flush(projectPrefs);
 	}

 	protected void removeProjectPreference(String key) {
 		IEclipsePreferences projectPrefs = this.getProjectPreferences();
 		projectPrefs.remove(key);
 		flush(projectPrefs);
 	}

 	// ********** getters/setters *********

 	/**
 	 * Return the JPA platform ID associated with the specified Eclipse project.
 	 */
 	public String getJpaPlatformId() {
 		return this.getProjectPreference(JPA_PLATFORM_PREF_KEY, GenericPlatform.VERSION_1_0.getId());
 	}

 	/**
 	 * Set the JPA platform ID associated with the specified Eclipse project.
 	 */
 	public void setJpaPlatformId(String jpaPlatformId) {
 		this.setProjectPreference(JPA_PLATFORM_PREF_KEY, jpaPlatformId);
 	}

 	/**
 	 * Return the JPA "discover" flag associated with the specified
 	 * Eclipse project.
 	 */
 	public boolean getDiscoverAnnotatedClasses() {
 		if (this.getProjectPreference(DISCOVER_ANNOTATED_CLASSES, null) != null) {
 			return this.getProjectPreference(DISCOVER_ANNOTATED_CLASSES, false);
 		}
 		//bug 354780 - made the mistake of changing the project metadata in the 3.0 release
 		return this.getProjectPreference(LEGACY_DISCOVER_ANNOTATED_CLASSES, false);
 	}

 	 /**
 	  * Set the JPA "discover" flag associated with the specified
 	 * Eclipse project.
 	 */
 	public void setDiscoverAnnotatedClasses(boolean discoverAnnotatedClasses) {
 		this.setProjectPreference(DISCOVER_ANNOTATED_CLASSES, discoverAnnotatedClasses);
 	}

 	/**
 	 * Return the name of the metamodel source folder associated with the
 	 * specified Eclipse project.
 	 */
 	public String getMetamodelSourceFolderName() {
 		String metamodelSourceFolderName = this.getProjectPreference(METAMODEL_SOURCE_FOLDER_NAME, null);
 		if (metamodelSourceFolderName != null) {
 			return metamodelSourceFolderName;
 		}
 		//bug 354780 - made the mistake of changing the project metadata in the 3.0 release
 		return this.getProjectPreference(LEGACY_METAMODEL_SOURCE_FOLDER_NAME, null);
 	}

 	/**
 	 * Set the name of the metamodel source folder associated with the
 	 * specified Eclipse project.
 	 */
 	public void setMetamodelSourceFolderName(String metamodelSourceFolderName) {
 		this.setProjectPreference(METAMODEL_SOURCE_FOLDER_NAME, metamodelSourceFolderName);
 		//bug 354780 - made the mistake of changing the project metadata in the 3.0 release.
 		//make sure legacy setting is removed when turning off metamodel gen, if we don't then
 		//there will be no way to turn off meatamodel gen without sacrificing backwards compatibility
 		if(metamodelSourceFolderName == null) {
 			this.setProjectPreference(LEGACY_METAMODEL_SOURCE_FOLDER_NAME, null);
 		}
 	}

 	// ********** protected methods **********

 	protected IProject getProject() {
 		return this.project;
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2012 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.jpa.core.internal.prefs;

	import org.eclipse.core.resources.IProject;
	import org.eclipse.core.resources.ProjectScope;
	import org.eclipse.core.runtime.IProgressMonitor;
	import org.eclipse.core.runtime.IStatus;
	import org.eclipse.core.runtime.Status;
	import org.eclipse.core.runtime.jobs.Job;
	import org.eclipse.core.runtime.preferences.DefaultScope;
	import org.eclipse.core.runtime.preferences.IEclipsePreferences;
	import org.eclipse.core.runtime.preferences.IScopeContext;
	import org.eclipse.core.runtime.preferences.InstanceScope;
	import org.eclipse.jpt.common.utility.internal.StringTools;
	import org.eclipse.jpt.jpa.core.JpaFacet;
	import org.eclipse.jpt.jpa.core.JptJpaCorePlugin;
	import org.eclipse.jpt.jpa.core.internal.JptCoreMessages;
	import org.eclipse.jpt.jpa.core.internal.platform.JpaPlatformManagerImpl;
	import org.eclipse.jpt.jpa.core.platform.GenericPlatform;
	import org.eclipse.jpt.jpa.core.platform.JpaPlatformDescription;
	import org.eclipse.osgi.util.NLS;
	import org.osgi.service.prefs.BackingStoreException;

