001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.camel.component.file;
018    
019    import org.apache.camel.Exchange;
020    
021    /**
022     * Represents a pluggable strategy when processing files.
023     */
024    public interface GenericFileProcessStrategy<T> {
025    
026        /**
027         * Called when work is about to begin on this file. This method may attempt
028         * to acquire some file lock before returning true; returning false if the
029         * file lock could not be obtained so that the file should be ignored.
030         *
031         * @param operations ftp operations
032         * @param endpoint   the endpoint
033         * @param exchange   the exchange
034         * @param file       the remote file
035         * @return true if the file can be processed (such as if a file lock could
036         *         be obtained)
037         * @throws Exception can be thrown in case of errors
038         */
039        boolean begin(GenericFileOperations<T> operations, GenericFileEndpoint<T> endpoint,
040                Exchange exchange, GenericFile<T> file) throws Exception;
041    
042        /**
043         * Releases any file locks and possibly deletes or moves the file after
044         * successful processing
045         *
046         * @param operations ftp operations
047         * @param endpoint   the endpoint
048         * @param exchange   the exchange
049         * @param file       the remote file
050         * @throws Exception can be thrown in case of errors
051         */
052        void commit(GenericFileOperations<T> operations, GenericFileEndpoint<T> endpoint,
053                Exchange exchange, GenericFile<T> file) throws Exception;
054    
055        /**
056         * Releases any file locks and possibly deletes or moves the file after
057         * unsuccessful processing
058         *
059         * @param operations ftp operations
060         * @param endpoint   the endpoint
061         * @param exchange   the exchange
062         * @param file       the remote file
063         * @throws Exception can be thrown in case of errors
064         */
065        void rollback(GenericFileOperations<T> operations, GenericFileEndpoint<T> endpoint,
066                Exchange exchange, GenericFile<T> file) throws Exception;
067    
068    }