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Glassfish example source code file (CommonClassLoaderServiceImpl.java)

This example Glassfish source code file (CommonClassLoaderServiceImpl.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

apiclassloader, apiclassloader, arraylist, classloader, commonclassloaderserviceimpl, file, file, io, jarfilefilter, jarfilefilter, list, log, logging, net, network, noi18n, object, string, string, util

The Glassfish CommonClassLoaderServiceImpl.java source code

/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 2007-2010 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:
 * "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 com.sun.enterprise.v3.server;

import com.sun.logging.LogDomains;
import com.sun.enterprise.util.SystemPropertyConstants;
import org.jvnet.hk2.annotations.Inject;
import org.jvnet.hk2.annotations.Service;
import org.jvnet.hk2.component.PostConstruct;
import org.glassfish.api.admin.ServerEnvironment;

import java.io.File;
import java.io.FilenameFilter;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.jar.JarFile;
import java.util.jar.Manifest;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * This class is responsible for setting up Common Class Loader. As the
 * name suggests, Common Class Loader is common to all deployed applications.
 * Common Class Loader is responsible for loading classes from
 * following URLs (the order is strictly maintained):
 * lib/*.jar:domain_dir/lib/classes:domain_dir/lib/*.jar:DERBY_DRIVERS.
 * Please note that domain_dir/lib/classes comes before domain_dir/lib/*.jar,
 * just like WEB-INF/classes is searched first before WEB-INF/lib/*.jar.
 * DERBY_DRIVERS are added to this class loader, because GlassFish ships with Derby database by default
 * and it makes them available to users by default. Earlier, they used to be available to applications via
 * launcher classloader, but now they are available via this class loader (see issue 13612 for more details on this). 
 *
 * It applies a special rule while handling jars in install_root/lib.
 * In order to maintain file layout compatibility (see  issue #9526),
 * we add jars like javaee.jar and appserv-rt.jar which need to be excluded
 * from runtime classloaders in the server side, as they are already available via
 * PublicAPIClassLoader. So, before we add any jar from install_root/lib,
 * we look at their manifest entry and skip the ones that have an entry
 * GlassFish-ServerExcluded: true
 *
 * @author Sanjeeb.Sahoo@Sun.COM
 */
@Service
public class CommonClassLoaderServiceImpl implements PostConstruct {
    /**
     * The common classloader.
     */
    private ClassLoader commonClassLoader;

    @Inject
    APIClassLoaderServiceImpl acls;

    @Inject
    ServerEnvironment env;

    final static Logger logger = LogDomains.getLogger(CommonClassLoaderServiceImpl.class, LogDomains.LOADER_LOGGER);
    private ClassLoader APIClassLoader;
    private String commonClassPath = "";

    private static final String SERVER_EXCLUDED_ATTR_NAME = "GlassFish-ServerExcluded";

    public void postConstruct() {
        APIClassLoader = acls.getAPIClassLoader();
        assert (APIClassLoader != null);
        createCommonClassLoader();
    }

    private void createCommonClassLoader() {
        List<File> cpElements = new ArrayList();
        File domainDir = env.getDomainRoot();
        // I am forced to use System.getProperty, as there is no API that makes
        // the installRoot available. Sad, but true. Check dev forum on this.
        final String installRoot = System.getProperty(
                SystemPropertyConstants.INSTALL_ROOT_PROPERTY);

