1 /*
2 * Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package java.util.logging;
27
28 import static java.nio.file.StandardOpenOption.APPEND;
29 import static java.nio.file.StandardOpenOption.CREATE_NEW;
30 import static java.nio.file.StandardOpenOption.WRITE;
31
32 import java.io.BufferedOutputStream;
33 import java.io.File;
34 import java.io.FileOutputStream;
35 import java.io.IOException;
36 import java.io.OutputStream;
37 import java.nio.channels.FileChannel;
38 import java.nio.channels.OverlappingFileLockException;
39 import java.nio.file.FileAlreadyExistsException;
40 import java.nio.file.Files;
41 import java.nio.file.LinkOption;
42 import java.nio.file.NoSuchFileException;
43 import java.nio.file.Path;
44 import java.nio.file.Paths;
45 import java.security.AccessController;
46 import java.security.PrivilegedAction;
47 import java.util.HashSet;
48 import java.util.Set;
49
50 /**
51 * Simple file logging <tt>Handler</tt>.
52 * <p>
53 * The <tt>FileHandler</tt> can either write to a specified file,
54 * or it can write to a rotating set of files.
55 * <p>
56 * For a rotating set of files, as each file reaches a given size
57 * limit, it is closed, rotated out, and a new file opened.
58 * Successively older files are named by adding "0", "1", "2",
59 * etc. into the base filename.
60 * <p>
61 * By default buffering is enabled in the IO libraries but each log
62 * record is flushed out when it is complete.
63 * <p>
64 * By default the <tt>XMLFormatter</tt> class is used for formatting.
65 * <p>
66 * <b>Configuration:</b>
67 * By default each <tt>FileHandler</tt> is initialized using the following
68 * <tt>LogManager</tt> configuration properties where <tt><handler-name></tt>
69 * refers to the fully-qualified class name of the handler.
70 * If properties are not defined
71 * (or have invalid values) then the specified default values are used.
72 * <ul>
73 * <li> <handler-name>.level
74 * specifies the default level for the <tt>Handler</tt>
75 * (defaults to <tt>Level.ALL</tt>). </li>
76 * <li> <handler-name>.filter
77 * specifies the name of a <tt>Filter</tt> class to use
78 * (defaults to no <tt>Filter</tt>). </li>
79 * <li> <handler-name>.formatter
80 * specifies the name of a <tt>Formatter</tt> class to use
81 * (defaults to <tt>java.util.logging.XMLFormatter</tt>) </li>
82 * <li> <handler-name>.encoding
83 * the name of the character set encoding to use (defaults to
84 * the default platform encoding). </li>
85 * <li> <handler-name>.limit
86 * specifies an approximate maximum amount to write (in bytes)
87 * to any one file. If this is zero, then there is no limit.
88 * (Defaults to no limit). </li>
89 * <li> <handler-name>.count
90 * specifies how many output files to cycle through (defaults to 1). </li>
91 * <li> <handler-name>.pattern
92 * specifies a pattern for generating the output file name. See
93 * below for details. (Defaults to "%h/java%u.log"). </li>
94 * <li> <handler-name>.append
95 * specifies whether the FileHandler should append onto
96 * any existing files (defaults to false). </li>
97 * </ul>
98 * <p>
99 * For example, the properties for {@code FileHandler} would be:
100 * <ul>
101 * <li> java.util.logging.FileHandler.level=INFO </li>
102 * <li> java.util.logging.FileHandler.formatter=java.util.logging.SimpleFormatter </li>
103 * </ul>
104 * <p>
105 * For a custom handler, e.g. com.foo.MyHandler, the properties would be:
106 * <ul>
107 * <li> com.foo.MyHandler.level=INFO </li>
108 * <li> com.foo.MyHandler.formatter=java.util.logging.SimpleFormatter </li>
109 * </ul>
110 * <p>
111 * A pattern consists of a string that includes the following special
112 * components that will be replaced at runtime:
113 * <ul>
114 * <li> "/" the local pathname separator </li>
115 * <li> "%t" the system temporary directory </li>
116 * <li> "%h" the value of the "user.home" system property </li>
117 * <li> "%g" the generation number to distinguish rotated logs </li>
118 * <li> "%u" a unique number to resolve conflicts </li>
119 * <li> "%%" translates to a single percent sign "%" </li>
120 * </ul>
121 * If no "%g" field has been specified and the file count is greater
122 * than one, then the generation number will be added to the end of
123 * the generated filename, after a dot.
