001    package org.apache.archiva.transaction;
002    
003    /*
004     * Licensed to the Apache Software Foundation (ASF) under one
005     * or more contributor license agreements.  See the NOTICE file
006     * distributed with this work for additional information
007     * regarding copyright ownership.  The ASF licenses this file
008     * to you under the Apache License, Version 2.0 (the
009     * "License"); you may not use this file except in compliance
010     * with the License.  You may obtain a copy of the License at
011     *
012     *   http://www.apache.org/licenses/LICENSE-2.0
013     *
014     * Unless required by applicable law or agreed to in writing,
015     * software distributed under the License is distributed on an
016     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017     * KIND, either express or implied.  See the License for the
018     * specific language governing permissions and limitations
019     * under the License.
020     */
021    
022    import java.io.File;
023    import java.io.IOException;
024    import java.util.ArrayList;
025    import java.util.List;
026    
027    import org.codehaus.plexus.digest.Digester;
028    
029    /**
030     * Implement commit/rollback semantics for a set of files.
031     *
032     */
033    public class FileTransaction
034    {
035        private List<AbstractTransactionEvent> events = new ArrayList<AbstractTransactionEvent>();
036    
037        public void commit()
038            throws TransactionException
039        {
040            List<TransactionEvent> toRollback = new ArrayList<TransactionEvent>( events.size() );
041    
042            for ( TransactionEvent event : events )
043            {
044                try
045                {
046                    event.commit();
047    
048                    toRollback.add( event );
049                }
050                catch ( IOException e )
051                {
052                    try
053                    {
054                        rollback( toRollback );
055    
056                        throw new TransactionException( "Unable to commit file transaction", e );
057                    }
058                    catch ( IOException ioe )
059                    {
060                        throw new TransactionException(
061                            "Unable to commit file transaction, and rollback failed with error: '" + ioe.getMessage() + "'",
062                            e );
063                    }
064                }
065            }
066        }
067    
068        private void rollback( List<TransactionEvent> toRollback )
069            throws IOException
070        {
071            for ( TransactionEvent event : toRollback )
072            {
073                event.rollback();
074            }
075        }
076    
077        /**
078         * @param source
079         * @param destination
080         * @param digesters   {@link List}&lt;{@link org.codehaus.plexus.digest.Digester}> digesters to use for checksumming
081         */
082        public void copyFile( File source, File destination, List<? extends Digester> digesters )
083        {
084            events.add( new CopyFileEvent( source, destination, digesters ) );
085        }
086    
087        /**
088         * @param content
089         * @param destination
090         * @param digesters   {@link List}&lt;{@link org.codehaus.plexus.digest.Digester}> digesters to use for checksumming
091         */
092        public void createFile( String content, File destination, List<? extends Digester> digesters )
093        {
094            events.add( new CreateFileEvent( content, destination, digesters ) );
095        }
096    }