001    /*
002     * JBoss DNA (http://www.jboss.org/dna)
003     * See the COPYRIGHT.txt file distributed with this work for information
004     * regarding copyright ownership.  Some portions may be licensed
005     * to Red Hat, Inc. under one or more contributor license agreements.
006     * See the AUTHORS.txt file in the distribution for a full listing of 
007     * individual contributors. 
008     *
009     * JBoss DNA is free software. Unless otherwise indicated, all code in JBoss DNA
010     * is licensed to you under the terms of the GNU Lesser General Public License as
011     * published by the Free Software Foundation; either version 2.1 of
012     * the License, or (at your option) any later version.
013     *
014     * JBoss DNA is distributed in the hope that it will be useful,
015     * but WITHOUT ANY WARRANTY; without even the implied warranty of
016     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
017     * Lesser General Public License for more details.
018     *
019     * You should have received a copy of the GNU Lesser General Public
020     * License along with this software; if not, write to the Free
021     * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
022     * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
023     */
024    package org.jboss.dna.web.jcr.rest;
025    
026    import java.util.Collection;
027    import javax.jcr.RepositoryException;
028    import javax.jcr.Session;
029    import javax.servlet.ServletContext;
030    import javax.servlet.http.HttpServletRequest;
031    import net.jcip.annotations.ThreadSafe;
032    import org.jboss.dna.common.util.CheckArg;
033    import org.jboss.dna.web.jcr.rest.spi.RepositoryProvider;
034    
035    /**
036     * Factory that provides implementations of the {@link RepositoryProvider repository provider SPI} by wrapping a
037     * {@link RepositoryProvider}.
038     * <p>
039     * The repository factory implements a lifecycle for the repository providers. It is first {@link #initialize(ServletContext)
040     * initialized} by {@link DnaJcrDeployer}, a servlet context listener that must be configured in the DNA JCR REST web
041     * configuration (web.xml). The repository factory looks in the context for a parameter with the name of {@link #PROVIDER_KEY}.
042     * This is assumed to be the FQN of the {@link RepositoryProvider repository provider}, which the factory will then instantiate.
043     * </p>
044     * <p>
045     * The repository factory is then able to respond to multiple requests to {@link #getJcrRepositoryNames() list the repository
046     * names} and {@link #getSession(HttpServletRequest, String, String) return active JCR sessions} until the {@link #shutdown()
047     * shutdown method} is called.
048     * </p>
049     * <p>
050     * The {@link #shutdown() shutdown method} is a simple proxy to the {@link RepositoryProvider#shutdown()} repository provider's
051     * shutdown method}.
052     * </p>
053     */
054    @ThreadSafe
055    public class RepositoryFactory {
056    
057        /** The FQN of the repository provider class. Currently set to {@value} . */
058        public static final String PROVIDER_KEY = "org.jboss.dna.web.jcr.rest.REPOSITORY_PROVIDER";
059    
060        private static RepositoryProvider provider;
061    
062        private RepositoryFactory() {
063    
064        }
065    
066        /**
067         * Initializes the repository factory. For more details, please see the {@link RepositoryFactory class-level documentation}.
068         * 
069         * @param context the servlet context; may not be null
070         * @see RepositoryFactory
071         */
072        static void initialize( ServletContext context ) {
073            CheckArg.isNotNull(context, "context");
074            String className = context.getInitParameter(PROVIDER_KEY);
075    
076            try {
077                Class<? extends RepositoryProvider> providerClass = Class.forName(className).asSubclass(RepositoryProvider.class);
078                provider = providerClass.newInstance();
079    
080            } catch (Exception ex) {
081                throw new IllegalStateException(ex);
082            }
083    
084            provider.startup(context);
085        }
086    
087        public static Session getSession( HttpServletRequest request,
088                                          String repositoryName,
089                                          String workspaceName ) throws RepositoryException {
090            return provider.getSession(request, repositoryName, workspaceName);
091        }
092    
093        public static Collection<String> getJcrRepositoryNames() {
094            return provider.getJcrRepositoryNames();
095        }
096    
097        static void shutdown() {
098            provider.shutdown();
099        }
100    }