update/org.eclipse.update.core/src/org/eclipse/update/core/model/ModelObject.java - platform/eclipse.platform - Git at Google

 /*******************************************************************************
  *  Copyright (c) 2000, 2010 IBM Corporation and others.
  *  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:
  *     IBM Corporation - initial API and implementation
  *******************************************************************************/
 package org.eclipse.update.core.model;

 import java.lang.reflect.Array;
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLClassLoader;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 import java.util.MissingResourceException;
 import java.util.ResourceBundle;
 import java.util.Set;

 import org.eclipse.core.runtime.Assert;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.Path;
 import org.eclipse.core.runtime.PlatformObject;
 import org.eclipse.update.core.Feature;
 import org.eclipse.update.core.SiteManager;
 import org.eclipse.update.internal.core.Messages;
 import org.eclipse.update.internal.core.UpdateCore;
 import org.eclipse.update.internal.core.UpdateManagerUtils;

 /**
  * Root model object. Extended by all model objects.
  * <p>
  * This class cannot be instantiated and must be subclassed.
  * </p>
  * <p>
  * <b>Note:</b> This class/interface is part of an interim API that is still under development and expected to
  * change significantly before reaching stability. It is being made available at this early stage to solicit feedback
  * from pioneering adopters on the understanding that any code that uses this API will almost certainly be broken
  * (repeatedly) as the API evolves.
  * </p>
  * @deprecated The org.eclipse.update component has been replaced by Equinox p2.
  * This API will be deleted in a future release. See bug 311590 for details.
  */
 public abstract class ModelObject extends PlatformObject {

 	private boolean readOnly = false;

 	private static final String KEY_PREFIX = "%"; //$NON-NLS-1$
 	private static final String KEY_DOUBLE_PREFIX = KEY_PREFIX + KEY_PREFIX;

 	private static Map bundles;

 	/**
 	 * Creates a base model object.
 	 *
 	 * @since 2.0
 	 */
 	protected ModelObject() {
 	}

 	/**
 	 * Checks that this model object is writeable.  A runtime exception
 	 * is thrown if it is not.
 	 *
 	 * @since 2.0
 	 */
 	protected final void assertIsWriteable() {
 		Assert.isTrue(!isReadOnly(), Messages.ModelObject_ModelReadOnly);
 	}

 	/**
 	 * Sets this model object and all of its descendents to be read-only.
 	 * Subclasses may extend this implementation.
 	 *
 	 * @see #isReadOnly
 	 * @since 2.0
 	 */
 	public void markReadOnly() {
 		readOnly = true;
 	}

 	/**
 	 * Returns whether or not this model object is read-only.
 	 *
 	 * @return <code>true</code> if this model object is read-only,
 	 *		<code>false</code> otherwise
 	 * @see #markReadOnly
 	 * @since 2.0
 	 */
 	public boolean isReadOnly() {
 		return readOnly;
 	}

 	/**
 	 * Delegate setting of read-only
 	 *
 	 * @param o object to delegate to. Must be of type ModelObject.
 	 * @see #isReadOnly
 	 * @since 2.0
 	 */
 	protected void markReferenceReadOnly(ModelObject o) {
 		if (o == null)
 			return;
 		o.markReadOnly();
 	}

 	/**
 	 * Delegate setting of read-only
 	 *
 	 * @param o object array to delegate to. Each element must be of type ModelObject.
 	 * @see #isReadOnly
 	 * @since 2.0
 	 */
 	protected void markListReferenceReadOnly(ModelObject[] o) {
 		if (o == null)
 			return;
 		for (int i = 0; i < o.length; i++) {
 			o[i].markReadOnly();
 		}
 	}

 	/**
 	 * Resolve the model element. This method allows any relative URL strings
 	 * to be resolved to actual URL. It also allows any translatable strings
 	 * to be localized.
 	 *
 	 * Subclasses need to override this method to perform the actual resolution.
 	 * @param base base URL.
 	 * @param bundleURL resource bundle URL.
 	 * @exception MalformedURLException
 	 * @since 2.0
 	 */
 	public void resolve(URL base, URL bundleURL) throws MalformedURLException {
 		return;
 	}