124 * <p>
125 * Thus for example a pattern of "%t/java%g.log" with a count of 2
126 * would typically cause log files to be written on Solaris to
127 * /var/tmp/java0.log and /var/tmp/java1.log whereas on Windows 95 they
128 * would be typically written to C:\TEMP\java0.log and C:\TEMP\java1.log
129 * <p>
130 * Generation numbers follow the sequence 0, 1, 2, etc.
131 * <p>
132 * Normally the "%u" unique field is set to 0. However, if the <tt>FileHandler</tt>
133 * tries to open the filename and finds the file is currently in use by
134 * another process it will increment the unique number field and try
135 * again. This will be repeated until <tt>FileHandler</tt> finds a file name that
136 * is not currently in use. If there is a conflict and no "%u" field has
137 * been specified, it will be added at the end of the filename after a dot.
138 * (This will be after any automatically added generation number.)
139 * <p>
140 * Thus if three processes were all trying to log to fred%u.%g.txt then
141 * they might end up using fred0.0.txt, fred1.0.txt, fred2.0.txt as
142 * the first file in their rotating sequences.
143 * <p>
144 * Note that the use of unique ids to avoid conflicts is only guaranteed
145 * to work reliably when using a local disk file system.
146 *
147 * @since 1.4
148 */
149
150 public class FileHandler extends StreamHandler {
151 private MeteredStream meter;
152 private boolean append;
153 private int limit; // zero => no limit.
154 private int count;
155 private String pattern;
156 private String lockFileName;
157 private FileChannel lockFileChannel;
158 private File files[];
159 private static final int DEFAULT_MAX_LOCKS = 100;
160 private static int maxLocks;
161 private static final Set<String> locks = new HashSet<>();
162
163 /*
164 * Initialize maxLocks from the System property if set.
165 * If invalid/no property is provided 100 will be used as a default value.
166 */
167 static {
168 maxLocks = java.security.AccessController.doPrivileged(
169 (PrivilegedAction<Integer>) () ->
170 Integer.getInteger(
171 "jdk.internal.FileHandlerLogging.maxLocks",
172 DEFAULT_MAX_LOCKS)
173 );
174
175 if (maxLocks <= 0) {
176 maxLocks = DEFAULT_MAX_LOCKS;
177 }
178 }
179
180 /**
181 * A metered stream is a subclass of OutputStream that
182 * (a) forwards all its output to a target stream
183 * (b) keeps track of how many bytes have been written
184 */
185 private class MeteredStream extends OutputStream {
186 final OutputStream out;
187 int written;
188
189 MeteredStream(OutputStream out, int written) {
190 this.out = out;
191 this.written = written;
192 }
193
194 @Override
195 public void write(int b) throws IOException {
196 out.write(b);
197 written++;
198 }
199
200 @Override
201 public void write(byte buff[]) throws IOException {
202 out.write(buff);
203 written += buff.length;
204 }
205
206 @Override
207 public void write(byte buff[], int off, int len) throws IOException {
208 out.write(buff,off,len);
209 written += len;
210 }
211
212 @Override
213 public void flush() throws IOException {
214 out.flush();
215 }
216
217 @Override
218 public void close() throws IOException {
219 out.close();
220 }
221 }
222
223 private void open(File fname, boolean append) throws IOException {
224 int len = 0;
225 if (append) {
226 len = (int)fname.length();
227 }
228 FileOutputStream fout = new FileOutputStream(fname.toString(), append);
229 BufferedOutputStream bout = new BufferedOutputStream(fout);
230 meter = new MeteredStream(bout, len);
231 setOutputStream(meter);
232 }
233
234 /**
235 * Configure a FileHandler from LogManager properties and/or default values
236 * as specified in the class javadoc.
