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 */
017package org.apache.camel.util;
018
019import java.io.File;
020import java.io.IOException;
021import java.nio.file.Files;
022import java.nio.file.StandardCopyOption;
023import java.util.ArrayDeque;
024import java.util.Deque;
025import java.util.Iterator;
026import java.util.Locale;
027import java.util.Objects;
028
029import org.slf4j.Logger;
030import org.slf4j.LoggerFactory;
031
032/**
033 * File utilities.
034 */
035public final class FileUtil {
036
037    public static final int BUFFER_SIZE = 128 * 1024;
038
039    private static final Logger LOG = LoggerFactory.getLogger(FileUtil.class);
040    private static final int RETRY_SLEEP_MILLIS = 10;
041    /**
042     * The System property key for the user directory.
043     */
044    private static final String USER_DIR_KEY = "user.dir";
045    private static final File USER_DIR = new File(System.getProperty(USER_DIR_KEY));
046    private static boolean windowsOs = initWindowsOs();
047
048    private FileUtil() {
049        // Utils method
050    }
051
052    private static boolean initWindowsOs() {
053        // initialize once as System.getProperty is not fast
054        String osName = System.getProperty("os.name").toLowerCase(Locale.ENGLISH);
055        return osName.contains("windows");
056    }
057
058    public static File getUserDir() {
059        return USER_DIR;
060    }
061
062    /**
063     * Normalizes the path to cater for Windows and other platforms
064     */
065    public static String normalizePath(String path) {
066        if (path == null) {
067            return null;
068        }
069
070        if (isWindows()) {
071            // special handling for Windows where we need to convert / to \\
072            return path.replace('/', '\\');
073        } else {
074            // for other systems make sure we use / as separators
075            return path.replace('\\', '/');
076        }
077    }
078
079    /**
080     * Returns true, if the OS is windows
081     */
082    public static boolean isWindows() {
083        return windowsOs;
084    }
085
086    public static File createTempFile(String prefix, String suffix, File parentDir) throws IOException {
087        Objects.requireNonNull(parentDir);
088
089        if (suffix == null) {
090            suffix = ".tmp";
091        }
092        if (prefix == null) {
093            prefix = "camel";
094        } else if (prefix.length() < 3) {
095            prefix = prefix + "camel";
096        }
097
098        // create parent folder
099        parentDir.mkdirs();
100
101        return Files.createTempFile(parentDir.toPath(), prefix, suffix).toFile();
102    }
103
104    /**
105     * Strip any leading separators
106     */
107    public static String stripLeadingSeparator(String name) {
108        if (name == null) {
109            return null;
110        }
111        while (name.startsWith("/") || name.startsWith(File.separator)) {
112            name = name.substring(1);
113        }
114        return name;
115    }
116
117    /**
118     * Does the name start with a leading separator
119     */
120    public static boolean hasLeadingSeparator(String name) {
121        if (name == null) {
122            return false;
123        }
124        if (name.startsWith("/") || name.startsWith(File.separator)) {
125            return true;
126        }
127        return false;
128    }
129
130    /**
131     * Strip first leading separator
132     */
133    public static String stripFirstLeadingSeparator(String name) {
134        if (name == null) {
135            return null;
136        }
137        if (name.startsWith("/") || name.startsWith(File.separator)) {
138            name = name.substring(1);
139        }
140        return name;
141    }
142
143    /**
144     * Strip any trailing separators
145     */
146    public static String stripTrailingSeparator(String name) {
147        if (ObjectHelper.isEmpty(name)) {
148            return name;
149        }
150
151        String s = name;
152
153        // there must be some leading text, as we should only remove trailing separators 
154        while (s.endsWith("/") || s.endsWith(File.separator)) {
155            s = s.substring(0, s.length() - 1);
156        }
157
158        // if the string is empty, that means there was only trailing slashes, and no leading text
159        // and so we should then return the original name as is
160        if (ObjectHelper.isEmpty(s)) {
161            return name;
162        } else {
163            // return without trailing slashes