 	/**
 	 * Delegate resolution to referenced model
 	 *
 	 * @param o object to delegate to. Must be of type ModelObject.
 	 * @param url base URL.
 	 * @param bundleURL resource bundle URL.
 	 * @exception MalformedURLException
 	 * @since 2.0
 	 */
 	protected void resolveReference(ModelObject o, URL url, URL bundleURL) throws MalformedURLException {
 		if (o == null)
 			return;
 		o.resolve(url, bundleURL);
 	}

 	/**
 	 * Delegate resolution to list of referenced models
 	 *
 	 * @param o object array to delegate to. Each element must be of type ModelObject.
 	 * @param url base URL.
 	 * @param bundleURL resource bundle URL.
 	 * @exception MalformedURLException
 	 * @since 2.0
 	 */
 	protected void resolveListReference(ModelObject[] o, URL url, URL bundleURL) throws MalformedURLException {
 		if (o == null)
 			return;
 		for (int i = 0; i < o.length; i++) {
 			o[i].resolve(url, bundleURL);
 		}
 	}

 	/**
 	 * Resolve a URL based on context
 	 *
 	 * @param context base URL.
 	 * @param bundleURL resource bundle URL.
 	 * @param urlString url string from model.
 	 * @return URL, or <code>null</code>.
 	 * @exception MalformedURLException
 	 * @since 2.0
 	 */
 	protected URL resolveURL(URL context, URL bundleURL, String urlString) throws MalformedURLException {

 		// URL string was not specified
 		if (urlString == null || urlString.trim().equals("")) //$NON-NLS-1$
 			return null;

 		// check to see if we have NL-sensitive URL
 		String resolvedUrlString = resolveNLString(bundleURL, urlString);

 		resolvedUrlString = resolvePlatfromConfiguration(resolvedUrlString);

 		// if we don't have a base url, use only the supplied string
 		if (context == null)
 			return new URL(resolvedUrlString);

 		// otherwise return new URL in context of base URL
 		return new URL(context, resolvedUrlString);
 	}
 	/**
 	 * Resolves the URL based on platfrom Configuration
 	 * $os$\$ws$\license.txt will become
 	 * win32\win32\license.txt on a system where os=win32 and ws=win32
 	 *
 	 * @param resolvedUrlString
 	 * @return String
 	 */
 	private String resolvePlatfromConfiguration(String resolvedUrlString) {
 		int osIndex = resolvedUrlString.indexOf("$os$"); //$NON-NLS-1$
 		if (osIndex != -1)
 			return getExtendedString(resolvedUrlString);

 		int wsIndex = resolvedUrlString.indexOf("$ws$"); //$NON-NLS-1$
 		if (wsIndex != -1)
 			return getExtendedString(resolvedUrlString);

 		int nlIndex = resolvedUrlString.indexOf("$nl$"); //$NON-NLS-1$
 		if (nlIndex != -1)
 			return getExtendedString(resolvedUrlString);

 		int archIndex = resolvedUrlString.indexOf("$arch$"); //$NON-NLS-1$
 		if (archIndex != -1)
 			return getExtendedString(resolvedUrlString);

 		return resolvedUrlString;
 	}

 	private String getExtendedString(String resolvedUrlString) {
 		IPath path = new Path(resolvedUrlString);
 		path = getExpandedPath(path);
 		if (UpdateCore.DEBUG && UpdateCore.DEBUG_SHOW_WARNINGS) {
 			UpdateCore.warn("Resolved :" + resolvedUrlString + " as:" + path.toOSString()); //$NON-NLS-1$ //$NON-NLS-2$
 		}

 		return path.toOSString();
 	}

 	private IPath getExpandedPath(IPath path) {
 		String first = path.segment(0);
 		if (first != null) {
 			IPath rest = getExpandedPath(path.removeFirstSegments(1));
 			if (first.equals("$ws$")) { //$NON-NLS-1$
 				path = new Path(SiteManager.getWS()).append(rest);
 			} else if (first.equals("$os$")) { //$NON-NLS-1$
 				path = new Path(SiteManager.getOS()).append(rest);
 			} else if (first.equals("$nl$")) { //$NON-NLS-1$
 				path = new Path(SiteManager.getNL()).append(rest);
 			} else if (first.equals("$arch$")) { //$NON-NLS-1$
 				path = new Path(SiteManager.getOSArch()).append(rest);
 			}
 		}
 		return path;
 	}

