Example usage for java.nio.channels FileLock release

List of usage examples for java.nio.channels FileLock release

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Introduction

In this page you can find the example usage for java.nio.channels FileLock release.

Prototype

public abstract void release() throws IOException;

Source Link

Document

Releases this lock.

Usage

From source file:com.asakusafw.runtime.util.lock.LocalFileLockProvider.java

@Override
public LocalFileLockObject<T> tryLock(T target) throws IOException {
    if (baseDirectory.mkdirs() == false && baseDirectory.isDirectory() == false) {
        throw new IOException(MessageFormat.format("Failed to create lock directory: {0}", baseDirectory));
    }//from   w  ww.  j a v a2 s .  co  m
    String fileName = String.format("%08x.lck", target == null ? -1 : target.hashCode()); //$NON-NLS-1$
    File lockFile = new File(baseDirectory, fileName);
    RandomAccessFile fd = new RandomAccessFile(lockFile, "rw"); //$NON-NLS-1$
    boolean success = false;
    try {
        if (LOG.isDebugEnabled()) {
            LOG.debug(MessageFormat.format("Start to acquire lock for \"{0}\" ({1})", //$NON-NLS-1$
                    target, lockFile));
        }
        FileLock lockEntity = getLock(target, lockFile, fd);
        if (lockEntity == null) {
            return null;
        } else {
            if (LOG.isDebugEnabled()) {
                LOG.debug(MessageFormat.format("Finished to acquire lock for \"{0}\" ({1})", //$NON-NLS-1$
                        target, lockFile));
            }
            try {
                fd.seek(0L);
                fd.setLength(0L);
                fd.write(String.valueOf(target).getBytes(ENCODING));
                success = true;
                return new LocalFileLockObject<>(target, lockFile, fd, lockEntity);
            } finally {
                if (success == false) {
                    lockEntity.release();
                }
            }
        }
    } finally {
        if (success == false) {
            fd.close();
        }
    }
}

From source file:com.espirit.moddev.examples.uxbridge.newsdrilldown.jpa.NewsHandler.java

/**
 * Deletes a newsdrilldown from the db.//from w  w  w  . j a  v  a2s  .  c  o  m
 *
 * @param entity The newsdrilldown to delete
 */
public void delete(UXBEntity entity) throws Exception {

    EntityManager em = null;
    EntityTransaction tx = null;
    try {

        em = emf.createEntityManager();
        tx = em.getTransaction();
        tx.begin();

        Query query = em.createQuery(new StringBuilder()
                .append("FROM news x WHERE x.fs_id = :fs_id AND x.language = :language").toString());
        query.setParameter("fs_id", Long.parseLong(entity.getUuid()));
        query.setParameter("language", entity.getLanguage());

        if (!query.getResultList().isEmpty()) {
            News art = (News) query.getSingleResult();
            // delete file from filesystem
            URL url = new URL(art.getUrl());
            File file = new File(webpath + url.getPath());
            if (file.exists()) {
                // Try acquiring the lock without blocking. This method returns
                // null or throws an exception if the file is already locked.
                try {
                    FileChannel channel = new RandomAccessFile(file, "rw").getChannel();
                    // Try to lock the file
                    FileLock lock = channel.tryLock();
                    // Delete the file
                    file.delete();
                    // Release the lock
                    lock.release();
                    lock.channel().close();
                } catch (OverlappingFileLockException e) {
                    logger.info("File is already locked in this thread or virtual machine");
                } catch (MalformedURLException e) {
                    logger.info("wrong url", e);
                }
            }
            // remove article from content repository

            em.remove(art);
        }
        tx.commit();
    } catch (Exception e) {
        if (tx != null) {
            tx.setRollbackOnly();
        }
        throw e;
    } finally {
        if (tx != null && tx.isActive()) {
            if (tx.getRollbackOnly()) {
                tx.rollback();
            }
        }
        if (em != null) {
            em.close();
        }
    }
}

From source file:ca.uviccscu.lp.server.main.ShutdownListener.java

@Deprecated
public void releaseLocks() {
    l.trace("Trying to check file locks ");
    try {//  w ww .j a  v a  2s  .  c om
        Collection c = FileUtils.listFiles(new File(Shared.workingDirectory), null, true);
        Object[] arr = c.toArray();
        for (int i = 0; i < arr.length; i++) {
            l.trace("Trying lock for: " + ((File) arr[i]).getAbsolutePath());
            // Get a file channel for the file
            File file = ((File) arr[i]);
            FileChannel channel = new RandomAccessFile(file, "rw").getChannel();
            // Use the file channel to create a lock on the file.
            // This method blocks until it can retrieve the lock.
            //FileLock lock = channel.lock();
            // Try acquiring the lock without blocking. This method returns
            // null or throws an exception if the file is already locked.
            FileLock lock = null;
            try {
                lock = channel.lock();
            } catch (OverlappingFileLockException ex) {
                l.trace("Lock already exists", ex);
            }
            if (lock == null) {
                l.trace("Lock failed - someone else holds lock");
            } else {
                l.trace("Lock shared: " + lock.isShared() + " Lock valid: " + lock.isValid());
                lock.release();
                l.trace("Lock release OK");
                try {
                    if (!file.delete()) {
                        throw new IOException();
                    }
                } catch (Exception e) {
                    l.trace("Delete failed", e);
                }
            }
        }
        //Thread.sleep(25000);

