Example usage for java.nio.channels FileChannel write

Introduction

In this page you can find the example usage for java.nio.channels FileChannel write.

Prototype

public final long write(ByteBuffer[] srcs) throws IOException 

Source Link

Document

Writes a sequence of bytes to this channel from the given buffers.

Usage

From source file:org.commoncrawl.util.S3Downloader.java

public static void main(String[] args) {

    boolean isRequesterPays = args[3].equals("1");
    S3Downloader downloader = new S3Downloader(args[0], args[1], args[2], isRequesterPays);
    String itemToFetch = args[4];

    try {//from   w w  w  . j  ava  2s  . co m

        downloader.initialize(new Callback() {

            Map<String, FileChannel> channelMap = new HashMap<String, FileChannel>();

            public boolean contentAvailable(int itemId, String itemKey, NIOBufferList contentBuffer) {
                LOG.info("Key:" + itemKey + " GOT:" + contentBuffer.available() + " Bytes");

                FileChannel channel = channelMap.get(itemKey);
                if (channel != null) {
                    try {
                        while (contentBuffer.available() != 0) {
                            ByteBuffer buffer = contentBuffer.read();
                            channel.write(buffer);
                        }
                        return true;
                    } catch (IOException e) {
                        LOG.error(StringUtils.stringifyException(e));
                        return false;
                    }
                }
                return false;
            }

            public void downloadComplete(int itemId, String itemKey) {
                LOG.info("Key:" + itemKey + " DownloadComplete");
                FileChannel channel = channelMap.get(itemKey);
                if (channel != null) {
                    try {
                        channel.close();
                    } catch (IOException e) {
                        LOG.error(StringUtils.stringifyException(e));
                    }
                }
                channelMap.remove(itemKey);
            }

            public void downloadFailed(int itemId, String itemKey, String errorCode) {
                LOG.info("Key:" + itemKey + " DownloadFailed. ErrorCode:" + errorCode);
                FileChannel channel = channelMap.get(itemKey);
                if (channel != null) {
                    try {
                        channel.close();
                    } catch (IOException e) {
                        LOG.error(StringUtils.stringifyException(e));
                    }
                }
                channelMap.remove(itemKey);
            }

            public boolean downloadStarting(int itemId, String itemKey, int contentLength) {
                LOG.info("Key:" + itemKey + " DownloadStarting - ContentLength:" + contentLength);
                File file = new File("/tmp/" + itemKey);
                if (file.exists())
                    file.delete();
                file.getParentFile().mkdirs();
                FileOutputStream fileHandle = null;
                try {
                    fileHandle = new FileOutputStream(file);
                    //LOG.info("Key:" + itemKey + " Created File:" + file.getAbsolutePath());
                    channelMap.put(itemKey, fileHandle.getChannel());
                } catch (IOException e) {
                    LOG.error(StringUtils.stringifyException(e));
                    if (fileHandle != null)
                        try {
                            fileHandle.close();
                        } catch (IOException e1) {
                        }
                    return false;
                }

                return true;
            }
        });

        downloader.fetchItem(itemToFetch);

        downloader.waitForCompletion();
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }

}

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From source file:MainClass.java

public static void main(String[] args) {
    String[] phrases = { "A", "B 1", "C 1.3" };
    String dirname = "C:/test";
    String filename = "Phrases.txt";
    File dir = new File(dirname);
    File aFile = new File(dir, filename);
    FileOutputStream outputFile = null;
    try {/* w ww  . ja  va 2 s  .  c  o  m*/
        outputFile = new FileOutputStream(aFile, true);
    } catch (FileNotFoundException e) {
        e.printStackTrace(System.err);
    }
    FileChannel outChannel = outputFile.getChannel();
    ByteBuffer buf = ByteBuffer.allocate(1024);
    System.out.println(buf.position());
    System.out.println(buf.limit());
    System.out.println(buf.capacity());
    CharBuffer charBuf = buf.asCharBuffer();
    System.out.println(charBuf.position());
    System.out.println(charBuf.limit());
    System.out.println(charBuf.capacity());
    Formatter formatter = new Formatter(charBuf);
    int number = 0;
    for (String phrase : phrases) {
        formatter.format("%n %s", ++number, phrase);
        System.out.println(charBuf.position());
        System.out.println(charBuf.limit());
        System.out.println(charBuf.capacity());
        charBuf.flip();
        System.out.println(charBuf.position());
        System.out.println(charBuf.limit());
        System.out.println(charBuf.length());
        buf.limit(2 * charBuf.length()); // Set byte buffer limit
        System.out.println(buf.position());
        System.out.println(buf.limit());
        System.out.println(buf.remaining());
        try {
            outChannel.write(buf);
            buf.clear();
            charBuf.clear();
        } catch (IOException e) {
            e.printStackTrace(System.err);
        }
    }
    try {
        outputFile.close();
    } catch (IOException e) {
        e.printStackTrace(System.err);
    }
}

