Glassfish example source code file (ClassLoaderHierarchyImpl.java)

This example Glassfish source code file (ClassLoaderHierarchyImpl.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, classloader, file, inject, inject, io, list, log, logging, malformedurlexception, net, network, resolveerror, string, string, systemvariableresolver, systemvariableresolver, tokenizer, translationexception, util

The Glassfish ClassLoaderHierarchyImpl.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:
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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
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 * 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 org.glassfish.internal.api.ClassLoaderHierarchy;
import org.jvnet.hk2.annotations.Inject;
import org.jvnet.hk2.annotations.Service;
import org.jvnet.hk2.component.Habitat;
import org.jvnet.hk2.component.Inhabitant;
import org.jvnet.hk2.component.PostConstruct;
import org.jvnet.hk2.config.TranslationException;
import org.jvnet.hk2.config.VariableResolver;
import org.glassfish.internal.api.DelegatingClassLoader;
import org.glassfish.internal.api.ConnectorClassLoaderService;
import org.glassfish.api.deployment.archive.ReadableArchive;
import org.glassfish.api.deployment.DeploymentContext;

import java.net.URI;
import java.net.MalformedURLException;
import java.util.List;
import java.util.ArrayList;
import java.util.Collection;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.jar.Manifest;
import java.io.File;
import java.io.IOException;

import com.sun.enterprise.module.*;
import com.sun.enterprise.module.ModuleDefinition;
import com.sun.enterprise.module.Repository;
import com.sun.enterprise.module.ResolveError;
import com.sun.enterprise.module.ManifestConstants;
import com.sun.enterprise.module.common_impl.DirectoryBasedRepository;
import com.sun.enterprise.module.common_impl.Tokenizer;


/**
 * @author Sanjeeb.Sahoo@Sun.COM
 */
@Service
public class ClassLoaderHierarchyImpl implements ClassLoaderHierarchy {
    @Inject APIClassLoaderServiceImpl apiCLS;

    @Inject CommonClassLoaderServiceImpl commonCLS;

    //For distributions where connector module is not available.
    @Inject(optional = true) ConnectorClassLoaderService connectorCLS;

    @Inject
    AppLibClassLoaderServiceImpl applibCLS;

    @Inject
    ModulesRegistry modulesRegistry;

    @Inject
    Logger logger;

    @Inject
    Habitat habitat;

    SystemVariableResolver resolver = new SystemVariableResolver();

    public ClassLoader getAPIClassLoader() {
        return apiCLS.getAPIClassLoader();
    }

    public ClassLoader getCommonClassLoader() {
        return commonCLS.getCommonClassLoader();
    }

    public String getCommonClassPath() {
        return commonCLS.getCommonClassPath();
    }

    public DelegatingClassLoader getConnectorClassLoader(String application) {
        // For distributions where connector module (connector CL) is not available, use empty classloader with parent
        if(connectorCLS != null){
            return connectorCLS.getConnectorClassLoader(application);
        }else{
            return new DelegatingClassLoader(commonCLS.getCommonClassLoader());
        }
    }

    public ClassLoader getAppLibClassLoader(String application, List<URI> libURIs) throws MalformedURLException {
        return applibCLS.getAppLibClassLoader(application, libURIs);
    }

    public DelegatingClassLoader.ClassFinder getAppLibClassFinder(List<URI> libURIs) throws MalformedURLException {
        return applibCLS.getAppLibClassFinder(libURIs);
    }

    /**
     * Sets up the parent class loader for the application class loader.
     * Application class loader are under the control of the ArchiveHandler since
     * a special archive file format will require a specific class loader.
     *
     * However GlassFish needs to be able to add capabilities to the application
     * like adding APIs accessibility, this is done through its parent class loader
     * which we create and maintain.
     *
     * @param parent the parent class loader
     * @param context deployment context
     * @return class loader capable of loading public APIs identified by the deployers
     * @throws ResolveError if one of the deployer's public API module is not found.
     */
    public ClassLoader createApplicationParentCL(ClassLoader parent, DeploymentContext context)
        throws ResolveError {

        final ReadableArchive source = context.getSource();
        List<ModuleDefinition> defs = new ArrayList();