 	/**
 	 * Returns a resource string corresponding to the given argument
 	 * value and bundle.
 	 * If the argument value specifies a resource key, the string
 	 * is looked up in the given resource bundle. If the argument does not
 	 * specify a valid key, the argument itself is returned as the
 	 * resource string. The key lookup is performed against the
 	 * specified resource bundle. If a resource string
 	 * corresponding to the key is not found in the resource bundle
 	 * the key value, or any default text following the key in the
 	 * argument value is returned as the resource string.
 	 * A key is identified as a string begining with the "%" character.
 	 * Note that the "%" character is stripped off prior to lookup
 	 * in the resource bundle.
 	 * <p>
 	 * For example, assume resource bundle plugin.properties contains
 	 * name = Project Name
 	 * <pre>
 	 *     resolveNLString(b,"Hello World") returns "Hello World"</li>
 	 *     resolveNLString(b,"%name") returns "Project Name"</li>
 	 *     resolveNLString(b,"%name Hello World") returns "Project Name"</li>
 	 *     resolveNLString(b,"%abcd Hello World") returns "Hello World"</li>
 	 *     resolveNLString(b,"%abcd") returns "%abcd"</li>
 	 *     resolveNLString(b,"%%name") returns "%name"</li>
 	 * </pre>
 	 * </p>
 	 *
 	 * @param bundleURL resource bundle url.
 	 * @param string translatable string from model
 	 * @return string, or <code>null</code>
 	 * @since 2.0
 	 */
 	protected String resolveNLString(URL bundleURL, String string) {

 		if (string == null)
 			return null;

 		String s = string.trim();

 		if (s.equals("")) //$NON-NLS-1$
 			return string;

 		if (!s.startsWith(KEY_PREFIX))
 			return string;

 		if (s.startsWith(KEY_DOUBLE_PREFIX))
 			return s.substring(1);

 		int ix = s.indexOf(" "); //$NON-NLS-1$
 		String key = ix == -1 ? s : s.substring(0, ix);
 		String dflt = ix == -1 ? s : s.substring(ix + 1);

 		ResourceBundle b = getResourceBundle(bundleURL);

 		if (b == null)
 			return dflt;

 		try {
 			return b.getString(key.substring(1));
 		} catch (MissingResourceException e) {
 			return dflt;
 		}
 	}

 	/**
 	 * Returns a concrete array type for the elements of the specified
 	 * list. The method assumes all the elements of the list are the same
 	 * concrete type as the first element in the list.
 	 *
 	 * @param l list
 	 * @return concrete array type, or <code>null</code> if the array type
 	 * could not be determined (the list is <code>null</code> or empty)
 	 * @since 2.0
 	 */
 	protected Object[] arrayTypeFor(List l) {
 		if (l == null || l.size() == 0)
 			return null;
 		return (Object[]) Array.newInstance(l.get(0).getClass(), 0);
 	}

 	/**
 	 * Returns a concrete array type for the elements of the specified
 	 * set. The method assumes all the elements of the set are the same
 	 * concrete type as the first element in the set.
 	 *
 	 * @param s set
 	 * @return concrete array type, or <code>null</code> if the array type
 	 * could not be determined (the set is <code>null</code> or empty)
 	 * @since 2.0
 	 */
 	protected Object[] arrayTypeFor(Set s) {
 		if (s == null || s.size() == 0)
 			return null;
 		Iterator i = s.iterator();
 		return (Object[]) Array.newInstance(i.next().getClass(), 0);
 	}

 	/**
 		* Helper method to access resouce bundle for feature. The default
 		* implementation attempts to load the appropriately localized
 		* feature.properties file.
 		*
 		* @param url base URL used to load the resource bundle.
 		* @return resource bundle, or <code>null</code>.
 		* @since 2.0
 		*/
 	protected ResourceBundle getResourceBundle(URL url) {

 		if (url == null)
 			return null;

 		if (bundles == null) {
 			bundles = new HashMap();
 		} else {
 			ResourceBundle bundle = (ResourceBundle) bundles.get(url.toExternalForm());
 			if (bundle != null)
 				return bundle;
 		}

 		ResourceBundle bundle = null;
 		try {
 			url = UpdateManagerUtils.asDirectoryURL(url);
 			ClassLoader l = new URLClassLoader(new URL[] { url }, null);
 			bundle = ResourceBundle.getBundle(getPropertyName(), Locale.getDefault(), l);
 			bundles.put(url.toExternalForm(), bundle);
 		} catch (MissingResourceException e) {
 			UpdateCore.warn(e.getLocalizedMessage() + ":" + url.toExternalForm()); //$NON-NLS-1$
 		} catch (MalformedURLException e) {
 			UpdateCore.warn(e.getLocalizedMessage());
 		}
 		return bundle;
 	}