---

From source file:Lock.java

public static void main(String args[]) throws IOException, InterruptedException {
    RandomAccessFile file = null; // The file we'll lock
    FileChannel f = null; // The channel to the file
    FileLock lock = null; // The lock object we hold

    try { // The finally clause closes the channel and releases the lock
        // We use a temporary file as the lock file.
        String tmpdir = System.getProperty("java.io.tmpdir");
        String filename = Lock.class.getName() + ".lock";
        File lockfile = new File(tmpdir, filename);

        // Create a FileChannel that can read and write that file.
        // Note that we rely on the java.io package to open the file,
        // in read/write mode, and then just get a channel from it.
        // This will create the file if it doesn't exit. We'll arrange
        // for it to be deleted below, if we succeed in locking it.
        file = new RandomAccessFile(lockfile, "rw");
        f = file.getChannel();/*from ww  w.j a va  2  s .  c om*/

        // Try to get an exclusive lock on the file.
        // This method will return a lock or null, but will not block.
        // See also FileChannel.lock() for a blocking variant.
        lock = f.tryLock();

        if (lock != null) {
            // We obtained the lock, so arrange to delete the file when
            // we're done, and then write the approximate time at which
            // we'll relinquish the lock into the file.
            lockfile.deleteOnExit(); // Just a temporary file

            // First, we need a buffer to hold the timestamp
            ByteBuffer bytes = ByteBuffer.allocate(8); // a long is 8 bytes

            // Put the time in the buffer and flip to prepare for writing
            // Note that many Buffer methods can be "chained" like this.
            bytes.putLong(System.currentTimeMillis() + 10000).flip();

            f.write(bytes); // Write the buffer contents to the channel
            f.force(false); // Force them out to the disk
        } else {
            // We didn't get the lock, which means another instance is
            // running. First, let the user know this.
            System.out.println("Another instance is already running");

            // Next, we attempt to read the file to figure out how much
            // longer the other instance will be running. Since we don't
            // have a lock, the read may fail or return inconsistent data.
            try {
                ByteBuffer bytes = ByteBuffer.allocate(8);
                f.read(bytes); // Read 8 bytes from the file
                bytes.flip(); // Flip buffer before extracting bytes
                long exittime = bytes.getLong(); // Read bytes as a long
                // Figure out how long that time is from now and round
                // it to the nearest second.
                long secs = (exittime - System.currentTimeMillis() + 500) / 1000;
                // And tell the user about it.
                System.out.println("Try again in about " + secs + " seconds");
            } catch (IOException e) {
                // This probably means that locking is enforced by the OS
                // and we were prevented from reading the file.
            }

            // This is an abnormal exit, so set an exit code.
            System.exit(1);
        }

        // Simulate a real application by sleeping for 10 seconds.
        System.out.println("Starting...");
        Thread.sleep(10000);
        System.out.println("Exiting.");
    } finally {
        // Always release the lock and close the file
        // Closing the RandomAccessFile also closes its FileChannel.
        if (lock != null && lock.isValid())
            lock.release();
        if (file != null)
            file.close();
    }
}

