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.getTempPrefix());
079                String tempTarget = null;
080                if (writeAsTempAndRename) {
081                    // compute temporary name with the temp prefix
082                    tempTarget = createTempFileName(target);
083                }
084    
085                // upload the file
086                writeFile(exchange, tempTarget != null ? tempTarget : target);
087    
088                // if we did write to a temporary name then rename it to the real
089                // name after we have written the file
090                if (tempTarget != null) {
091                    if (log.isTraceEnabled()) {
092                        log.trace("Renaming file: [" + tempTarget + "] to: [" + target + "]");
093                    }
094                    boolean renamed = operations.renameFile(tempTarget, target);
095                    if (!renamed) {
096                        throw new GenericFileOperationFailedException("Cannot rename file from: " + tempTarget + " to: " + target);
097                    }
098                }
099    
100                // lets store the name we really used in the header, so end-users
101                // can retrieve it
102                exchange.getIn().setHeader(Exchange.FILE_NAME_PRODUCED, target);
103            } catch (Exception e) {
104                handleFailedWrite(exchange, e);
105            }
106        }
107    
108        /**
109         * If we fail writing out a file, we will call this method. This hook is
110         * provided to disconnect from servers or clean up files we created (if needed).
111         */
112        protected void handleFailedWrite(Exchange exchange, Exception exception) throws Exception {
113            throw exception;
114        }
115    
116        /**
117         * Perform any actions that need to occur before we write such as connecting to an FTP server etc.
118         */
119        protected void preWriteCheck() throws Exception {
120        }
121    
122        protected void writeFile(Exchange exchange, String fileName) throws GenericFileOperationFailedException {
123            InputStream payload = exchange.getIn().getBody(InputStream.class);
124            try {
125                // build directory if auto create is enabled
126                if (endpoint.isAutoCreate()) {
127                    // use java.io.File to compute the file path
128                    File file = new File(fileName);
129                    String directory = file.getParent();
130                    boolean absolute = file.isAbsolute();
131                    if (directory != null) {
132                        if (!operations.buildDirectory(directory, absolute)) {
133                            log.debug("Cannot build directory [" + directory + "] (could be because of denied permissions)");
134                        }
135                    }
136                }
137    
138                // upload
139                if (log.isTraceEnabled()) {
140                    log.trace("About to write [" + fileName + "] to [" + getEndpoint() + "] from exchange [" + exchange + "]");
141                }
142    
143                boolean success = operations.storeFile(fileName, exchange);
144                if (!success) {
145                    throw new GenericFileOperationFailedException("Error writing file [" + fileName + "]");
146                }
147                if (log.isDebugEnabled()) {
148                    log.debug("Wrote [" + fileName + "] to [" + getEndpoint() + "]");
149                }
150    
151            } finally {
152                ObjectHelper.close(payload, "Closing payload", log);
153            }
154    
155        }
156    
157        protected String createFileName(Exchange exchange) {
158            String answer;
159    
160            String name = exchange.getIn().getHeader(Exchange.FILE_NAME, String.class);
161    
162            // expression support
163            Expression expression = endpoint.getFileName();
164            if (name != null) {
165                // the header name can be an expression too, that should override
166                // whatever configured on the endpoint
167                if (name.indexOf("${") > -1) {
168                    if (log.isDebugEnabled()) {
169                        log.debug(Exchange.FILE_NAME + " contains a FileLanguage expression: " + name);
170                    }
171                    Language language = getEndpoint().getCamelContext().resolveLanguage("file");
172                    expression = language.createExpression(name);
173                }
174            }
175            if (expression != null) {
176                if (log.isDebugEnabled()) {
177                    log.debug("Filename evaluated as expression: " + expression);
178                }
179                name = expression.evaluate(exchange, String.class);
180            }
181    
182            // flatten name
183            if (name != null && endpoint.isFlatten()) {
184                int pos = name.lastIndexOf(getFileSeparator());
185                if (pos == -1) {
186                    pos = name.lastIndexOf('/');
187                }
188                if (pos != -1) {
189                    name = name.substring(pos + 1);
190                }
191            }
192    
193            // compute path by adding endpoint starting directory
194            String endpointPath = endpoint.getConfiguration().getDirectory();
195            // Its a directory so we should use it as a base path for the filename
196            // If the path isn't empty, we need to add a trailing / if it isn't already there
197            String baseDir = "";
198            if (endpointPath.length() > 0) {
199                baseDir = endpointPath + (endpointPath.endsWith(getFileSeparator()) ? "" : getFileSeparator());
200            }
201            if (name != null) {
202                answer = baseDir + name;
203            } else {
204                // use a generated filename if no name provided
205                answer = baseDir + endpoint.getGeneratedFileName(exchange.getIn());
206            }
207    
208            // must normalize path to cater for Windows and other OS
209            answer = normalizePath(answer);
210    
211            return answer;
212        }
213    
214        protected String createTempFileName(String fileName) {
215            // must normalize path to cater for Windows and other OS
216            fileName = normalizePath(fileName);
217    
218            int path = fileName.lastIndexOf(getFileSeparator());
219            if (path == -1) {
220                // no path
221                return endpoint.getTempPrefix() + fileName;
222            } else {
223                StringBuilder sb = new StringBuilder(fileName);
224                sb.insert(path + 1, endpoint.getTempPrefix());
225                return sb.toString();
226            }
227        }
228    
229    }