 	/**
 	 * Method getPropertyName.
 	 * @return String
 	 */
 	protected String getPropertyName() {
 		return Feature.FEATURE_FILE;
 	}

 }
	/*******************************************************************************
	* Copyright (c) 2000, 2010 IBM Corporation and others.
	* 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:
	* IBM Corporation - initial API and implementation
	*******************************************************************************/
	package org.eclipse.update.core.model;

	import java.lang.reflect.Array;
	import java.net.MalformedURLException;
	import java.net.URL;
	import java.net.URLClassLoader;
	import java.util.HashMap;
	import java.util.Iterator;
	import java.util.List;
	import java.util.Locale;
	import java.util.Map;
	import java.util.MissingResourceException;
	import java.util.ResourceBundle;
	import java.util.Set;

	import org.eclipse.core.runtime.Assert;
	import org.eclipse.core.runtime.IPath;
	import org.eclipse.core.runtime.Path;
	import org.eclipse.core.runtime.PlatformObject;
	import org.eclipse.update.core.Feature;
	import org.eclipse.update.core.SiteManager;
	import org.eclipse.update.internal.core.Messages;
	import org.eclipse.update.internal.core.UpdateCore;
	import org.eclipse.update.internal.core.UpdateManagerUtils;

	/**
	* Root model object. Extended by all model objects.
	* <p>
	* This class cannot be instantiated and must be subclassed.
	* </p>
	* <p>
	* <b>Note:</b> This class/interface is part of an interim API that is still under development and expected to
	* change significantly before reaching stability. It is being made available at this early stage to solicit feedback
	* from pioneering adopters on the understanding that any code that uses this API will almost certainly be broken
	* (repeatedly) as the API evolves.
	* </p>
	* @deprecated The org.eclipse.update component has been replaced by Equinox p2.
	* This API will be deleted in a future release. See bug 311590 for details.
	*/
	public abstract class ModelObject extends PlatformObject {

	private boolean readOnly = false;

	private static final String KEY_PREFIX = "%"; //$NON-NLS-1$
	private static final String KEY_DOUBLE_PREFIX = KEY_PREFIX + KEY_PREFIX;

	private static Map bundles;

	/**
	* Creates a base model object.
	*
	* @since 2.0
	*/
	protected ModelObject() {
	}

	/**
	* Checks that this model object is writeable. A runtime exception
	* is thrown if it is not.
	*
	* @since 2.0
	*/
	protected final void assertIsWriteable() {
	Assert.isTrue(!isReadOnly(), Messages.ModelObject_ModelReadOnly);
	}

	/**
	* Sets this model object and all of its descendents to be read-only.
	* Subclasses may extend this implementation.
	*
	* @see #isReadOnly
	* @since 2.0
	*/
	public void markReadOnly() {
	readOnly = true;
	}

	/**
	* Returns whether or not this model object is read-only.
	*
	* @return <code>true</code> if this model object is read-only,
	* <code>false</code> otherwise
	* @see #markReadOnly
	* @since 2.0
	*/
	public boolean isReadOnly() {
	return readOnly;
	}

	/**
	* Delegate setting of read-only
	*
	* @param o object to delegate to. Must be of type ModelObject.
	* @see #isReadOnly
	* @since 2.0
	*/
	protected void markReferenceReadOnly(ModelObject o) {
	if (o == null)
	return;
	o.markReadOnly();
	}

	/**
	* Delegate setting of read-only
	*
	* @param o object array to delegate to. Each element must be of type ModelObject.
	* @see #isReadOnly
	* @since 2.0
	*/
	protected void markListReferenceReadOnly(ModelObject[] o) {
	if (o == null)
	return;
	for (int i = 0; i < o.length; i++) {
	o[i].markReadOnly();
	}
	}

	/**
	* Resolve the model element. This method allows any relative URL strings
	* to be resolved to actual URL. It also allows any translatable strings
	* to be localized.
	*
	* Subclasses need to override this method to perform the actual resolution.
	* @param base base URL.
	* @param bundleURL resource bundle URL.
	* @exception MalformedURLException
	* @since 2.0
	*/
	public void resolve(URL base, URL bundleURL) throws MalformedURLException {
	return;
	}