        // now let's see if the application is requesting any module imports
        Manifest m=null;
        try {
            m = source.getManifest();
        } catch (IOException e) {
            logger.log(Level.SEVERE, "Cannot load application's manifest file :", e.getMessage());
            if (logger.isLoggable(Level.FINE)) {
                logger.log(Level.FINE, e.getMessage(), e);
            }
        }
        if (m!=null) {
            String importedBundles = m.getMainAttributes().getValue(ManifestConstants.BUNDLE_IMPORT_NAME);
            if (importedBundles!=null) {
                for( String token : new Tokenizer(importedBundles,",")) {
                    Collection<Module> modules = modulesRegistry.getModules(token);
                    if (modules.size() ==1) {
                        defs.add(modules.iterator().next().getModuleDefinition());
                    } else {
                        throw new ResolveError("Not able to locate a unique module by name " + token);
                    }
                }
            }

	    // Applications can add an additional osgi repos...
            String additionalRepo = m.getMainAttributes().getValue(org.glassfish.api.ManifestConstants.GLASSFISH_REQUIRE_REPOSITORY);
	    if (additionalRepo != null) {
                for (String token : new Tokenizer(additionalRepo, ",")) {
		    // Each entry should be name=path
		    int equals = token.indexOf('=');
		    if (equals == -1) {
			// Missing '='...
			throw new IllegalArgumentException("\""
			    + org.glassfish.api.ManifestConstants.GLASSFISH_REQUIRE_REPOSITORY
			    + ": " + additionalRepo + "\" is missing an '='.  "
			    + "It must be in the format: name=path[,name=path]...");
		    }
		    String name = token.substring(0, equals);
		    String path = token.substring(++equals);
		    addRepository(name, resolver.translate(path));
		}
	    }

	    // Applications can also request to be wired to implementors of certain services.
	    // That means that any module implementing the requested service will be accessible
	    // by the parent class loader of the application.
            String requestedWiring = m.getMainAttributes().getValue(org.glassfish.api.ManifestConstants.GLASSFISH_REQUIRE_SERVICES);
            if (requestedWiring!=null) {
                for (String token : new Tokenizer(requestedWiring, ",")) {
                    for (Inhabitant<?> impl : habitat.getInhabitantsByContract(token)) {
                        Module wiredBundle = modulesRegistry.find(impl.get().getClass());
                        if (wiredBundle!=null) {
                            defs.add(wiredBundle.getModuleDefinition());
                        }
                    }
                }
            }
        }

        if (defs.isEmpty()) {
            return parent;
        }  else {
            return modulesRegistry.getModulesClassLoader(parent, defs);
        }
    }

    /**
     *	<p> This method installs the admin console OSGi bundle respository so
     *	    our plugins can be found.</p>
     */
    private void addRepository(String name, String path) {
	File pathFile = new File(path);
	Repository repo = new DirectoryBasedRepository(
		name, pathFile);
	modulesRegistry.addRepository(repo);
	try {
	    repo.initialize(); 
	} catch (IOException ex) {
	    logger.log(Level.SEVERE,
		"Problem initializing additional repository!", ex);
	}
    }

    /**
     *	<p> This class helps resolve ${} variables in Strings.

     */
    private static class SystemVariableResolver extends VariableResolver {
	SystemVariableResolver() {
	    super();
	}

	protected String getVariableValue(final String varName) throws TranslationException {
	    String result = null;

	    // first look for a system property
	    final Object value = System.getProperty(varName);
	    if (value != null) {
		result = "" + value;
	    } else {
		result = "${" + varName + "}";
	    }
	    return result;
	}

	/**
	    Return true if the string is a template string of the for ${...}
	 */
	public static boolean needsResolving(final String value) {
	    return (value != null) && (value.indexOf("${") != -1);
	}

	/**
	 *  Resolve the given String.
	 */
	public String resolve(final String value) throws TranslationException {
	    final String result = translate(value);
	    return result;
	}
    }
}