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.spi.Language;
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        protected String getFileSeparator() {
047            return File.separator;
048        }
049    
050        protected String normalizePath(String name) {        
051            return FileUtil.normalizePath(name);
052        }
053    
054        @SuppressWarnings("unchecked")
055        public void process(Exchange exchange) throws Exception {
056            Exchange fileExchange = endpoint.createExchange(exchange);
057            processExchange(fileExchange);
058            ExchangeHelper.copyResults(exchange, fileExchange);
059        }
060    
061        /**
062         * Perform the work to process the fileExchange
063         *
064         * @param exchange fileExchange
065         * @throws Exception is thrown if some error
066         */
067        protected void processExchange(Exchange exchange) throws Exception {
068            if (log.isTraceEnabled()) {
069                log.trace("Processing " + exchange);
070            }
071    
072            try {
073                String target = createFileName(exchange);
074    
075                preWriteCheck();
076    
077                // should we write to a temporary name and then afterwards rename to real target
078                boolean writeAsTempAndRename = ObjectHelper.isNotEmpty(endpoint.getTempFileName());
079                String tempTarget = null;
080                if (writeAsTempAndRename) {
081                    // compute temporary name with the temp prefix
082                    tempTarget = createTempFileName(exchange, target);
083    
084                    if (log.isTraceEnabled()) {
085                        log.trace("Writing using tempNameFile: " + tempTarget);
086                    }
087    
088                    // cater for file exists option on the real target as
089                    // the file operations code will work on the temp file
090    
091                    // if an existing file already exists what should we do?
092                    if (operations.existsFile(target)) {
093                        if (endpoint.getFileExist() == GenericFileExist.Ignore) {
094                            // ignore but indicate that the file was written
095                            if (log.isTraceEnabled()) {
096                                log.trace("An existing file already exists: " + target + ". Ignore and do not override it.");
097                            }
098                            return;
099                        } else if (endpoint.getFileExist() == GenericFileExist.Fail) {
100                            throw new GenericFileOperationFailedException("File already exist: " + target + ". Cannot write new file.");
101                        } else if (endpoint.getFileExist() == GenericFileExist.Override) {
102                            // we override the target so we do this by deleting it so the temp file can be renamed later
103                            // with success as the existing target file have been deleted
104                            if (log.isTraceEnabled()) {
105                                log.trace("Deleting existing file: " + tempTarget);
106                            }
107                            if (!operations.deleteFile(target)) {
108                                throw new GenericFileOperationFailedException("Cannot delete file: " + target);
109                            }
110    
111                        }
112                    }
113    
114                    // delete any pre existing temp file
115                    if (operations.existsFile(tempTarget)) {
116                        if (log.isTraceEnabled()) {
117                            log.trace("Deleting existing temp file: " + tempTarget);
118                        }
119                        if (!operations.deleteFile(tempTarget)) {
120                            throw new GenericFileOperationFailedException("Cannot delete file: " + tempTarget);
121                        }
122                    }
123                }
124    
125                // write/upload the file
126                writeFile(exchange, tempTarget != null ? tempTarget : target);
127    
128                // if we did write to a temporary name then rename it to the real
129                // name after we have written the file
130                if (tempTarget != null) {
131                    if (log.isTraceEnabled()) {
132                        log.trace("Renaming file: [" + tempTarget + "] to: [" + target + "]");
133                    }
134                    boolean renamed = operations.renameFile(tempTarget, target);
135                    if (!renamed) {
136                        throw new GenericFileOperationFailedException("Cannot rename file from: " + tempTarget + " to: " + target);
137                    }
138                }
139    
140                // lets store the name we really used in the header, so end-users
141                // can retrieve it
142                exchange.getIn().setHeader(Exchange.FILE_NAME_PRODUCED, target);
143            } catch (Exception e) {
144                handleFailedWrite(exchange, e);
145            }
146    
147            postWriteCheck();
148        }
149    
150        /**
151         * If we fail writing out a file, we will call this method. This hook is
152         * provided to disconnect from servers or clean up files we created (if needed).
153         */
154        protected void handleFailedWrite(Exchange exchange, Exception exception) throws Exception {
155            throw exception;
156        }
157    
158        /**
159         * Perform any actions that need to occur before we write such as connecting to an FTP server etc.
160         */
161        protected void preWriteCheck() throws Exception {
162            // nothing needed to check
163        }
164    
165        /**
166         * Perform any actions that need to occur after we are done such as disconnecting.