	/**
	* JptPreferencesManager
	*/
	public class JpaPreferencesManager
	{
	private final IProject project;

	private static volatile boolean flushPreferences = true;

	// ******** public constants ********

	/**
	* The key for storing a JPA project's platform ID in the Eclipse
	* project's preferences.
	*/
	protected static final String JPA_PLATFORM_PREF_KEY = JptJpaCorePlugin.LEGACY_PLUGIN_ID_ + "platform"; //$NON-NLS-1$

	/**
	* The old key for storing the default JPA platform ID in the workspace preferences.
	* @deprecated As of version 2.3. Instead use {@link #DEFAULT_JPA_PLATFORM_1_0_PREF_KEY} or
	* {@link #DEFAULT_JPA_PLATFORM_2_0_PREF_KEY}
	*/
	@Deprecated
	public static final String DEFAULT_JPA_PLATFORM_PREF_KEY = "defaultJpaPlatform"; //$NON-NLS-1$

	/**
	* The key for storing the default JPA platform ID for JPA 1.0 in the workspace preferences.
	*/
	public static final String DEFAULT_JPA_PLATFORM_1_0_PREF_KEY =
	DEFAULT_JPA_PLATFORM_PREF_KEY + "_" + JpaFacet.VERSION_1_0.getVersionString(); //$NON-NLS-1$

	/**
	* The key for storing the default JPA platform ID for JPA 2.0 in the workspace preferences.
	*/
	public static final String DEFAULT_JPA_PLATFORM_2_0_PREF_KEY =
	DEFAULT_JPA_PLATFORM_PREF_KEY + "_" + JpaFacet.VERSION_2_0.getVersionString(); //$NON-NLS-1$

	/**
	* The key for storing a JPA project's "discover" flag in the Eclipse
	* project's preferences.
	*/
	public static final String DISCOVER_ANNOTATED_CLASSES = JptJpaCorePlugin.PLUGIN_ID_ + "discoverAnnotatedClasses"; //$NON-NLS-1$

	//bug 354780 - made the mistake of changing the project metadata in the 3.0 release
	protected static final String LEGACY_DISCOVER_ANNOTATED_CLASSES = JptJpaCorePlugin.LEGACY_PLUGIN_ID_ + "discoverAnnotatedClasses"; //$NON-NLS-1$

	/**
	* The key for storing the name of a JPA project's metamodel source folder
	* in the Eclipse project's preferences.
	*/
	public static final String METAMODEL_SOURCE_FOLDER_NAME = JptJpaCorePlugin.PLUGIN_ID_ + "metamodelSourceFolderName"; //$NON-NLS-1$

	//bug 354780 - made the mistake of changing the project metadata in the 3.0 release
	protected static final String LEGACY_METAMODEL_SOURCE_FOLDER_NAME = JptJpaCorePlugin.LEGACY_PLUGIN_ID_ + "metamodelSourceFolderName"; //$NON-NLS-1$


	// ******** static methods ************************************************

	public static void clearWorkspacePreferences() throws BackingStoreException {
	getWorkspacePreferences().clear();
	}

	// ******** preferences ********

	/**
	* Return the Dali preferences for the specified context.
	*/
	private static IEclipsePreferences getPreferences(IScopeContext context) {
	return context.getNode(JptJpaCorePlugin.LEGACY_PLUGIN_ID);
	}

	/**
	* Return the Dali preferences for the current workspace instance.
	*/
	public static IEclipsePreferences getWorkspacePreferences() {
	return getPreferences(InstanceScope.INSTANCE);
	}

	/**
	* Return the default Dali preferences
	* @see JpaPreferenceInitializer
	*/
	public static IEclipsePreferences getDefaultPreferences() {
	return getPreferences(DefaultScope.INSTANCE);
	}

	public static void initializeDefaultPreferences() {
	IEclipsePreferences node = getDefaultPreferences();

	// default JPA platforms
	JpaPlatformDescription defaultPlatform_1_0 =
	JpaPlatformManagerImpl.instance().getDefaultJpaPlatform(JpaFacet.VERSION_1_0);
	if (defaultPlatform_1_0 == null) {
	defaultPlatform_1_0 = GenericPlatform.VERSION_1_0;
	}
	node.put(DEFAULT_JPA_PLATFORM_1_0_PREF_KEY, defaultPlatform_1_0.getId());

