org.glassfish.appclient.client.JWSACCMaskingClassLoader Maven / Gradle / Ivy
/*
* Copyright (c) 2011, 2021 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package org.glassfish.appclient.client;
import java.util.Collection;
import java.util.Collections;
/**
* Masks classes or resources that are listed in the "endorsed" packages that GlassFish provides.
*
* During Java Web Start launches we cannot set java.endorsed.dirs to have the bootstrap class loader look in the
* GlassFish-provided JARs for classes and resources that would otherwise be found in the system JARs (rt.jar for
* example). We need some other way of making sure the GlassFish-provided JARs are used. Those JARs are listed in the
* JNLP documents for the app, so the JNLPClassLoader which Java Web Start provides will find them if we give it a
* chance.
*
* This loader knows what packages are in the GlassFish-provided endorsed JARs and will report any matching class or
* resource as not found. When an instance of this loader is inserted as the parent of the JNLPClassLoader then the
* JNLPClassLoader will delegate to it first. The masking loader will report GlassFish-provided content as not found, so
* the JNLPClassLoader will try to resolve them itself. That resolution will use the downloaded GlassFish JARs, thereby
* making sure the Java Web Start launch uses the GlassFish-provided endorsed JARs instead of whatever happens to be in
* the Java system JARs.
*
* @author Tim Quinn
*/
class JWSACCMaskingClassLoader extends MaskingClassLoader {
private final Collection endorsedPackagesToMask;
JWSACCMaskingClassLoader(ClassLoader parent, Collection endorsedPackagesToMask) {
super(parent, Collections.EMPTY_SET /* punchins */, Collections.EMPTY_SET /* multiples */,
false /* useExplicitCallsToFindSystemClass */);
this.endorsedPackagesToMask = endorsedPackagesToMask;
}
@Override
protected boolean isDottedNameLoadableByParent(final String name) {
/*
* Currently the only masked packages start with javax. or org. Check the prefix as an optimization to avoid searching
* the collection.
*/
if (!(name.startsWith("javax.") || name.startsWith("org."))) {
return true;
}
final String packageName = name.substring(0, name.lastIndexOf("."));
if (endorsedPackagesToMask.contains(packageName)) {
/*
* The requested name is one to be masked, so do not let the caller delegate to its parent.
*/
return false;
}
/*
* The requested name should not be masked. Allow the caller to delegate to its parent first.
*/
return true;
}
}