	/**
	* Delegate resolution to referenced model
	*
	* @param o object to delegate to. Must be of type ModelObject.
	* @param url base URL.
	* @param bundleURL resource bundle URL.
	* @exception MalformedURLException
	* @since 2.0
	*/
	protected void resolveReference(ModelObject o, URL url, URL bundleURL) throws MalformedURLException {
	if (o == null)
	return;
	o.resolve(url, bundleURL);
	}

	/**
	* Delegate resolution to list of referenced models
	*
	* @param o object array to delegate to. Each element must be of type ModelObject.
	* @param url base URL.
	* @param bundleURL resource bundle URL.
	* @exception MalformedURLException
	* @since 2.0
	*/
	protected void resolveListReference(ModelObject[] o, URL url, URL bundleURL) throws MalformedURLException {
	if (o == null)
	return;
	for (int i = 0; i < o.length; i++) {
	o[i].resolve(url, bundleURL);
	}
	}

	/**
	* Resolve a URL based on context
	*
	* @param context base URL.
	* @param bundleURL resource bundle URL.
	* @param urlString url string from model.
	* @return URL, or <code>null</code>.
	* @exception MalformedURLException
	* @since 2.0
	*/
	protected URL resolveURL(URL context, URL bundleURL, String urlString) throws MalformedURLException {

	// URL string was not specified
	if (urlString == null \|\| urlString.trim().equals("")) //$NON-NLS-1$
	return null;

	// check to see if we have NL-sensitive URL
	String resolvedUrlString = resolveNLString(bundleURL, urlString);

	resolvedUrlString = resolvePlatfromConfiguration(resolvedUrlString);

	// if we don't have a base url, use only the supplied string
	if (context == null)
	return new URL(resolvedUrlString);

	// otherwise return new URL in context of base URL
	return new URL(context, resolvedUrlString);
	}
	/**
	* Resolves the URL based on platfrom Configuration
	* $os$\$ws$\license.txt will become
	* win32\win32\license.txt on a system where os=win32 and ws=win32
	*
	* @param resolvedUrlString
	* @return String
	*/
	private String resolvePlatfromConfiguration(String resolvedUrlString) {
	int osIndex = resolvedUrlString.indexOf("$os$"); //$NON-NLS-1$
	if (osIndex != -1)
	return getExtendedString(resolvedUrlString);

	int wsIndex = resolvedUrlString.indexOf("$ws$"); //$NON-NLS-1$
	if (wsIndex != -1)
	return getExtendedString(resolvedUrlString);

	int nlIndex = resolvedUrlString.indexOf("$nl$"); //$NON-NLS-1$
	if (nlIndex != -1)
	return getExtendedString(resolvedUrlString);

	int archIndex = resolvedUrlString.indexOf("$arch$"); //$NON-NLS-1$
	if (archIndex != -1)
	return getExtendedString(resolvedUrlString);

	return resolvedUrlString;
	}

	private String getExtendedString(String resolvedUrlString) {
	IPath path = new Path(resolvedUrlString);
	path = getExpandedPath(path);
	if (UpdateCore.DEBUG && UpdateCore.DEBUG_SHOW_WARNINGS) {
	UpdateCore.warn("Resolved :" + resolvedUrlString + " as:" + path.toOSString()); //$NON-NLS-1$ //$NON-NLS-2$
	}

	return path.toOSString();
	}

	private IPath getExpandedPath(IPath path) {
	String first = path.segment(0);
	if (first != null) {
	IPath rest = getExpandedPath(path.removeFirstSegments(1));
	if (first.equals("$ws$")) { //$NON-NLS-1$
	path = new Path(SiteManager.getWS()).append(rest);
	} else if (first.equals("$os$")) { //$NON-NLS-1$
	path = new Path(SiteManager.getOS()).append(rest);
	} else if (first.equals("$nl$")) { //$NON-NLS-1$
	path = new Path(SiteManager.getNL()).append(rest);
	} else if (first.equals("$arch$")) { //$NON-NLS-1$
	path = new Path(SiteManager.getOSArch()).append(rest);
	}
	}
	return path;
	}