    } catch (Exception e) {
        // File is already locked in this thread or virtual machine
        l.trace("File lock problem", e);
    }
}

From source file:com.linuxbox.enkive.archiver.AbstractMessageArchivingService.java

private String saveToDisk(String messageData, String fileName)
        throws FailedToEmergencySaveException, SaveFileAlreadyExistsException {
    File emergencySaveFile = null;
    String emergencySaveFilePath = "UNKNOWN";
    BufferedWriter out = null;/*ww w  .j  a v  a 2  s .  c  o m*/
    FileOutputStream fileStream = null;
    try {
        emergencySaveFile = new File(getEmergencySaveRoot(), fileName);
        emergencySaveFilePath = emergencySaveFile.getCanonicalPath();
        fileStream = new FileOutputStream(emergencySaveFile);
        FileLock lock = null;
        try {
            lock = fileStream.getChannel().tryLock();
            if (lock == null) {
                throw new SaveFileAlreadyExistsException(emergencySaveFilePath);
            }

            out = new BufferedWriter(new OutputStreamWriter(fileStream));
            out.write(messageData);

            if (LOGGER.isInfoEnabled()) {
                LOGGER.info("Saved message to file: \"" + emergencySaveFilePath + "\"");
            }

            return emergencySaveFilePath;
        } finally {
            if (lock != null) {
                lock.release();
            }
        }
    } catch (IOException e) {
        LOGGER.fatal("Emergency save to disk failed. ", e);
        throw new FailedToEmergencySaveException(e);
    } finally {
        try {
            if (out != null) {
                out.close();
            } else if (fileStream != null) {
                fileStream.close();
            }
        } catch (IOException e) {
            if (LOGGER.isWarnEnabled()) {
                LOGGER.warn("Could not close emergency save file \"" + emergencySavePath + "\".");
            }
        }
    }
}

From source file:com.att.api.oauth.OAuthToken.java

/**
 * Attempts to load an OAuthToken from a file in an asynchronous-safe
 * manner./*from www  . ja  v  a  2  s  . c  o  m*/
 *
 * <p>
 * If <code>fpath</code> does not exist or some required values are missing
 * from the saved file, null is returned.
 * </p>
 *
 * <p>
 * <strong>WARNING</strong>: Because caching may be used, manually modifying
 * the saved token properties file may yield unexpected results unless
 * caching is disabled.
 * </p>
 *
 * @param fpath file path from which to load token
 * @return OAuthToken an OAuthToken object if successful, null otherwise
 * @throws IOException if there was an error loading the token
 * @see #useTokenCaching(boolean)
 */
public static OAuthToken loadToken(String fpath) throws IOException {
    FileInputStream fInputStream = null;
    FileLock fLock = null;

    synchronized (LOCK_OBJECT) {
        // attempt to load from cached tokens, thereby saving file I/O
        if (cachedTokens != null && cachedTokens.get(fpath) != null) {
            return cachedTokens.get(fpath);
        }

        if (!new File(fpath).exists()) {
            return null;
        }

        try {
            fInputStream = new FileInputStream(fpath);
            // acquire shared lock
            fLock = fInputStream.getChannel().lock(0L, Long.MAX_VALUE, true);
            Properties props = new Properties();
            props.load(fInputStream);
            if (!props.containsKey("creationTime") || !props.containsKey("expiresIn")) {
                return null;
            }

            String accessToken = props.getProperty("accessToken");
            if (accessToken == null || accessToken.equals("")) {
                return null;
            }

            String refreshToken = props.getProperty("refreshToken");

            String sExpiresIn = props.getProperty("expiresIn");
            long expiresIn = new Long(sExpiresIn).longValue();

            String sCreationTime = props.getProperty("creationTime");
            long creationTime = new Long(sCreationTime).longValue();

            return new OAuthToken(accessToken, expiresIn, refreshToken, creationTime);
        } catch (IOException e) {
            throw e; // pass along exception
        } finally {
            if (fLock != null) {
                fLock.release();
            }
            if (fInputStream != null) {
                fInputStream.close();
            }
        }
    }
}