164            return s;
165        }
166    }
167
168    /**
169     * Strips any leading paths
170     */
171    public static String stripPath(String name) {
172        if (name == null) {
173            return null;
174        }
175        int posUnix = name.lastIndexOf('/');
176        int posWin = name.lastIndexOf('\\');
177        int pos = Math.max(posUnix, posWin);
178
179        if (pos != -1) {
180            return name.substring(pos + 1);
181        }
182        return name;
183    }
184
185    public static String stripExt(String name) {
186        return stripExt(name, false);
187    }
188
189    public static String stripExt(String name, boolean singleMode) {
190        if (name == null) {
191            return null;
192        }
193
194        // the name may have a leading path
195        int posUnix = name.lastIndexOf('/');
196        int posWin = name.lastIndexOf('\\');
197        int pos = Math.max(posUnix, posWin);
198
199        if (pos > 0) {
200            String onlyName = name.substring(pos + 1);
201            int pos2 = singleMode ? onlyName.lastIndexOf('.') : onlyName.indexOf('.');
202            if (pos2 > 0) {
203                return name.substring(0, pos + pos2 + 1);
204            }
205        } else {
206            // if single ext mode, then only return last extension
207            int pos2 = singleMode ? name.lastIndexOf('.') : name.indexOf('.');
208            if (pos2 > 0) {
209                return name.substring(0, pos2);
210            }
211        }
212
213        return name;
214    }
215
216    public static String onlyExt(String name) {
217        return onlyExt(name, false);
218    }
219
220    public static String onlyExt(String name, boolean singleMode) {
221        if (name == null) {
222            return null;
223        }
224        name = stripPath(name);
225
226        // extension is the first dot, as a file may have double extension such as .tar.gz
227        // if single ext mode, then only return last extension
228        int pos = singleMode ? name.lastIndexOf('.') : name.indexOf('.');
229        if (pos != -1) {
230            return name.substring(pos + 1);
231        }
232        return null;
233    }
234
235    /**
236     * Returns only the leading path (returns <tt>null</tt> if no path)
237     */
238    public static String onlyPath(String name) {
239        if (name == null) {
240            return null;
241        }
242
243        int posUnix = name.lastIndexOf('/');
244        int posWin = name.lastIndexOf('\\');
245        int pos = Math.max(posUnix, posWin);
246
247        if (pos > 0) {
248            return name.substring(0, pos);
249        } else if (pos == 0) {
250            // name is in the root path, so extract the path as the first char
251            return name.substring(0, 1);
252        }
253        // no path in name
254        return null;
255    }
256
257    /**
258     * Compacts a path by stacking it and reducing <tt>..</tt>, and uses OS specific file separators (eg
259     * {@link java.io.File#separator}).
260     */
261    public static String compactPath(String path) {
262        return compactPath(path, "" + File.separatorChar);
263    }
264
265    /**
266     * Compacts a path by stacking it and reducing <tt>..</tt>, and uses the given separator.
267     *
268     */
269    public static String compactPath(String path, char separator) {
270        return compactPath(path, "" + separator);
271    }
272
273    /**
274     * Compacts a file path by stacking it and reducing <tt>..</tt>, and uses the given separator.
275     */
276    public static String compactPath(String path, String separator) {
277        if (path == null) {
278            return null;
279        }
280
281        if (path.startsWith("http:")) {
282            return path;
283        }
284
285        // only normalize if contains a path separator
286        if (path.indexOf('/') == -1 && path.indexOf('\\') == -1) {
287            return path;
288        }
289
290        // need to normalize path before compacting
291        path = normalizePath(path);
292
293        // preserve ending slash if given in input path
294        boolean endsWithSlash = path.endsWith("/") || path.endsWith("\\");
295
296        // preserve starting slash if given in input path
297        int cntSlashsAtStart = 0;
298        if (path.startsWith("/") || path.startsWith("\\")) {
299            cntSlashsAtStart++;
300            // for Windows, preserve up to 2 starting slashes, which is necessary for UNC paths.