	/**
	* Returns a resource string corresponding to the given argument
	* value and bundle.
	* If the argument value specifies a resource key, the string
	* is looked up in the given resource bundle. If the argument does not
	* specify a valid key, the argument itself is returned as the
	* resource string. The key lookup is performed against the
	* specified resource bundle. If a resource string
	* corresponding to the key is not found in the resource bundle
	* the key value, or any default text following the key in the
	* argument value is returned as the resource string.
	* A key is identified as a string begining with the "%" character.
	* Note that the "%" character is stripped off prior to lookup
	* in the resource bundle.
	* <p>
	* For example, assume resource bundle plugin.properties contains
	* name = Project Name
	* <pre>
	* resolveNLString(b,"Hello World") returns "Hello World"</li>
	* resolveNLString(b,"%name") returns "Project Name"</li>
	* resolveNLString(b,"%name Hello World") returns "Project Name"</li>
	* resolveNLString(b,"%abcd Hello World") returns "Hello World"</li>
	* resolveNLString(b,"%abcd") returns "%abcd"</li>
	* resolveNLString(b,"%%name") returns "%name"</li>
	* </pre>
	* </p>
	*
	* @param bundleURL resource bundle url.
	* @param string translatable string from model
	* @return string, or <code>null</code>
	* @since 2.0
	*/
	protected String resolveNLString(URL bundleURL, String string) {

	if (string == null)
	return null;

	String s = string.trim();

	if (s.equals("")) //$NON-NLS-1$
	return string;

	if (!s.startsWith(KEY_PREFIX))
	return string;

	if (s.startsWith(KEY_DOUBLE_PREFIX))
	return s.substring(1);

	int ix = s.indexOf(" "); //$NON-NLS-1$
	String key = ix == -1 ? s : s.substring(0, ix);
	String dflt = ix == -1 ? s : s.substring(ix + 1);

	ResourceBundle b = getResourceBundle(bundleURL);

	if (b == null)
	return dflt;

	try {
	return b.getString(key.substring(1));
	} catch (MissingResourceException e) {
	return dflt;
	}
	}

	/**
	* Returns a concrete array type for the elements of the specified
	* list. The method assumes all the elements of the list are the same
	* concrete type as the first element in the list.
	*
	* @param l list
	* @return concrete array type, or <code>null</code> if the array type
	* could not be determined (the list is <code>null</code> or empty)
	* @since 2.0
	*/
	protected Object[] arrayTypeFor(List l) {
	if (l == null \|\| l.size() == 0)
	return null;
	return (Object[]) Array.newInstance(l.get(0).getClass(), 0);
	}

	/**
	* Returns a concrete array type for the elements of the specified
	* set. The method assumes all the elements of the set are the same
	* concrete type as the first element in the set.
	*
	* @param s set
	* @return concrete array type, or <code>null</code> if the array type
	* could not be determined (the set is <code>null</code> or empty)
	* @since 2.0
	*/
	protected Object[] arrayTypeFor(Set s) {
	if (s == null \|\| s.size() == 0)
	return null;
	Iterator i = s.iterator();
	return (Object[]) Array.newInstance(i.next().getClass(), 0);
	}

	/**
	* Helper method to access resouce bundle for feature. The default
	* implementation attempts to load the appropriately localized
	* feature.properties file.
	*
	* @param url base URL used to load the resource bundle.
	* @return resource bundle, or <code>null</code>.
	* @since 2.0
	*/
	protected ResourceBundle getResourceBundle(URL url) {

	if (url == null)
	return null;

	if (bundles == null) {
	bundles = new HashMap();
	} else {
	ResourceBundle bundle = (ResourceBundle) bundles.get(url.toExternalForm());
	if (bundle != null)
	return bundle;
	}

	ResourceBundle bundle = null;
	try {
	url = UpdateManagerUtils.asDirectoryURL(url);
	ClassLoader l = new URLClassLoader(new URL[] { url }, null);
	bundle = ResourceBundle.getBundle(getPropertyName(), Locale.getDefault(), l);
	bundles.put(url.toExternalForm(), bundle);
	} catch (MissingResourceException e) {
	UpdateCore.warn(e.getLocalizedMessage() + ":" + url.toExternalForm()); //$NON-NLS-1$
	} catch (MalformedURLException e) {
	UpdateCore.warn(e.getLocalizedMessage());
	}
	return bundle;
	}

	/**
	* Method getPropertyName.
	* @return String
	*/
	protected String getPropertyName() {
	return Feature.FEATURE_FILE;
	}

	}