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 java.io.File;
020    import java.io.InputStream;
021    
022    import org.apache.camel.Exchange;
023    import org.apache.camel.Expression;
024    import org.apache.camel.impl.DefaultProducer;
025    import org.apache.camel.language.simple.FileLanguage;
026    import org.apache.camel.util.ExchangeHelper;
027    import org.apache.camel.util.FileUtil;
028    import org.apache.camel.util.ObjectHelper;
029    import org.apache.commons.logging.Log;
030    import org.apache.commons.logging.LogFactory;
031    
032    /**
033     * Generic file producer
034     */
035    public class GenericFileProducer<T> extends DefaultProducer {
036        protected final transient Log log = LogFactory.getLog(getClass());
037        protected final GenericFileEndpoint<T> endpoint;
038        protected final GenericFileOperations<T> operations;
039    
040        protected GenericFileProducer(GenericFileEndpoint<T> endpoint, GenericFileOperations<T> operations) {
041            super(endpoint);
042            this.endpoint = endpoint;
043            this.operations = operations;
044        }
045    
046        @SuppressWarnings("unchecked")
047        public void process(Exchange exchange) throws Exception {
048            GenericFileExchange<T> fileExchange = (GenericFileExchange<T>) endpoint.createExchange(exchange);
049            processExchange(fileExchange);
050            ExchangeHelper.copyResults(exchange, fileExchange);
051        }
052    
053        /**
054         * Perform the work to process the fileExchange
055         *
056         * @param exchange fileExchange
057         * @throws Exception is thrown if some error
058         */
059        protected void processExchange(GenericFileExchange<T> exchange) throws Exception {
060            if (log.isTraceEnabled()) {
061                log.trace("Processing " + exchange);
062            }
063    
064            try {
065                String target = createFileName(exchange);
066    
067                preWriteCheck();
068    
069                // should we write to a temporary name and then afterwards rename to real target
070                boolean writeAsTempAndRename = ObjectHelper.isNotEmpty(endpoint.getTempPrefix());
071                String tempTarget = null;
072                if (writeAsTempAndRename) {
073                    // compute temporary name with the temp prefix
074                    tempTarget = createTempFileName(target);
075                }
076    
077                // upload the file
078                writeFile(exchange, tempTarget != null ? tempTarget : target);
079    
080                // if we did write to a temporary name then rename it to the real
081                // name after we have written the file
082                if (tempTarget != null) {
083                    if (log.isTraceEnabled()) {
084                        log.trace("Renaming file: [" + tempTarget + "] to: [" + target + "]");
085                    }
086                    boolean renamed = operations.renameFile(tempTarget, target);
087                    if (!renamed) {
088                        throw new GenericFileOperationFailedException("Cannot rename file from: " + tempTarget + " to: " + target);
089                    }
090                }
091    
092                // lets store the name we really used in the header, so end-users
093                // can retrieve it
094                exchange.getIn().setHeader(Exchange.FILE_NAME_PRODUCED, target);
095            } catch (Exception e) {
096                handleFailedWrite(exchange, e);
097            }
098        }
099    
100        /**
101         * If we fail writing out a file, we will call this method. This hook is
102         * provided to disconnect from servers or clean up files we created (if needed).
103         */
104        protected void handleFailedWrite(GenericFileExchange<T> exchange, Exception exception) throws Exception {
105            throw exception;
106        }
107    
108        /**
109         * Perform any actions that need to occur before we write such as connecting to an FTP server etc.
110         */
111        protected void preWriteCheck() throws Exception {
112        }
113    
114        protected void writeFile(GenericFileExchange<T> exchange, String fileName) throws GenericFileOperationFailedException {
115            InputStream payload = exchange.getIn().getBody(InputStream.class);
116            try {
117                // build directory if auto create is enabled
118                if (endpoint.isAutoCreate()) {
119                    int lastPathIndex = fileName.lastIndexOf(File.separator);
120                    if (lastPathIndex != -1) {
121                        String directory = fileName.substring(0, lastPathIndex);
122                        // skip trailing /
123                        directory = FileUtil.stripLeadingSeparator(directory);
124                        if (!operations.buildDirectory(directory, false)) {
125                            log.debug("Cannot build directory [" + directory + "] (could be because of denied permissions)");
126                        }
127                    }
128                }
129    
130                // upload
131                if (log.isTraceEnabled()) {
132                    log.trace("About to write [" + fileName + "] to [" + getEndpoint() + "] from exchange [" + exchange + "]");
133                }
134    
135                boolean success = operations.storeFile(fileName, exchange);
136                if (!success) {
137                    throw new GenericFileOperationFailedException("Error writing file [" + fileName + "]");
138                }
139                if (log.isDebugEnabled()) {
140                    log.debug("Wrote [" + fileName + "] to [" + getEndpoint() + "]");
141                }
142    
143            } finally {
144                ObjectHelper.close(payload, "Closing payload", log);
145            }
146    
147        }
148    
149        protected String createFileName(Exchange exchange) {
150            String answer;
151    
152            String name = exchange.getIn().getHeader(Exchange.FILE_NAME, String.class);
153    
154            // expression support
155            Expression expression = endpoint.getFileName();
156            if (name != null) {
157                // the header name can be an expression too, that should override
158                // whatever configured on the endpoint
159                if (name.indexOf("${") > -1) {
160                    if (log.isDebugEnabled()) {
161                        log.debug(Exchange.FILE_NAME + " contains a FileLanguage expression: " + name);
162                    }
163                    expression = FileLanguage.file(name);
164                }
165            }
166            if (expression != null) {
167                if (log.isDebugEnabled()) {
168                    log.debug("Filename evaluated as expression: " + expression);
169                }
170                name = expression.evaluate(exchange, String.class);
171            }
172    
173    
174            // flattern name
175            if (endpoint.isFlattern()) {
176                int pos = name.lastIndexOf(File.separator);
177                if (pos == -1) {
178                    pos = name.lastIndexOf('/');
179                }
180                if (pos != -1) {
181                    name = name.substring(pos + 1);
182                }
183            }
184    
185            // compute path by adding endpoint starting directory
186            String endpointPath = endpoint.getConfiguration().getDirectory();
187            // Its a directory so we should use it as a base path for the filename
188            // If the path isn't empty, we need to add a trailing / if it isn't already there
189            String baseDir = "";
190            if (endpointPath.length() > 0) {
191                baseDir = endpointPath + (endpointPath.endsWith(File.separator) ? "" : File.separator);
192            }
193            if (name != null) {
194                answer = baseDir + name;
195            } else {
196                // use a generated filename if no name provided
197                answer = baseDir + endpoint.getGeneratedFileName(exchange.getIn());
198            }
199    
200            // must normalize path to cater for Windows and other OS
201            answer = FileUtil.normalizePath(answer);
202    
203            return answer;
204        }
205    
206        protected String createTempFileName(String fileName) {
207            // must normalize path to cater for Windows and other OS
208            fileName = FileUtil.normalizePath(fileName);
209    
210            int path = fileName.lastIndexOf(File.separator);
211            if (path == -1) {
212                // no path
213                return endpoint.getTempPrefix() + fileName;
214            } else {
215                StringBuilder sb = new StringBuilder(fileName);
216                sb.insert(path + 1, endpoint.getTempPrefix());
217                return sb.toString();
218            }
219        }
220    
221    }