301            if (isWindows() && path.length() > 1 && (path.charAt(1) == '/' || path.charAt(1) == '\\')) {
302                cntSlashsAtStart++;
303            }
304        }
305
306        Deque<String> stack = new ArrayDeque<>();
307
308        // separator can either be windows or unix style
309        String separatorRegex = "\\\\|/";
310        String[] parts = path.split(separatorRegex);
311        for (String part : parts) {
312            if (part.equals("..") && !stack.isEmpty() && !"..".equals(stack.peek())) {
313                // only pop if there is a previous path, which is not a ".." path either
314                stack.pop();
315            } else if (part.equals(".") || part.isEmpty()) {
316                // do nothing because we don't want a path like foo/./bar or foo//bar
317            } else {
318                stack.push(part);
319            }
320        }
321
322        // build path based on stack
323        StringBuilder sb = new StringBuilder();
324
325        for (int i = 0; i < cntSlashsAtStart; i++) {
326            sb.append(separator);
327        }
328
329        // now we build back using FIFO so need to use descending
330        for (Iterator<String> it = stack.descendingIterator(); it.hasNext();) {
331            sb.append(it.next());
332            if (it.hasNext()) {
333                sb.append(separator);
334            }
335        }
336
337        if (endsWithSlash && !stack.isEmpty()) {
338            sb.append(separator);
339        }
340
341        return sb.toString();
342    }
343
344    public static void removeDir(File d) {
345        String[] list = d.list();
346        if (list == null) {
347            list = new String[0];
348        }
349        for (String s : list) {
350            File f = new File(d, s);
351            if (f.isDirectory()) {
352                removeDir(f);
353            } else {
354                delete(f);
355            }
356        }
357        delete(d);
358    }
359
360    private static void delete(File f) {
361        if (!f.delete()) {
362            if (isWindows()) {
363                System.gc();
364            }
365            try {
366                Thread.sleep(RETRY_SLEEP_MILLIS);
367            } catch (InterruptedException ex) {
368                // Ignore Exception
369            }
370            if (!f.delete()) {
371                f.deleteOnExit();
372            }
373        }
374    }
375
376    /**
377     * Renames a file.
378     *
379     * @param  from                      the from file
380     * @param  to                        the to file
381     * @param  copyAndDeleteOnRenameFail whether to fallback and do copy and delete, if renameTo fails
382     * @return                           <tt>true</tt> if the file was renamed, otherwise <tt>false</tt>
383     * @throws java.io.IOException       is thrown if error renaming file
384     */
385    public static boolean renameFile(File from, File to, boolean copyAndDeleteOnRenameFail) throws IOException {
386        // do not try to rename non existing files
387        if (!from.exists()) {
388            return false;
389        }
390
391        // some OS such as Windows can have problem doing rename IO operations so we may need to
392        // retry a couple of times to let it work
393        boolean renamed = false;
394        int count = 0;
395        while (!renamed && count < 3) {
396            if (LOG.isDebugEnabled() && count > 0) {
397                LOG.debug("Retrying attempt {} to rename file from: {} to: {}", count, from, to);
398            }
399
400            renamed = from.renameTo(to);
401            if (!renamed && count > 0) {
402                try {
403                    Thread.sleep(1000);
404                } catch (InterruptedException e) {
405                    // ignore
406                }
407            }
408            count++;
409        }
410
411        // we could not rename using renameTo, so lets fallback and do a copy/delete approach.
412        // for example if you move files between different file systems (linux -> windows etc.)
