ResourceBundle: avoid a performance penalty by superfluous resource (and classes loaded by Class.forName) lookups on web server in applets.
/*
* JFreeChart : a free chart library for the Java(tm) platform
*
*
* (C) Copyright 2000-2008, by Object Refinery Limited and Contributors.
*
* Project Info: http://www.jfree.org/jfreechart/index.html
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
* License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
* --------------------------
* ResourceBundleWrapper.java
* --------------------------
* (C)opyright 2008, by Jess Thrysoee and Contributors.
*
* Original Author: Jess Thrysoee;
* Contributor(s): David Gilbert (for Object Refinery Limited);
*
* Changes
* -------
* 18-Dec-2008 : Version 1 (JT);
*
*/
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import java.util.ResourceBundle;
/**
* Wrapper of ResourceBundle.getBundle() methods. This wrapper is introduced to
* avoid a dramatic performance penalty by superfluous resource (and classes
* loaded by Class.forName) lookups on web server in applets.
*
* <pre>
* public class AppletC extends javax.swing.JApplet {
* public void init() {
* ResourceBundleWrapper.removeCodeBase(getCodeBase(),
* (URLClassLoader) getClass().getClassLoader());
* ...
* </pre>
*
* @see <a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4243379">
* Bug ID: 4243379</a>
* @see <a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4668479">
* Bug ID: 4668479</a>
*
* @since 1.0.12
*/
public class ResourceBundleWrapper {
/**
* A special class loader with no code base lookup. This field may be
* <code>null</code> (the field is only initialised if removeCodeBase() is
* called from an applet.
*/
private static URLClassLoader noCodeBaseClassLoader;
/**
* Private constructor.
*/
private ResourceBundleWrapper() {
// all methods are static, no need to instantiate
}
/**
* Instantiate a {@link URLClassLoader} for resource lookups where the
* codeBase URL is removed. This method is typically called from an
* applet's init() method. If this method is never called, the
* <code>getBundle()</code> methods map to the standard
* {@link ResourceBundle} lookup methods.
*
* @param codeBase the codeBase URL.
* @param urlClassLoader the class loader.
*/
public static void removeCodeBase(URL codeBase,
URLClassLoader urlClassLoader) {
List urlsNoBase = new ArrayList();
URL[] urls = urlClassLoader.getURLs();
for (int i = 0; i < urls.length; i++) {
if (! urls[i].sameFile(codeBase)) {
urlsNoBase.add(urls[i]);
}
}
// substitute the filtered URL list
URL[] urlsNoBaseArray = (URL[]) urlsNoBase.toArray(new URL[0]);
noCodeBaseClassLoader = URLClassLoader.newInstance(urlsNoBaseArray);
}
/**
* Finds and returns the specified resource bundle.
*
* @param baseName the base name.
*
* @return The resource bundle.
*/
public static final ResourceBundle getBundle(String baseName) {
// the noCodeBaseClassLoader is configured by a call to the
// removeCodeBase() method, typically in the init() method of an
// applet...
if (noCodeBaseClassLoader != null) {
return ResourceBundle.getBundle(baseName, Locale.getDefault(),
noCodeBaseClassLoader);
}
else {
// standard ResourceBundle behaviour
return ResourceBundle.getBundle(baseName);
}
}
/**
* Finds and returns the specified resource bundle.
*
* @param baseName the base name.
* @param locale the locale.
*
* @return The resource bundle.
*/
public static final ResourceBundle getBundle(String baseName,
Locale locale) {
// the noCodeBaseClassLoader is configured by a call to the
// removeCodeBase() method, typically in the init() method of an
// applet...
if (noCodeBaseClassLoader != null) {
return ResourceBundle.getBundle(baseName, locale,
noCodeBaseClassLoader);
}
else {
// standard ResourceBundle behaviour
return ResourceBundle.getBundle(baseName, locale);
}
}
/**
* Maps directly to <code>ResourceBundle.getBundle(baseName, locale,
* loader)</code>.
*
* @param baseName the base name.
* @param locale the locale.
* @param loader the class loader.
*
* @return The resource bundle.
*/
public static ResourceBundle getBundle(String baseName, Locale locale,
ClassLoader loader) {
return ResourceBundle.getBundle(baseName, locale, loader);
}
}
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