From source file:org.spf4j.perf.tsdb.TimeSeriesDatabase.java

public void reReadTableInfos() throws IOException {
    synchronized (path) {
        FileLock lock = ch.lock(0, Long.MAX_VALUE, true);
        try {//  w ww .  j a  v  a  2 s  . co m
            toc = new TableOfContents(file, toc.getLocation()); // reread toc
            readTableInfos();
        } catch (IOException | RuntimeException e) {
            try {
                lock.release();
                throw e;
            } catch (IOException ex) {
                ex.addSuppressed(e);
                throw ex;
            }
        }
        lock.release();
    }
}

From source file:org.apache.axiom.attachments.impl.BufferUtils.java

/**
 * Opimized writing to FileOutputStream using a channel
 * @param is//  w  ww.j av a  2 s.  c o m
 * @param fos
 * @return false if lock was not aquired
 * @throws IOException
 */
public static boolean inputStream2FileOutputStream(InputStream is, FileOutputStream fos) throws IOException {

    // See if a file channel and lock can be obtained on the FileOutputStream
    FileChannel channel = null;
    FileLock lock = null;
    ByteBuffer bb = null;
    try {
        channel = fos.getChannel();
        if (channel != null) {
            lock = channel.tryLock();
        }
        bb = getTempByteBuffer();
    } catch (Throwable t) {
    }
    if (lock == null || bb == null || !bb.hasArray()) {
        releaseTempByteBuffer(bb);
        return false; // lock could not be set or bb does not have direct array access
    }

    try {

        // Read directly into the ByteBuffer array
        int bytesRead = is.read(bb.array());
        // Continue reading until no bytes are read and no
        // bytes are now available.
        while (bytesRead > 0 || is.available() > 0) {
            if (bytesRead > 0) {
                int written = 0;

                if (bytesRead < BUFFER_LEN) {
                    // If the ByteBuffer is not full, allocate a new one
                    ByteBuffer temp = ByteBuffer.allocate(bytesRead);
                    temp.put(bb.array(), 0, bytesRead);
                    temp.position(0);
                    written = channel.write(temp);
                } else {
                    // Write to channel
                    bb.position(0);
                    written = channel.write(bb);
                    bb.clear();
                }

            }

            // REVIEW: Do we need to ensure that bytesWritten is 
            // the same as the number of bytes sent ?

            bytesRead = is.read(bb.array());
        }
    } finally {
        // Release the lock
        lock.release();
        releaseTempByteBuffer(bb);
    }
    return true;
}

From source file:org.apache.hadoop.dfs.StorageInfo.java

/**
 * Check whether underlying file system supports file locking.
 * //from w ww . ja v a2  s.com
 * @return <code>true</code> if exclusive locks are supported or
 *         <code>false</code> otherwise.
 * @throws IOException
 * @see StorageDirectory#lock()
 */
boolean isLockSupported(int idx) throws IOException {
    StorageDirectory sd = storageDirs.get(idx);
    FileLock firstLock = null;
    FileLock secondLock = null;
    try {
        firstLock = sd.lock;
        if (firstLock == null) {
            firstLock = sd.tryLock();
            if (firstLock == null)
                return true;
        }
        secondLock = sd.tryLock();
        if (secondLock == null)
            return true;
    } finally {
        if (firstLock != null && firstLock != sd.lock) {
            firstLock.release();
            firstLock.channel().close();
        }
        if (secondLock != null) {
            secondLock.release();
            secondLock.channel().close();
        }
    }
    return false;
}

From source file:org.fuin.utils4j.Utils4JTest.java

/**
 * Create a runnable that locks the file.
 * //  w  ww .  j  av a  2  s  .c  o  m
 * @param file
 *            File to lock.
 * @param ec
 *            If an exception occurs it will stored in this object.
 * @param tryLockMax
 *            Number of tries to lock before throwing an exception.
 * @param tryWaitMillis
 *            Milliseconds to sleep between retries.
 * @param sleepMillis
 *            Number of milliseconds to hold the lock.
 * 
 * @return New runnable instance.
 */
private Runnable createLockRunnable(final File file, final ExceptionContainer ec, final int tryLockMax,
        final long tryWaitMillis, final long sleepMillis) {
    return new Runnable() {
        public void run() {
            try {
                final RandomAccessFile raf = new RandomAccessFile(file, "rw");
                try {
                    final FileLock lock = Utils4J.lockRandomAccessFile(raf, tryLockMax, tryWaitMillis);
                    try {
                        // Hold the lock for one second
                        Thread.sleep(sleepMillis);
                    } finally {
                        lock.release();
                    }
                } finally {
                    raf.close();
                }
            } catch (final Exception ex) {
                ec.exception = ex;
            }
        }
    };
}

From source file:org.apache.flume.channel.file.Log.java

/**
 * Unlock directory.//from  w  ww.ja  va  2 s.c om
 *
 * @throws IOException
 */
private void unlock(File dir) throws IOException {
    FileLock lock = locks.remove(dir.getAbsolutePath());
    if (lock == null) {
        return;
    }
    lock.release();
    lock.channel().close();
    lock = null;
}