237 */
238 private void configure() {
239 LogManager manager = LogManager.getLogManager();
240
241 String cname = getClass().getName();
242
243 pattern = manager.getStringProperty(cname + ".pattern", "%h/java%u.log");
244 limit = manager.getIntProperty(cname + ".limit", 0);
245 if (limit < 0) {
246 limit = 0;
247 }
248 count = manager.getIntProperty(cname + ".count", 1);
249 if (count <= 0) {
250 count = 1;
251 }
252 append = manager.getBooleanProperty(cname + ".append", false);
253 setLevel(manager.getLevelProperty(cname + ".level", Level.ALL));
254 setFilter(manager.getFilterProperty(cname + ".filter", null));
255 setFormatter(manager.getFormatterProperty(cname + ".formatter", new XMLFormatter()));
256 try {
257 setEncoding(manager.getStringProperty(cname +".encoding", null));
258 } catch (Exception ex) {
259 try {
260 setEncoding(null);
261 } catch (Exception ex2) {
262 // doing a setEncoding with null should always work.
263 // assert false;
264 }
265 }
266 }
267
268
269 /**
270 * Construct a default <tt>FileHandler</tt>. This will be configured
271 * entirely from <tt>LogManager</tt> properties (or their default values).
272 * <p>
273 * @exception IOException if there are IO problems opening the files.
274 * @exception SecurityException if a security manager exists and if
275 * the caller does not have <tt>LoggingPermission("control"))</tt>.
276 * @exception NullPointerException if pattern property is an empty String.
277 */
278 public FileHandler() throws IOException, SecurityException {
279 checkPermission();
280 configure();
281 openFiles();
282 }
283
284 /**
285 * Initialize a <tt>FileHandler</tt> to write to the given filename.
286 * <p>
287 * The <tt>FileHandler</tt> is configured based on <tt>LogManager</tt>
288 * properties (or their default values) except that the given pattern
289 * argument is used as the filename pattern, the file limit is
290 * set to no limit, and the file count is set to one.
291 * <p>
292 * There is no limit on the amount of data that may be written,
293 * so use this with care.
294 *
295 * @param pattern the name of the output file
296 * @exception IOException if there are IO problems opening the files.
297 * @exception SecurityException if a security manager exists and if
298 * the caller does not have <tt>LoggingPermission("control")</tt>.
299 * @exception IllegalArgumentException if pattern is an empty string
300 */
301 public FileHandler(String pattern) throws IOException, SecurityException {
302 if (pattern.length() < 1 ) {
303 throw new IllegalArgumentException();
304 }
305 checkPermission();
306 configure();
307 this.pattern = pattern;
308 this.limit = 0;
309 this.count = 1;
310 openFiles();
311 }
312
313 /**
314 * Initialize a <tt>FileHandler</tt> to write to the given filename,
315 * with optional append.
316 * <p>
317 * The <tt>FileHandler</tt> is configured based on <tt>LogManager</tt>
318 * properties (or their default values) except that the given pattern
319 * argument is used as the filename pattern, the file limit is
320 * set to no limit, the file count is set to one, and the append
321 * mode is set to the given <tt>append</tt> argument.
322 * <p>
323 * There is no limit on the amount of data that may be written,
324 * so use this with care.
325 *
326 * @param pattern the name of the output file
327 * @param append specifies append mode
328 * @exception IOException if there are IO problems opening the files.
329 * @exception SecurityException if a security manager exists and if
330 * the caller does not have <tt>LoggingPermission("control")</tt>.
331 * @exception IllegalArgumentException if pattern is an empty string
332 */
333 public FileHandler(String pattern, boolean append) throws IOException,
334 SecurityException {
335 if (pattern.length() < 1 ) {
336 throw new IllegalArgumentException();
337 }
338 checkPermission();
339 configure();
340 this.pattern = pattern;
341 this.limit = 0;
342 this.count = 1;
343 this.append = append;
344 openFiles();
345 }
346
347 /**
348 * Initialize a <tt>FileHandler</tt> to write to a set of files. When
349 * (approximately) the given limit has been written to one file,
350 * another file will be opened. The output will cycle through a set
351 * of count files.
