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.connector.jdbc;
025    
026    import java.sql.Connection;
027    import java.sql.SQLException;
028    import java.util.UUID;
029    import java.util.concurrent.TimeUnit;
030    import javax.sql.XAConnection;
031    import javax.transaction.xa.XAResource;
032    import org.jboss.dna.common.util.Logger;
033    import org.jboss.dna.graph.ExecutionContext;
034    import org.jboss.dna.graph.cache.CachePolicy;
035    import org.jboss.dna.graph.connector.RepositoryConnection;
036    import org.jboss.dna.graph.connector.RepositorySourceException;
037    import org.jboss.dna.graph.request.Request;
038    import org.jboss.dna.graph.request.processor.RequestProcessor;
039    
040    /**
041     * JDBC connection wrapper
042     * 
043     * @author <a href="mailto:litsenko_sergey@yahoo.com">Sergiy Litsenko</a>
044     */
045    public class JdbcConnection implements RepositoryConnection {
046        /**
047         * Logging for this instance
048         */
049        protected Logger log = Logger.getLogger(getClass());
050    
051        private final String name;
052        private final CachePolicy cachePolicy;
053        private final Connection connection;
054        private final UUID rootNodeUuid;
055    
056        /*package*/JdbcConnection( String sourceName,
057                                    CachePolicy cachePolicy,
058                                    Connection connection,
059                                    UUID rootNodeUuid ) {
060            assert sourceName != null;
061            assert connection != null;
062            assert rootNodeUuid != null;
063            this.name = sourceName;
064            this.cachePolicy = cachePolicy; // may be null
065            this.connection = connection;
066            this.rootNodeUuid = rootNodeUuid;
067        }
068    
069        /**
070         * {@inheritDoc}
071         * 
072         * @see org.jboss.dna.graph.connector.RepositoryConnection#getSourceName()
073         */
074        public String getSourceName() {
075            return name;
076        }
077    
078        /**
079         * {@inheritDoc}
080         * 
081         * @see org.jboss.dna.graph.connector.RepositoryConnection#getDefaultCachePolicy()
082         */
083        public CachePolicy getDefaultCachePolicy() {
084            return cachePolicy;
085        }
086    
087        /**
088         * {@inheritDoc}
089         * 
090         * @see org.jboss.dna.graph.connector.RepositoryConnection#getXAResource()
091         */
092        public XAResource getXAResource() {
093            // if implemented by JDBC driver
094            if (connection instanceof XAConnection) {
095                try {
096                    return ((XAConnection)connection).getXAResource();
097                } catch (SQLException e) {
098                    // handle an exception silently so far and write it to the log
099                    log.error(e, JdbcMetadataI18n.unableToGetXAResource, getSourceName());
100                    return null;
101                }
102            }
103            // default
104            return null;
105        }
106    
107        /**
108         * {@inheritDoc}
109         * 
110         * @see org.jboss.dna.graph.connector.RepositoryConnection#ping(long, java.util.concurrent.TimeUnit)
111         */
112        public boolean ping( long time,
113                             TimeUnit unit ) {
114            try {
115                // JDBC 4 has a method to check validity of a connection (connection.isValid(timeout))
116                // but many drivers didn't get updated with latest spec
117                return connection != null && !connection.isClosed();
118            } catch (SQLException e) {
119                // debug
120                if (log.isDebugEnabled()) {
121                    log.debug(e, "{0}: Unable to check database connection due to error.", getSourceName());
122                }
123                return false;
124            }
125        }
126    
127        /**
128         * {@inheritDoc}
129         * 
130         * @see org.jboss.dna.graph.connector.RepositoryConnection#execute(org.jboss.dna.graph.ExecutionContext,
131         *      org.jboss.dna.graph.request.Request)
132         */
133        public void execute( ExecutionContext context,
134                             Request request ) throws RepositorySourceException {
135            // create processor and delegate handling
136            RequestProcessor proc = new JdbcRequestProcesor(getSourceName(), context, connection, rootNodeUuid);
137            try {
138                proc.process(request);
139            } finally {
140                proc.close();
141            }
142        }
143    
144        /**
145         * {@inheritDoc}
146         * 
147         * @see org.jboss.dna.graph.connector.RepositoryConnection#close()
148         */
149        public void close() {
150            try {
151                // release the JDBC connection resource
152                if (connection != null && !connection.isClosed()) {
153                    connection.close();
154                }
155            } catch (Exception e) {
156                // handle exception silently so far
157                if (log.isDebugEnabled()) {
158                    log.debug(e, "{0}: Unable to close database connection due to error.", getSourceName());
159                }
160            }
161        }
162    
163    }