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.util.concurrent.locks.Lock;
021 import java.util.concurrent.locks.ReentrantLock;
022
023 import org.apache.camel.Exchange;
024 import org.apache.camel.Expression;
025 import org.apache.camel.impl.DefaultExchange;
026 import org.apache.camel.impl.DefaultProducer;
027 import org.apache.camel.spi.Language;
028 import org.apache.camel.util.FileUtil;
029 import org.apache.camel.util.LRUCache;
030 import org.apache.camel.util.ObjectHelper;
031 import org.apache.camel.util.ServiceHelper;
032 import org.apache.camel.util.StringHelper;
033 import org.slf4j.Logger;
034 import org.slf4j.LoggerFactory;
035
036 /**
037 * Generic file producer
038 */
039 public class GenericFileProducer<T> extends DefaultProducer {
040 protected final transient Logger log = LoggerFactory.getLogger(getClass());
041 protected final GenericFileEndpoint<T> endpoint;
042 protected GenericFileOperations<T> operations;
043 // assume writing to 100 different files concurrently at most for the same file producer
044 private final LRUCache<String, Lock> locks = new LRUCache<String, Lock>(100);
045
046 protected GenericFileProducer(GenericFileEndpoint<T> endpoint, GenericFileOperations<T> operations) {
047 super(endpoint);
048 this.endpoint = endpoint;
049 this.operations = operations;
050 }
051
052 public String getFileSeparator() {
053 return File.separator;
054 }
055
056 public String normalizePath(String name) {
057 return FileUtil.normalizePath(name);
058 }
059
060 public void process(Exchange exchange) throws Exception {
061 String target = createFileName(exchange);
062
063 // use lock for same file name to avoid concurrent writes to the same file
064 // for example when you concurrently append to the same file
065 Lock lock;
066 synchronized (locks) {
067 lock = locks.get(target);
068 if (lock == null) {
069 lock = new ReentrantLock();
070 locks.put(target, lock);
071 }
072 }
073
074 lock.lock();
075 try {
076 processExchange(exchange, target);
077 } finally {
078 // do not remove as the locks cache has an upper bound
079 // this ensure the locks is appropriate reused
080 lock.unlock();
081 }
082 }
083
084 /**
085 * Sets the operations to be used.
086 * <p/>
087 * Can be used to set a fresh operations in case of recovery attempts
088 *
089 * @param operations the operations
090 */
091 public void setOperations(GenericFileOperations<T> operations) {
092 this.operations = operations;
093 }
094
095 /**
096 * Perform the work to process the fileExchange
097 *
098 * @param exchange fileExchange
099 * @param target the target filename
100 * @throws Exception is thrown if some error
101 */
102 protected void processExchange(Exchange exchange, String target) throws Exception {
103 log.trace("Processing file: {} for exchange: {}", target, exchange);
104
105 try {
106 preWriteCheck();
107
108 // should we write to a temporary name and then afterwards rename to real target
109 boolean writeAsTempAndRename = ObjectHelper.isNotEmpty(endpoint.getTempFileName());
110 String tempTarget = null;
111 // remember if target exists to avoid checking twice
112 Boolean targetExists = null;
113 if (writeAsTempAndRename) {
114 // compute temporary name with the temp prefix
115 tempTarget = createTempFileName(exchange, target);
116
117 log.trace("Writing using tempNameFile: {}", tempTarget);
118
119 // cater for file exists option on the real target as
120 // the file operations code will work on the temp file
121
122 // if an existing file already exists what should we do?
