org.glassfish.appclient.client.MaskingClassLoader Maven / Gradle / Ivy
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 2008-2011 Oracle and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* https://glassfish.dev.java.net/public/CDDL+GPL_1_1.html
* or packager/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at packager/legal/LICENSE.txt.
*
* GPL Classpath Exception:
* Oracle designates this particular file as subject to the "Classpath"
* exception as provided by Oracle in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
* "Portions Copyright [year] [name of copyright owner]"
*
* Contributor(s):
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*/
package org.glassfish.appclient.client;
import java.io.IOException;
import java.net.URL;
import java.util.*;
/**
* {@link ClassLoader} that masks a specified set of classes
* from its parent class loader.
*
*
* This code is used to create an isolated environment.
*
* @author Jerome Dochez
*/
public class MaskingClassLoader extends ClassLoader {
private final Set punchins = new HashSet();
private final String[] multiples;
private final boolean useExplicitCallsToFindSystemClass;
public MaskingClassLoader(ClassLoader parent, Collection punchins, Collection multiples) {
this(parent, punchins, multiples, true /* use explicit calls to findSystemClass*/);
}
/**
* Creates a new masking class loader letting a set of defined packages be loaded by the parent
* classloader. Multiples packages can be specified so that only the parent package needs to
* be provided.
*
* @param parent the parent classloader to delegate actual loading from when punchin is allowed
* @param punchins list of packages allowed to be visible from the parent
* @param multiples list of parent packages allowed to be visible from the parent class loader
*/
public MaskingClassLoader(ClassLoader parent, Collection punchins, Collection multiples,
boolean useExplicitCallsToFindSystemClass) {
super(parent);
this.punchins.addAll(punchins);
this.multiples = multiples.toArray(new String[multiples.size()]);
this.useExplicitCallsToFindSystemClass = useExplicitCallsToFindSystemClass;
}
@Override
protected synchronized Class loadClass(String name, boolean resolve) throws ClassNotFoundException {
// I do not mask java packages, and I only mask javax. stuff for now.
try {
if (useExplicitCallsToFindSystemClass) {
return findSystemClass(name);
}
} catch(ClassNotFoundException e) {
}
if (isDottedNameLoadableByParent(name)) {
return super.loadClass(name, resolve);
}
throw new ClassNotFoundException(name);
}
@Override
public URL getResource(String name) {
if (isDottedNameLoadableByParent(resourceToDotted(name))) {
return super.getResource(name);
} else {
return null;
}
}
@Override
public Enumeration getResources(String name) throws IOException {
if (isDottedNameLoadableByParent(resourceToDotted(name))) {
return super.getResources(name);
} else {
return new Enumeration() {
@Override
public boolean hasMoreElements() {
return false;
}
@Override
public URL nextElement() {
throw new NoSuchElementException();
}
};
}
}
private String resourceToDotted(String name) {
if (name.startsWith("/")) {
name = name.substring(1);
}
return name.replace("/", ".");
}
protected boolean isDottedNameLoadableByParent(final String name) {
if (!(name.startsWith("javax.") || name.startsWith("jakarta.") || name.startsWith("org."))) {
return true;
}
final String packageName = name.substring(0, name.lastIndexOf('.'));
if (punchins.contains(packageName)) {
return true;
}
for (String multiple : multiples) {
if (name.startsWith(multiple)) {
return true;
}
}
return false;
}
}