413        if (!renamed && copyAndDeleteOnRenameFail) {
414            // now do a copy and delete as all rename attempts failed
415            LOG.debug("Cannot rename file from: {} to: {}, will now use a copy/delete approach instead", from, to);
416            renamed = renameFileUsingCopy(from, to);
417        }
418
419        if (LOG.isDebugEnabled() && count > 0) {
420            LOG.debug("Tried {} to rename file: {} to: {} with result: {}", count, from, to, renamed);
421        }
422        return renamed;
423    }
424
425    /**
426     * Rename file using copy and delete strategy. This is primarily used in environments where the regular rename
427     * operation is unreliable.
428     * 
429     * @param  from        the file to be renamed
430     * @param  to          the new target file
431     * @return             <tt>true</tt> if the file was renamed successfully, otherwise <tt>false</tt>
432     * @throws IOException If an I/O error occurs during copy or delete operations.
433     */
434    public static boolean renameFileUsingCopy(File from, File to) throws IOException {
435        // do not try to rename non existing files
436        if (!from.exists()) {
437            return false;
438        }
439
440        LOG.debug("Rename file '{}' to '{}' using copy/delete strategy.", from, to);
441
442        copyFile(from, to);
443        if (!deleteFile(from)) {
444            throw new IOException(
445                    "Renaming file from '" + from + "' to '" + to + "' failed: Cannot delete file '" + from
446                                  + "' after copy succeeded");
447        }
448
449        return true;
450    }
451
452    /**
453     * Copies the file
454     *
455     * @param  from        the source file
456     * @param  to          the destination file
457     * @throws IOException If an I/O error occurs during copy operation
458     */
459    public static void copyFile(File from, File to) throws IOException {
460        Files.copy(from.toPath(), to.toPath(), StandardCopyOption.REPLACE_EXISTING);
461    }
462
463    /**
464     * Deletes the file.
465     * <p/>
466     * This implementation will attempt to delete the file up till three times with one second delay, which can mitigate
467     * problems on deleting files on some platforms such as Windows.
468     *
469     * @param file the file to delete
470     */
471    public static boolean deleteFile(File file) {
472        // do not try to delete non existing files
473        if (!file.exists()) {
474            return false;
475        }
476
477        // some OS such as Windows can have problem doing delete IO operations so we may need to
478        // retry a couple of times to let it work
479        boolean deleted = false;
480        int count = 0;
481        while (!deleted && count < 3) {
482            LOG.debug("Retrying attempt {} to delete file: {}", count, file);
483
484            deleted = file.delete();
485            if (!deleted && count > 0) {
486                try {
487                    Thread.sleep(1000);
488                } catch (InterruptedException e) {
489                    // ignore
490                }
491            }
492            count++;
493        }
494
495        if (LOG.isDebugEnabled() && count > 0) {
496            LOG.debug("Tried {} to delete file: {} with result: {}", count, file, deleted);
497        }
498        return deleted;
499    }
500
501    /**
502     * Is the given file an absolute file.
503     * <p/>
504     * Will also work around issue on Windows to consider files on Windows starting with a \ as absolute files. This
505     * makes the logic consistent across all OS platforms.
506     *
507     * @param  file the file
508     * @return      <tt>true</ff> if its an absolute path, <tt>false</tt> otherwise.
509     */
510    public static boolean isAbsolute(File file) {
511        if (isWindows()) {
512            // special for windows
513            String path = file.getPath();
514            if (path.startsWith(File.separator)) {
515                return true;
516            }
517        }
518        return file.isAbsolute();
519    }
520
521    /**
522     * Creates a new file.
523     *
524     * @param  file        the file
525     * @return             <tt>true</tt> if created a new file, <tt>false</tt> otherwise
526     * @throws IOException is thrown if error creating the new file
527     */
528    public static boolean createNewFile(File file) throws IOException {
529        // need to check first
530        if (file.exists()) {
531            return false;
532        }
533        try {
534            return file.createNewFile();
535        } catch (IOException e) {
536            // and check again if the file was created as createNewFile may create the file
537            // but throw a permission error afterwards when using some NAS
538            if (file.exists()) {
539                return true;
540            } else {
541                throw e;
542            }
543        }
544    }
545
546}