	JpaPlatformDescription defaultPlatform_2_0 =
	JpaPlatformManagerImpl.instance().getDefaultJpaPlatform(JpaFacet.VERSION_2_0);
	if (defaultPlatform_2_0 == null) {
	defaultPlatform_2_0 = GenericPlatform.VERSION_2_0;
	}
	node.put(DEFAULT_JPA_PLATFORM_2_0_PREF_KEY, defaultPlatform_2_0.getId());
	}

	// ******** workspace preference ********

	protected static String getWorkspacePreference(String key, String defaultValue) {
	String value = getWorkspacePreferences().get(key, defaultValue);
	return (StringTools.stringIsEmpty(value)) ? defaultValue : value;
	}

	protected static String getWorkspacePreference(String key) {
	return getWorkspacePreferences().get(key, null);
	}

	public static void setWorkspacePreference(String key, String value) {
	IEclipsePreferences wkspPrefs = getWorkspacePreferences();
	if(value == null) {
	wkspPrefs.remove(key);
	}
	else {
	wkspPrefs.put(key, value);
	}
	flush(wkspPrefs);
	}

	protected static boolean getWorkspacePreference(String key, boolean defaultBooleanValue) {
	return getWorkspacePreferences().getBoolean(key, defaultBooleanValue);
	}

	public static void setWorkspacePreference(String key, boolean booleanValue) {
	IEclipsePreferences wkspPrefs = getWorkspacePreferences();
	wkspPrefs.putBoolean(key, booleanValue);
	flush(wkspPrefs);
	}

	public static void removeWorkspacePreference(String key) {
	IEclipsePreferences wkspPrefs = getWorkspacePreferences();
	wkspPrefs.remove(key);
	flush(wkspPrefs);
	}

	// ******** private static methods ********

	/**
	* This method is called (via reflection) when the test plug-in is loaded.
	* The preferences end up getting flushed after the test case has deleted
	* its project, resulting in resource exceptions in the log, e.g.
	* <pre>
	* Resource '/JpaProjectManagerTests' is not open.
	* </pre>
	* See <code>JptJpaCoreTestsPlugin.start(BundleContext)</code>
	*/
	@SuppressWarnings("unused")
	private static void doNotFlushPreferences() {
	flushPreferences = false;
	}

	/**
	* Flush preferences in an asynchronous Job because the flush request will
	* trigger a lock on the project, which can cause us some deadlocks (e.g.
	* when deleting the metamodel source folder).
	* Note: the flush will also remove the prefs node if it is empty
	*/
	private static void flush(IEclipsePreferences prefs) {
	if (flushPreferences) {
	new PreferencesFlushJob(prefs).schedule();
	}
	}

	private static class PreferencesFlushJob extends Job {
	private final IEclipsePreferences prefs;
	PreferencesFlushJob(IEclipsePreferences prefs) {
	super(NLS.bind(JptCoreMessages.PREFERENCES_FLUSH_JOB_NAME, prefs.absolutePath()));
	this.prefs = prefs;
	}
	@Override
	protected IStatus run(IProgressMonitor monitor) {
	try {
	this.prefs.flush();
	}
	catch(BackingStoreException ex) {
	JptJpaCorePlugin.log(ex);
	}
	return Status.OK_STATUS;
	}
	}

	// ******** implementation ************************************************

	public JpaPreferencesManager(IProject project) {
	if(project == null) {
	throw new RuntimeException("Project is null"); //$NON-NLS-1$
	}
	this.project = project;
	}

	// ******** query ********

	protected String getPreference(String key) {
	String preferenceValue = this.getProjectPreference(key);

	// check workspace preferences if not a project preference
	if(preferenceValue == null) {
	preferenceValue = getWorkspacePreference(key);
	}
	return preferenceValue;
	}

	protected String getPreference(String key, String defaultValue) {
	String preferenceValue = this.getPreference(key);
	if(StringTools.stringIsEmpty(preferenceValue)) {
	return defaultValue;
	}
	return preferenceValue;
	}

	// ******** preferences ********

	/**
	* Return the Dali preferences for the specified Eclipse project.
	*/
	protected IEclipsePreferences getProjectPreferences() {
	return getPreferences(new ProjectScope(this.project));
	}

	/**
	* Clears the project of JPA-specific preferences
	*/
	public void clearProjectPreferences() {
	this.clearProjectPreferences(
	JPA_PLATFORM_PREF_KEY,
	DISCOVER_ANNOTATED_CLASSES,
	METAMODEL_SOURCE_FOLDER_NAME,
	LEGACY_DISCOVER_ANNOTATED_CLASSES,
	LEGACY_METAMODEL_SOURCE_FOLDER_NAME);
	}