352 * <p>
353 * The <tt>FileHandler</tt> is configured based on <tt>LogManager</tt>
354 * properties (or their default values) except that the given pattern
355 * argument is used as the filename pattern, the file limit is
356 * set to the limit argument, and the file count is set to the
357 * given count argument.
358 * <p>
359 * The count must be at least 1.
360 *
361 * @param pattern the pattern for naming the output file
362 * @param limit the maximum number of bytes to write to any one file
363 * @param count the number of files to use
364 * @exception IOException if there are IO problems opening the files.
365 * @exception SecurityException if a security manager exists and if
366 * the caller does not have <tt>LoggingPermission("control")</tt>.
367 * @exception IllegalArgumentException if {@code limit < 0}, or {@code count < 1}.
368 * @exception IllegalArgumentException if pattern is an empty string
369 */
370 public FileHandler(String pattern, int limit, int count)
371 throws IOException, SecurityException {
372 if (limit < 0 || count < 1 || pattern.length() < 1) {
373 throw new IllegalArgumentException();
374 }
375 checkPermission();
376 configure();
377 this.pattern = pattern;
378 this.limit = limit;
379 this.count = count;
380 openFiles();
381 }
382
383 /**
384 * Initialize a <tt>FileHandler</tt> to write to a set of files
385 * with optional append. When (approximately) the given limit has
386 * been written to one file, another file will be opened. The
387 * output will cycle through a set of count files.
388 * <p>
389 * The <tt>FileHandler</tt> is configured based on <tt>LogManager</tt>
390 * properties (or their default values) except that the given pattern
391 * argument is used as the filename pattern, the file limit is
392 * set to the limit argument, and the file count is set to the
393 * given count argument, and the append mode is set to the given
394 * <tt>append</tt> argument.
395 * <p>
396 * The count must be at least 1.
397 *
398 * @param pattern the pattern for naming the output file
399 * @param limit the maximum number of bytes to write to any one file
400 * @param count the number of files to use
401 * @param append specifies append mode
402 * @exception IOException if there are IO problems opening the files.
403 * @exception SecurityException if a security manager exists and if
404 * the caller does not have <tt>LoggingPermission("control")</tt>.
405 * @exception IllegalArgumentException if {@code limit < 0}, or {@code count < 1}.
406 * @exception IllegalArgumentException if pattern is an empty string
407 *
408 */
409 public FileHandler(String pattern, int limit, int count, boolean append)
410 throws IOException, SecurityException {
411 if (limit < 0 || count < 1 || pattern.length() < 1) {
412 throw new IllegalArgumentException();
413 }
414 checkPermission();
415 configure();
416 this.pattern = pattern;
417 this.limit = limit;
418 this.count = count;
419 this.append = append;
420 openFiles();
421 }
422
423 private boolean isParentWritable(Path path) {
424 Path parent = path.getParent();
425 if (parent == null) {
426 parent = path.toAbsolutePath().getParent();
427 }
428 return parent != null && Files.isWritable(parent);
429 }
430
431 /**
432 * Open the set of output files, based on the configured
433 * instance variables.
434 */
435 private void openFiles() throws IOException {
436 LogManager manager = LogManager.getLogManager();
437 manager.checkPermission();
438 if (count < 1) {
439 throw new IllegalArgumentException("file count = " + count);
440 }
441 if (limit < 0) {
442 limit = 0;
443 }
444
445 // We register our own ErrorManager during initialization
446 // so we can record exceptions.
447 InitializationErrorManager em = new InitializationErrorManager();
448 setErrorManager(em);
449
450 // Create a lock file. This grants us exclusive access
451 // to our set of output files, as long as we are alive.
452 int unique = -1;
453 for (;;) {
454 unique++;
455 if (unique > maxLocks) {
456 throw new IOException("Couldn't get lock for " + pattern
457 + ", maxLocks: " + maxLocks);
458 }
459 // Generate a lock file name from the "unique" int.
460 lockFileName = generate(pattern, 0, unique).toString() + ".lck";
461 // Now try to lock that filename.
462 // Because some systems (e.g., Solaris) can only do file locks
463 // between processes (and not within a process), we first check
464 // if we ourself already have the file locked.
465 synchronized(locks) {
466 if (locks.contains(lockFileName)) {
467 // We already own this lock, for a different FileHandler
468 // object. Try again.