        // See https://glassfish.dev.java.net/issues/show_bug.cgi?id=5872
        // In case of embedded GF, we may not have an installRoot.
        if (installRoot!=null) {
            File installDir = new File(installRoot);
            File installLibPath = new File(installDir, "lib");
            if (installLibPath.isDirectory()) {
                Collections.addAll(cpElements,
                        installLibPath.listFiles(new CompiletimeJarFileFilter()));
            }
        } else {
            logger.logp(Level.WARNING, "CommonClassLoaderServiceImpl",
                    "createCommonClassLoader",
                    "System property called {0} is null, is this intended?",
                    new Object[]{SystemPropertyConstants.INSTALL_ROOT_PROPERTY});
        }
        File domainClassesDir = new File(domainDir, "lib/classes/"); // NOI18N
        if (domainClassesDir.exists()) {
            cpElements.add(domainClassesDir);
        }
        final File domainLib = new File(domainDir, "lib/"); // NOI18N
        if (domainLib.isDirectory()) {
            Collections.addAll(cpElements,
                    domainLib.listFiles(new JarFileFilter()));
        }
        // See issue https://glassfish.dev.java.net/issues/show_bug.cgi?id=13612
        // We no longer add derby jars to launcher class loader, we add them to common class loader instead.
        cpElements.addAll(findDerbyClient());
        List<URL> urls = new ArrayList();
        StringBuilder cp = new StringBuilder();
        for (File f : cpElements) {
            try {
                urls.add(f.toURI().toURL());
                if (cp.length() > 0) {
                    cp.append(File.pathSeparator);
                }
                cp.append(f.getAbsolutePath());
            } catch (MalformedURLException e) {
                logger.logp(Level.WARNING, "ClassLoaderManager",
                        "postConstruct", "e = {0}", new Object[]{e});
            }
        }
        commonClassPath = cp.toString();
        if (!urls.isEmpty()) {
            // Skip creation of an unnecessary classloader in the hierarchy,
            // when all it would have done was to delegate up.
            commonClassLoader = new URLClassLoader(
                    urls.toArray(new URL[urls.size()]), APIClassLoader);
        } else {
            logger.logp(Level.FINE, "CommonClassLoaderManager",
                    "Skipping creation of CommonClassLoader " +
                            "as there are no libraries available",
                    "urls = {0}", new Object[]{urls});
        }
    }

    public ClassLoader getCommonClassLoader() {
        return commonClassLoader != null ? commonClassLoader : APIClassLoader;
    }

    public String getCommonClassPath() {
        return commonClassPath;
    }

    private List<File> findDerbyClient() {
        final String DERBY_HOME_PROP = "AS_DERBY_INSTALL";
        String derbyHome = env.getStartupContext().getArguments().getProperty(DERBY_HOME_PROP,
                System.getProperty(DERBY_HOME_PROP));
        File derbyLib = null;
        if (derbyHome != null) {
            derbyLib = new File(derbyHome, "lib");
        }
        if (derbyLib == null || !derbyLib.exists()) {
            // maybe the jdk...
            if (System.getProperty("java.version").compareTo("1.6") > 0) {
                File jdkHome = new File(System.getProperty("java.home"));
                derbyLib = new File(jdkHome, "../db/lib");
            }
        }
        if (!derbyLib.exists()) {
            logger.info("Cannot find javadb client jar file, derby jdbc driver will not be available by default.");
            return Collections.EMPTY_LIST;
        }

        return Arrays.asList(derbyLib.listFiles(new FilenameFilter(){
            public boolean accept(File dir, String name) {
                // Include only files having .jar extn and exclude all localisation jars, because they are
                // already mentioned in the Class-Path header of the main jars
                return (name.endsWith(".jar") && !name.startsWith("derbyLocale_"));
            }
        }));
    }

    private static class JarFileFilter implements FilenameFilter {
        private final String JAR_EXT = ".jar"; // NOI18N

        public boolean accept(File dir, String name) {
            return name.endsWith(JAR_EXT);
        }
    }

    private static class CompiletimeJarFileFilter extends JarFileFilter {
        /*
         * See https://glassfish.dev.java.net/issues/show_bug.cgi?id=9526
         */
        @Override
        public boolean accept(File dir, String name)
        {
            if (super.accept(dir, name)) {
                File file = new File(dir, name);
                JarFile jar = null;
                try
                {
                    jar = new JarFile(file);
                    Manifest manifest = jar.getManifest();
                    if (manifest != null) {
                        String exclude = manifest.getMainAttributes().
                                getValue(SERVER_EXCLUDED_ATTR_NAME);
                        if (exclude != null && exclude.equalsIgnoreCase("true")) {
                            return false;
                        }
                    }
                }
                catch (IOException e)
                {
                    logger.log(Level.WARNING, "CommonClassLoaderServiceImpl " +
                            "is unable to process " + file.getAbsolutePath() +
                            " because of exception.", e);
                } finally {
                    try
                    {
                        if (jar != null) jar.close();
                    }
                    catch (IOException e)
                    {
                        // ignore
                    }
                }
                return true;
            }
            return false;
        }
    }
}

Other Glassfish examples (source code examples)

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