	/**
	* Clears the specified preferences
	*/
	public void clearProjectPreferences(String ... preferenceKeys) {
	IEclipsePreferences projectPrefs = this.getProjectPreferences();
	for(String preferenceKey : preferenceKeys) {
	projectPrefs.remove(preferenceKey);
	}
	flush(projectPrefs);
	}

	// ******** project preference ********

	protected String getProjectPreference(String key, String defaultValue) {
	String value = this.getProjectPreferences().get(key, defaultValue);
	return (StringTools.stringIsEmpty(value)) ? defaultValue : value;
	}

	protected String getProjectPreference(String key) {
	return this.getProjectPreferences().get(key, null);
	}

	protected void setProjectPreference(String key, String value) {
	IEclipsePreferences projectPrefs = this.getProjectPreferences();
	if(value == null) {
	projectPrefs.remove(key);
	}
	else {
	projectPrefs.put(key, value);
	}
	flush(projectPrefs);
	}

	protected boolean getProjectPreference(String key, boolean defaultBooleanValue) {
	return this.getProjectPreferences().getBoolean(key, defaultBooleanValue);
	}

	protected void setProjectPreference(String key, boolean booleanValue) {
	IEclipsePreferences projectPrefs = this.getProjectPreferences();
	projectPrefs.putBoolean(key, booleanValue);
	flush(projectPrefs);
	}

	protected void removeProjectPreference(String key) {
	IEclipsePreferences projectPrefs = this.getProjectPreferences();
	projectPrefs.remove(key);
	flush(projectPrefs);
	}

	// ******** getters/setters *******

	/**
	* Return the JPA platform ID associated with the specified Eclipse project.
	*/
	public String getJpaPlatformId() {
	return this.getProjectPreference(JPA_PLATFORM_PREF_KEY, GenericPlatform.VERSION_1_0.getId());
	}

	/**
	* Set the JPA platform ID associated with the specified Eclipse project.
	*/
	public void setJpaPlatformId(String jpaPlatformId) {
	this.setProjectPreference(JPA_PLATFORM_PREF_KEY, jpaPlatformId);
	}

	/**
	* Return the JPA "discover" flag associated with the specified
	* Eclipse project.
	*/
	public boolean getDiscoverAnnotatedClasses() {
	if (this.getProjectPreference(DISCOVER_ANNOTATED_CLASSES, null) != null) {
	return this.getProjectPreference(DISCOVER_ANNOTATED_CLASSES, false);
	}
	//bug 354780 - made the mistake of changing the project metadata in the 3.0 release
	return this.getProjectPreference(LEGACY_DISCOVER_ANNOTATED_CLASSES, false);
	}

	/**
	* Set the JPA "discover" flag associated with the specified
	* Eclipse project.
	*/
	public void setDiscoverAnnotatedClasses(boolean discoverAnnotatedClasses) {
	this.setProjectPreference(DISCOVER_ANNOTATED_CLASSES, discoverAnnotatedClasses);
	}

	/**
	* Return the name of the metamodel source folder associated with the
	* specified Eclipse project.
	*/
	public String getMetamodelSourceFolderName() {
	String metamodelSourceFolderName = this.getProjectPreference(METAMODEL_SOURCE_FOLDER_NAME, null);
	if (metamodelSourceFolderName != null) {
	return metamodelSourceFolderName;
	}
	//bug 354780 - made the mistake of changing the project metadata in the 3.0 release
	return this.getProjectPreference(LEGACY_METAMODEL_SOURCE_FOLDER_NAME, null);
	}

	/**
	* Set the name of the metamodel source folder associated with the
	* specified Eclipse project.
	*/
	public void setMetamodelSourceFolderName(String metamodelSourceFolderName) {
	this.setProjectPreference(METAMODEL_SOURCE_FOLDER_NAME, metamodelSourceFolderName);
	//bug 354780 - made the mistake of changing the project metadata in the 3.0 release.
	//make sure legacy setting is removed when turning off metamodel gen, if we don't then
	//there will be no way to turn off meatamodel gen without sacrificing backwards compatibility
	if(metamodelSourceFolderName == null) {
	this.setProjectPreference(LEGACY_METAMODEL_SOURCE_FOLDER_NAME, null);
	}
	}

	// ******** protected methods ********

	protected IProject getProject() {
	return this.project;
	}
	}