469 continue;
470 }
471
472 final Path lockFilePath = Paths.get(lockFileName);
473 FileChannel channel = null;
474 int retries = -1;
475 boolean fileCreated = false;
476 while (channel == null && retries++ < 1) {
477 try {
478 channel = FileChannel.open(lockFilePath,
479 CREATE_NEW, WRITE);
480 fileCreated = true;
481 } catch (FileAlreadyExistsException ix) {
482 // This may be a zombie file left over by a previous
483 // execution. Reuse it - but only if we can actually
484 // write to its directory.
485 // Note that this is a situation that may happen,
486 // but not too frequently.
487 if (Files.isRegularFile(lockFilePath, LinkOption.NOFOLLOW_LINKS)
488 && isParentWritable(lockFilePath)) {
489 try {
490 channel = FileChannel.open(lockFilePath,
491 WRITE, APPEND);
492 } catch (NoSuchFileException x) {
493 // Race condition - retry once, and if that
494 // fails again just try the next name in
495 // the sequence.
496 continue;
497 } catch(IOException x) {
498 // the file may not be writable for us.
499 // try the next name in the sequence
500 break;
501 }
502 } else {
503 // at this point channel should still be null.
504 // break and try the next name in the sequence.
505 break;
506 }
507 }
508 }
509
510 if (channel == null) continue; // try the next name;
511 lockFileChannel = channel;
512
513 boolean available;
514 try {
515 available = lockFileChannel.tryLock() != null;
516 // We got the lock OK.
517 // At this point we could call File.deleteOnExit().
518 // However, this could have undesirable side effects
519 // as indicated by JDK-4872014. So we will instead
520 // rely on the fact that close() will remove the lock
521 // file and that whoever is creating FileHandlers should
522 // be responsible for closing them.
523 } catch (IOException ix) {
524 // We got an IOException while trying to get the lock.
525 // This normally indicates that locking is not supported
526 // on the target directory. We have to proceed without
527 // getting a lock. Drop through, but only if we did
528 // create the file...
529 available = fileCreated;
530 } catch (OverlappingFileLockException x) {
531 // someone already locked this file in this VM, through
532 // some other channel - that is - using something else
533 // than new FileHandler(...);
534 // continue searching for an available lock.
535 available = false;
536 }
537 if (available) {
538 // We got the lock. Remember it.
539 locks.add(lockFileName);
540 break;
541 }
542
543 // We failed to get the lock. Try next file.
544 lockFileChannel.close();
545 }
546 }
547
548 files = new File[count];
549 for (int i = 0; i < count; i++) {
550 files[i] = generate(pattern, i, unique);
551 }
552
553 // Create the initial log file.
554 if (append) {
555 open(files[0], true);
556 } else {
557 rotate();
558 }
559
560 // Did we detect any exceptions during initialization?
561 Exception ex = em.lastException;
562 if (ex != null) {
563 if (ex instanceof IOException) {
564 throw (IOException) ex;
565 } else if (ex instanceof SecurityException) {
566 throw (SecurityException) ex;
567 } else {
568 throw new IOException("Exception: " + ex);
569 }
570 }
571
572 // Install the normal default ErrorManager.
573 setErrorManager(new ErrorManager());
574 }
575
576 /**
577 * Generate a file based on a user-supplied pattern, generation number,
578 * and an integer uniqueness suffix
579 * @param pattern the pattern for naming the output file
580 * @param generation the generation number to distinguish rotated logs
581 * @param unique a unique number to resolve conflicts
582 * @return the generated File
583 * @throws IOException
584 */
585 private File generate(String pattern, int generation, int unique)
586 throws IOException {
587 File file = null;
588 String word = "";
589 int ix = 0;
590 boolean sawg = false;
591 boolean sawu = false;
592 while (ix < pattern.length()) {
593 char ch = pattern.charAt(ix);
594 ix++;
595 char ch2 = 0;
596 if (ix < pattern.length()) {
597 ch2 = Character.toLowerCase(pattern.charAt(ix));
598 }
599 if (ch == '/') {
600 if (file == null) {
601 file = new File(word);
602 } else {
603 file = new File(file, word);
604 }
605 word = "";
606 continue;
607 } else if (ch == '%') {
608 if (ch2 == 't') {
609 String tmpDir = System.getProperty("java.io.tmpdir");
610 if (tmpDir == null) {
611 tmpDir = System.getProperty("user.home");
612 }
613 file = new File(tmpDir);
614 ix++;
615 word = "";
616 continue;
617 } else if (ch2 == 'h') {
618 file = new File(System.getProperty("user.home"));
619 if (isSetUID()) {
620 // Ok, we are in a set UID program. For safety's sake
621 // we disallow attempts to open files relative to %h.
