Examples with FileChannel java.nio.channels.FileChannel used on opensource projects

Example 66 with FileChannel

use of java.nio.channels.FileChannel in project RxDownload by ssseasonnn.

the class FileHelper method fileNotComplete.

public boolean fileNotComplete(File tempFile) throws IOException {
    RandomAccessFile record = null;
    FileChannel channel = null;
    try {
        record = new RandomAccessFile(tempFile, ACCESS);
        channel = record.getChannel();
        MappedByteBuffer buffer = channel.map(READ_WRITE, 0, RECORD_FILE_TOTAL_SIZE);
        long startByte;
        long endByte;
        for (int i = 0; i < maxThreads; i++) {
            startByte = buffer.getLong();
            endByte = buffer.getLong();
            if (startByte <= endByte) {
                return true;
            }
        }
        return false;
    } finally {
        closeQuietly(channel);
        closeQuietly(record);
    }
}

Example 67 with FileChannel

use of java.nio.channels.FileChannel in project CoreNLP by stanfordnlp.

the class FileBackedCache method acquireFileLock.

@SuppressWarnings("SynchronizationOnLocalVariableOrMethodParameter")
protected FileSemaphore acquireFileLock(File f) throws IOException {
    assert canonicalFile.intern(f.getCanonicalFile()) == f;
    synchronized (f) {
        // Check semaphore
        synchronized (fileLocks) {
            if (fileLocks.containsKey(f)) {
                FileSemaphore sem = fileLocks.get(f);
                if (sem.isActive()) {
                    sem.take();
                    return sem;
                } else {
                    fileLocks.remove(f);
                }
            }
        }
        // Get the channel
        FileChannel channel = new RandomAccessFile(f, "rw").getChannel();
        FileLock lockOrNull = null;
        // Try the lock
        for (int i = 0; i < 1000; ++i) {
            lockOrNull = channel.tryLock();
            if (lockOrNull == null || !lockOrNull.isValid()) {
                try {
                    Thread.sleep(1000);
                } catch (InterruptedException e) {
                    log(e);
                    throw new RuntimeInterruptedException(e);
                }
                if (i % 60 == 59) {
                    warn("FileBackedCache", "Lock still busy after " + ((i + 1) / 60) + " minutes");
                }
                //noinspection UnnecessaryContinue
                continue;
            } else {
                break;
            }
        }
        if (lockOrNull == null) {
            warn("FileBackedCache", "Could not acquire file lock! Continuing without lock");
        }
        // Return
        FileSemaphore sem = new FileSemaphore(lockOrNull, channel);
        synchronized (fileLocks) {
            fileLocks.put(f, sem);
        }
        return sem;
    }
}

Example 68 with FileChannel

use of java.nio.channels.FileChannel in project android-common by litesuits.

the class FileUtil method fileChannelCopy.

public static void fileChannelCopy(File s, File t) {
    FileInputStream fi = null;
    FileOutputStream fo = null;
    try {
        fi = new FileInputStream(s);
        fo = new FileOutputStream(t);
        //得到对应的文件通道
        FileChannel in = fi.getChannel();
        //得到对应的文件通道
        FileChannel out = fo.getChannel();
        //连接两个通道，并且从in通道读取，然后写入out通道
        in.transferTo(0, in.size(), out);
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        try {
            if (fo != null)
                fo.close();
            if (fi != null)
                fi.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Example 69 with FileChannel

use of java.nio.channels.FileChannel in project min by macournoyer.

the class File method read.

// Taken from http://stackoverflow.com/questions/326390/how-to-create-a-java-string-from-the-contents-of-a-file
public static String read(String path) throws MinException {
    try {
        FileInputStream stream = new FileInputStream(new java.io.File(path));
        try {
            FileChannel fc = stream.getChannel();
            MappedByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, fc.size());
            /* Instead of using default, pass in a decoder. */
            return java.nio.charset.Charset.defaultCharset().decode(bb).toString();
        } finally {
            stream.close();
        }
    } catch (IOException e) {
        throw new MinException(e);
    }
}

Example 70 with FileChannel

use of java.nio.channels.FileChannel in project tape by square.

the class QueueFile method expandIfNecessary.

/**
   * If necessary, expands the file to accommodate an additional element of the given length.
   *
   * @param dataLength length of data being added
   */
private void expandIfNecessary(long dataLength) throws IOException {
    long elementLength = Element.HEADER_LENGTH + dataLength;
    long remainingBytes = remainingBytes();
    if (remainingBytes >= elementLength)
        return;
    // Expand.
    long previousLength = fileLength;
    long newLength;
    // Double the length until we can fit the new data.
    do {
        remainingBytes += previousLength;
        newLength = previousLength << 1;
        previousLength = newLength;
    } while (remainingBytes < elementLength);
    setLength(newLength);
    // Calculate the position of the tail end of the data in the ring buffer
    long endOfLastElement = wrapPosition(last.position + Element.HEADER_LENGTH + last.length);
    long count = 0;
    // If the buffer is split, we need to make it contiguous
    if (endOfLastElement <= first.position) {
        FileChannel channel = raf.getChannel();
        // destination position
        channel.position(fileLength);
        count = endOfLastElement - headerLength;
        if (channel.transferTo(headerLength, count, channel) != count) {
            throw new AssertionError("Copied insufficient number of bytes!");
        }
    }
    // Commit the expansion.
    if (last.position < first.position) {
        long newLastPosition = fileLength + last.position - headerLength;
        writeHeader(newLength, elementCount, first.position, newLastPosition);
        last = new Element(newLastPosition, last.length);
    } else {
        writeHeader(newLength, elementCount, first.position, last.position);
    }
    fileLength = newLength;
    if (zero) {
        ringErase(headerLength, count);
    }
}