123 targetExists = operations.existsFile(target);
124 if (targetExists) {
125 if (endpoint.getFileExist() == GenericFileExist.Ignore) {
126 // ignore but indicate that the file was written
127 log.trace("An existing file already exists: {}. Ignore and do not override it.", target);
128 return;
129 } else if (endpoint.getFileExist() == GenericFileExist.Fail) {
130 throw new GenericFileOperationFailedException("File already exist: " + target + ". Cannot write new file.");
131 } else if (endpoint.isEagerDeleteTargetFile() && endpoint.getFileExist() == GenericFileExist.Override) {
132 // we override the target so we do this by deleting it so the temp file can be renamed later
133 // with success as the existing target file have been deleted
134 log.trace("Eagerly deleting existing file: {}", target);
135 if (!operations.deleteFile(target)) {
136 throw new GenericFileOperationFailedException("Cannot delete file: " + target);
137 }
138 }
139 }
140
141 // delete any pre existing temp file
142 if (operations.existsFile(tempTarget)) {
143 log.trace("Deleting existing temp file: {}", tempTarget);
144 if (!operations.deleteFile(tempTarget)) {
145 throw new GenericFileOperationFailedException("Cannot delete file: " + tempTarget);
146 }
147 }
148 }
149
150 // write/upload the file
151 writeFile(exchange, tempTarget != null ? tempTarget : target);
152
153 // if we did write to a temporary name then rename it to the real
154 // name after we have written the file
155 if (tempTarget != null) {
156
157 // if we should not eager delete the target file then do it now just before renaming
158 if (!endpoint.isEagerDeleteTargetFile() && targetExists
159 && endpoint.getFileExist() == GenericFileExist.Override) {
160 // we override the target so we do this by deleting it so the temp file can be renamed later
161 // with success as the existing target file have been deleted
162 log.trace("Deleting existing file: {}", target);
163 if (!operations.deleteFile(target)) {
164 throw new GenericFileOperationFailedException("Cannot delete file: " + target);
165 }
166 }
167
168 // now we are ready to rename the temp file to the target file
169 log.trace("Renaming file: [{}] to: [{}]", tempTarget, target);
170 boolean renamed = operations.renameFile(tempTarget, target);
171 if (!renamed) {
172 throw new GenericFileOperationFailedException("Cannot rename file from: " + tempTarget + " to: " + target);
173 }
174 }
175
176 // any done file to write?
177 if (endpoint.getDoneFileName() != null) {
178 String doneFileName = endpoint.createDoneFileName(target);
179 ObjectHelper.notEmpty(doneFileName, "doneFileName", endpoint);
180
181 // create empty exchange with empty body to write as the done file
182 Exchange empty = new DefaultExchange(exchange);
183 empty.getIn().setBody("");
184
185 log.trace("Writing done file: [{}]", doneFileName);
186 // delete any existing done file
187 if (operations.existsFile(doneFileName)) {
188 if (!operations.deleteFile(doneFileName)) {
189 throw new GenericFileOperationFailedException("Cannot delete existing done file: " + doneFileName);
190 }
191 }
192 writeFile(empty, doneFileName);
193 }
194
195 // let's store the name we really used in the header, so end-users
196 // can retrieve it
197 exchange.getIn().setHeader(Exchange.FILE_NAME_PRODUCED, target);
198 } catch (Exception e) {
199 handleFailedWrite(exchange, e);
200 }
201
202 postWriteCheck();
203 }
204
205 /**
206 * If we fail writing out a file, we will call this method. This hook is
207 * provided to disconnect from servers or clean up files we created (if needed).
208 */
209 public void handleFailedWrite(Exchange exchange, Exception exception) throws Exception {
210 throw exception;
211 }
212
213 /**
214 * Perform any actions that need to occur before we write such as connecting to an FTP server etc.
215 */
216 public void preWriteCheck() throws Exception {
217 // nothing needed to check
218 }
219
220 /**
221 * Perform any actions that need to occur after we are done such as disconnecting.