622 throw new IOException("can't use %h in set UID program");
623 }
624 ix++;
625 word = "";
626 continue;
627 } else if (ch2 == 'g') {
628 word = word + generation;
629 sawg = true;
630 ix++;
631 continue;
632 } else if (ch2 == 'u') {
633 word = word + unique;
634 sawu = true;
635 ix++;
636 continue;
637 } else if (ch2 == '%') {
638 word = word + "%";
639 ix++;
640 continue;
641 }
642 }
643 word = word + ch;
644 }
645 if (count > 1 && !sawg) {
646 word = word + "." + generation;
647 }
648 if (unique > 0 && !sawu) {
649 word = word + "." + unique;
650 }
651 if (word.length() > 0) {
652 if (file == null) {
653 file = new File(word);
654 } else {
655 file = new File(file, word);
656 }
657 }
658 return file;
659 }
660
661 /**
662 * Rotate the set of output files
663 */
664 private synchronized void rotate() {
665 Level oldLevel = getLevel();
666 setLevel(Level.OFF);
667
668 super.close();
669 for (int i = count-2; i >= 0; i--) {
670 File f1 = files[i];
671 File f2 = files[i+1];
672 if (f1.exists()) {
673 if (f2.exists()) {
674 f2.delete();
675 }
676 f1.renameTo(f2);
677 }
678 }
679 try {
680 open(files[0], false);
681 } catch (IOException ix) {
682 // We don't want to throw an exception here, but we
683 // report the exception to any registered ErrorManager.
684 reportError(null, ix, ErrorManager.OPEN_FAILURE);
685
686 }
687 setLevel(oldLevel);
688 }
689
690 /**
691 * Format and publish a <tt>LogRecord</tt>.
692 *
693 * @param record description of the log event. A null record is
694 * silently ignored and is not published
695 */
696 @Override
697 public synchronized void publish(LogRecord record) {
698 if (!isLoggable(record)) {
699 return;
700 }
701 super.publish(record);
702 flush();
703 if (limit > 0 && meter.written >= limit) {
704 // We performed access checks in the "init" method to make sure
705 // we are only initialized from trusted code. So we assume
706 // it is OK to write the target files, even if we are
707 // currently being called from untrusted code.
708 // So it is safe to raise privilege here.
709 AccessController.doPrivileged(new PrivilegedAction<Object>() {
710 @Override
711 public Object run() {
712 rotate();
713 return null;
714 }
715 });
716 }
717 }
718
719 /**
720 * Close all the files.
721 *
722 * @exception SecurityException if a security manager exists and if
723 * the caller does not have <tt>LoggingPermission("control")</tt>.
724 */
725 @Override
726 public synchronized void close() throws SecurityException {
727 super.close();
728 // Unlock any lock file.
729 if (lockFileName == null) {
730 return;
731 }
732 try {
733 // Close the lock file channel (which also will free any locks)
734 lockFileChannel.close();
735 } catch (Exception ex) {
736 // Problems closing the stream. Punt.
737 }
738 synchronized(locks) {
739 locks.remove(lockFileName);
740 }
741 new File(lockFileName).delete();
742 lockFileName = null;
743 lockFileChannel = null;
744 }
745
746 private static class InitializationErrorManager extends ErrorManager {
747 Exception lastException;
748 @Override
749 public void error(String msg, Exception ex, int code) {
750 lastException = ex;
751 }
752 }
753
754 /**
755 * check if we are in a set UID program.
756 */
757 private static native boolean isSetUID();
758 }