167         */
168        protected void postWriteCheck() {
169            // nothing needed to check
170        }
171    
172        protected void writeFile(Exchange exchange, String fileName) throws GenericFileOperationFailedException {
173            InputStream payload = exchange.getIn().getBody(InputStream.class);
174            try {
175                // build directory if auto create is enabled
176                if (endpoint.isAutoCreate()) {
177                    // use java.io.File to compute the file path
178                    File file = new File(fileName);
179                    String directory = file.getParent();
180                    boolean absolute = FileUtil.isAbsolute(file);
181                    if (directory != null) {
182                        if (!operations.buildDirectory(directory, absolute)) {
183                            if (log.isDebugEnabled()) {
184                                log.debug("Cannot build directory [" + directory + "] (could be because of denied permissions)");
185                            }
186                        }
187                    }
188                }
189    
190                // upload
191                if (log.isTraceEnabled()) {
192                    log.trace("About to write [" + fileName + "] to [" + getEndpoint() + "] from exchange [" + exchange + "]");
193                }
194    
195                boolean success = operations.storeFile(fileName, exchange);
196                if (!success) {
197                    throw new GenericFileOperationFailedException("Error writing file [" + fileName + "]");
198                }
199                if (log.isDebugEnabled()) {
200                    log.debug("Wrote [" + fileName + "] to [" + getEndpoint() + "]");
201                }
202    
203            } finally {
204                ObjectHelper.close(payload, "Closing payload", log);
205            }
206    
207        }
208    
209        protected String createFileName(Exchange exchange) {
210            String answer;
211    
212            String name = exchange.getIn().getHeader(Exchange.FILE_NAME, String.class);
213    
214            // expression support
215            Expression expression = endpoint.getFileName();
216            if (name != null) {
217                // the header name can be an expression too, that should override
218                // whatever configured on the endpoint
219                if (name.indexOf("${") > -1) {
220                    if (log.isDebugEnabled()) {
221                        log.debug(Exchange.FILE_NAME + " contains a FileLanguage expression: " + name);
222                    }
223                    Language language = getEndpoint().getCamelContext().resolveLanguage("file");
224                    expression = language.createExpression(name);
225                }
226            }
227            if (expression != null) {
228                if (log.isDebugEnabled()) {
229                    log.debug("Filename evaluated as expression: " + expression);
230                }
231                name = expression.evaluate(exchange, String.class);
232            }
233    
234            // flatten name
235            if (name != null && endpoint.isFlatten()) {
236                int pos = name.lastIndexOf(getFileSeparator());
237                if (pos == -1) {
238                    pos = name.lastIndexOf('/');
239                }
240                if (pos != -1) {
241                    name = name.substring(pos + 1);
242                }
243            }
244    
245            // compute path by adding endpoint starting directory
246            String endpointPath = endpoint.getConfiguration().getDirectory();
247            // Its a directory so we should use it as a base path for the filename
248            // If the path isn't empty, we need to add a trailing / if it isn't already there
249            String baseDir = "";
250            if (endpointPath.length() > 0) {
251                baseDir = endpointPath + (endpointPath.endsWith(getFileSeparator()) ? "" : getFileSeparator());
252            }
253            if (name != null) {
254                answer = baseDir + name;
255            } else {
256                // use a generated filename if no name provided
257                answer = baseDir + endpoint.getGeneratedFileName(exchange.getIn());
258            }
259    
260            // must normalize path to cater for Windows and other OS
261            answer = normalizePath(answer);
262    
263            return answer;
264        }
265    
266        protected String createTempFileName(Exchange exchange, String fileName) {
267            // must normalize path to cater for Windows and other OS
268            fileName = normalizePath(fileName);
269    
270            String tempName;
271            if (exchange.getIn().getHeader(Exchange.FILE_NAME) == null) {
272                // its a generated filename then add it to header so we can evaluate the expression
273                exchange.getIn().setHeader(Exchange.FILE_NAME, FileUtil.stripPath(fileName));
274                tempName = endpoint.getTempFileName().evaluate(exchange, String.class);
275                // and remove it again after evaluation
276                exchange.getIn().removeHeader(Exchange.FILE_NAME);
277            } else {
278                tempName = endpoint.getTempFileName().evaluate(exchange, String.class);
279            }
280    
281            int path = fileName.lastIndexOf(getFileSeparator());
282            if (path == -1) {
283                // no path
284                return tempName;
285            } else {
286                StringBuilder sb = new StringBuilder(fileName.substring(0, path + 1));
287                sb.append(tempName);
288                return sb.toString();
289            }
290        }
291    
292    }