222 */
223 public void postWriteCheck() {
224 // nothing needed to check
225 }
226
227 public void writeFile(Exchange exchange, String fileName) throws GenericFileOperationFailedException {
228 // build directory if auto create is enabled
229 if (endpoint.isAutoCreate()) {
230 // we must normalize it (to avoid having both \ and / in the name which confuses java.io.File)
231 String name = FileUtil.normalizePath(fileName);
232
233 // use java.io.File to compute the file path
234 File file = new File(name);
235 String directory = file.getParent();
236 boolean absolute = FileUtil.isAbsolute(file);
237 if (directory != null) {
238 if (!operations.buildDirectory(directory, absolute)) {
239 log.debug("Cannot build directory [{}] (could be because of denied permissions)", directory);
240 }
241 }
242 }
243
244 // upload
245 if (log.isTraceEnabled()) {
246 log.trace("About to write [{}] to [{}] from exchange [{}]", new Object[]{fileName, getEndpoint(), exchange});
247 }
248
249 boolean success = operations.storeFile(fileName, exchange);
250 if (!success) {
251 throw new GenericFileOperationFailedException("Error writing file [" + fileName + "]");
252 }
253 log.debug("Wrote [{}] to [{}]", fileName, getEndpoint());
254 }
255
256 public String createFileName(Exchange exchange) {
257 String answer;
258
259 String name = exchange.getIn().getHeader(Exchange.FILE_NAME, String.class);
260
261 // expression support
262 Expression expression = endpoint.getFileName();
263 if (name != null) {
264 // the header name can be an expression too, that should override
265 // whatever configured on the endpoint
266 if (StringHelper.hasStartToken(name, "simple")) {
267 log.trace("{} contains a Simple expression: {}", Exchange.FILE_NAME, name);
268 Language language = getEndpoint().getCamelContext().resolveLanguage("file");
269 expression = language.createExpression(name);
270 }
271 }
272 if (expression != null) {
273 log.trace("Filename evaluated as expression: {}", expression);
274 name = expression.evaluate(exchange, String.class);
275 }
276
277 // flatten name
278 if (name != null && endpoint.isFlatten()) {
279 // check for both windows and unix separators
280 int pos = Math.max(name.lastIndexOf("/"), name.lastIndexOf("\\"));
281 if (pos != -1) {
282 name = name.substring(pos + 1);
283 }
284 }
285
286 // compute path by adding endpoint starting directory
287 String endpointPath = endpoint.getConfiguration().getDirectory();
288 String baseDir = "";
289 if (endpointPath.length() > 0) {
290 // Its a directory so we should use it as a base path for the filename
291 // If the path isn't empty, we need to add a trailing / if it isn't already there
292 baseDir = endpointPath;
293 boolean trailingSlash = endpointPath.endsWith("/") || endpointPath.endsWith("\\");
294 if (!trailingSlash) {
295 baseDir += getFileSeparator();
296 }
297 }
298 if (name != null) {
299 answer = baseDir + name;
300 } else {
301 // use a generated filename if no name provided
302 answer = baseDir + endpoint.getGeneratedFileName(exchange.getIn());
303 }
304
305 if (endpoint.getConfiguration().needToNormalize()) {
306 // must normalize path to cater for Windows and other OS
307 answer = normalizePath(answer);
308 }
309
310 return answer;
311 }
312
313 public String createTempFileName(Exchange exchange, String fileName) {
314 String answer = fileName;
315
316 String tempName;
317 if (exchange.getIn().getHeader(Exchange.FILE_NAME) == null) {
318 // its a generated filename then add it to header so we can evaluate the expression
319 exchange.getIn().setHeader(Exchange.FILE_NAME, FileUtil.stripPath(fileName));
320 tempName = endpoint.getTempFileName().evaluate(exchange, String.class);
321 // and remove it again after evaluation
322 exchange.getIn().removeHeader(Exchange.FILE_NAME);
323 } else {
324 tempName = endpoint.getTempFileName().evaluate(exchange, String.class);
325 }
326
327 // check for both windows and unix separators
328 int pos = Math.max(answer.lastIndexOf("/"), answer.lastIndexOf("\\"));
329 if (pos == -1) {
330 // no path so use temp name as calculated
331 answer = tempName;
332 } else {
333 // path should be prefixed before the temp name
334 StringBuilder sb = new StringBuilder(answer.substring(0, pos + 1));
335 sb.append(tempName);
336 answer = sb.toString();
337 }
338
339 if (endpoint.getConfiguration().needToNormalize()) {
340 // must normalize path to cater for Windows and other OS
341 answer = normalizePath(answer);
342 }
343
344 return answer;
345 }
346
347 @Override
348 protected void doStart() throws Exception {
349 super.doStart();
350 ServiceHelper.startService(locks);
351 }
352
353 @Override
354 protected void doStop() throws Exception {
355 ServiceHelper.stopService(locks);
356 super.doStop();
357 }
358 }