Glassfish example source code file (ClassPathManager16.java)

This example Glassfish source code file (ClassPathManager16.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Glassfish tags/keywords

classloader, classnotfoundexception, classpathmanager, classpathmanager16, classpathmanager16, file, file, illegalaccessexception, io, jar, jarfile, jarfile, net, network, reflection, runtimeexception, string, string, uri

The Glassfish ClassPathManager16.java source code

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 1997-2010 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:
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 * 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.jws.boot;

import java.io.File;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.jar.JarFile;

/**
 * Class Path manager for Java Web Start-aware ACC running under Java runtime 1.6.
 *
 * @author tjquinn
 */
public class ClassPathManager16 extends ClassPathManager {
    
    /** Class object for the JNLPClassLoader class */
    private Class jnlpClassLoaderClass;

    /** Method object for the getJarFile method on JNLPClassLoader - only in 1.6 and later */
    private Method getJarFileMethod;

    /**
     *Returns a new instance of the class path manager for use under Java 1.6
     *@param loader the Java Web Start-provided class loader
     */
    protected ClassPathManager16(ClassLoader loader, boolean keepJWSClassLoader) {
        super(loader, keepJWSClassLoader);
        try {
            prepareIntrospectionInfo();
        } catch (Throwable thr) {
            throw new RuntimeException(thr);
        }
    }

    /**
     *Prepares the reflection-related private variables for later use in 
     *locating classes in JARs.
     *@throws ClassNotFoundException if the JNLPClassLoader class cannot be found
     *@throws NoSuchMethodException if the getJarFile method cannot be found
     */
    private void prepareIntrospectionInfo() throws ClassNotFoundException, NoSuchMethodException {
        jnlpClassLoaderClass = getJNLPClassLoader().loadClass("com.sun.jnlp.JNLPClassLoader");
        getJarFileMethod = jnlpClassLoaderClass.getDeclaredMethod("getJarFile", URL.class);
        getJarFileMethod.setAccessible(true);
    }

    public ClassLoader getParentClassLoader() {
        return (keepJWSClassLoader() ? getJnlpClassLoader() : getJNLPClassLoader().getParent());
    }

    public File findContainingJar(URL resourceURL) throws IllegalArgumentException, URISyntaxException, MalformedURLException, IllegalAccessException, InvocationTargetException {
        File result = null;
        if (resourceURL != null) {
            /*
             *The URL will be similar to http://host:port/...path-in-server-namespace!resource-spec
             *Extract the part preceding the ! and ask the Java Web Start loader to
             *find the locally-cached JAR file corresponding to that part of the URL.
             */
            URI resourceURI = resourceURL.toURI();
            String ssp = resourceURI.getSchemeSpecificPart();
            String jarOnlySSP = ssp.substring(0, ssp.indexOf('!'));

            URL jarOnlyURL = new URL(jarOnlySSP).toURI().toURL();

            /*
             *Use introspection to invoke the method.  This avoids complications
             *in building the app server under Java 1.5 in which the JNLPClassLoader
             *does not provide the getJarFile method.
             */
            JarFile jarFile = (JarFile) getJarFileMethod.invoke(getJNLPClassLoader(), jarOnlyURL);
            if (jarFile == null) {
                throw new IllegalArgumentException(resourceURL.toExternalForm());
            }
            result = new File(jarFile.getName());
        }
        return result;
    }
}