---

From source file:Main.java

private static void writeFileFromBytes(final File file, final byte[] bytes) {
    FileChannel fc = null;
    try {/*from w  w w  .  ja v  a 2 s.c o  m*/
        fc = new FileOutputStream(file, false).getChannel();
        fc.write(ByteBuffer.wrap(bytes));
        fc.force(true);
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        try {
            if (fc != null) {
                fc.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

---

From source file:Main.java

public static void toFile(ByteBuffer buffer, File file) throws IOException {
    RandomAccessFile raf = null;/*from   w w w.j  a v  a  2  s  . c om*/
    FileChannel channel = null;
    try {
        raf = new RandomAccessFile(file, "rw");
        channel = raf.getChannel();
        channel.write(buffer);
        channel.force(false /*metadata*/);
        channel.close();
        raf.close();
    } finally {
        if (channel != null) {
            try {
                channel.close();
            } catch (IOException e) {
                // Ignored.
            }
        }
        if (raf != null) {
            try {
                raf.close();
            } catch (IOException e) {
                // Ignored.
            }
        }
    }
}

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From source file:Main.java

/** Copia un fichero.
 * @param source Fichero origen con el contenido que queremos copiar.
 * @param dest Fichero destino de los datos.
 * @throws IOException SI ocurre algun problema durante la copia */
public static void copyFile(final File source, final File dest) throws IOException {
    if (source == null || dest == null) {
        throw new IllegalArgumentException("Ni origen ni destino de la copia pueden ser nulos"); //$NON-NLS-1$
    }/* ww  w.ja  v a 2 s.  com*/

    final FileInputStream is = new FileInputStream(source);
    final FileOutputStream os = new FileOutputStream(dest);
    final FileChannel in = is.getChannel();
    final FileChannel out = os.getChannel();
    final MappedByteBuffer buf = in.map(FileChannel.MapMode.READ_ONLY, 0, in.size());
    out.write(buf);

    in.close();
    out.close();
    is.close();
    os.close();

}

---

From source file:yui.classes.utils.IOUtils.java

public static void fastCopy(File source, File dest) throws IOException {
    FileInputStream fi = new FileInputStream(source);
    FileChannel fic = fi.getChannel();
    MappedByteBuffer mbuf = fic.map(FileChannel.MapMode.READ_ONLY, 0, source.length());
    fic.close();/*from   ww w .  java 2 s  .co m*/
    fi.close();

    FileOutputStream fo = new FileOutputStream(dest);
    FileChannel foc = fo.getChannel();
    foc.write(mbuf);
    foc.close();
    fo.close();

}

---

From source file:com.alibaba.otter.shared.common.utils.NioUtilsPerformance.java

public static void channelTest(File source, File target) throws Exception {
    FileInputStream fis = null;/*from w w w . j  ava2  s .com*/
    FileOutputStream fos = null;
    try {
        fis = new FileInputStream(source);
        fos = new FileOutputStream(target);
        FileChannel sChannel = fis.getChannel();
        FileChannel tChannel = fos.getChannel();

        target.createNewFile();

        ByteBuffer buffer = ByteBuffer.allocate(16 * 1024);
        while (sChannel.read(buffer) > 0) {
            buffer.flip();
            tChannel.write(buffer);
            buffer.clear();
        }

        tChannel.close();
        sChannel.close();
    } finally {
        IOUtils.closeQuietly(fis);
        IOUtils.closeQuietly(fos);
    }
}

---

From source file:MainClass.java

private static void createFile() throws Exception {
    long[] primes = new long[] { 1, 2, 3, 5, 7 };
    File aFile = new File("C:/primes.bin");
    FileOutputStream outputFile = new FileOutputStream(aFile);
    FileChannel file = outputFile.getChannel();
    final int BUFFERSIZE = 100;
    ByteBuffer buf = ByteBuffer.allocate(BUFFERSIZE);
    LongBuffer longBuf = buf.asLongBuffer();
    int primesWritten = 0;
    while (primesWritten < primes.length) {
        longBuf.put(primes, primesWritten, min(longBuf.capacity(), primes.length - primesWritten));
        buf.limit(8 * longBuf.position());

        file.write(buf);
        primesWritten += longBuf.position();
        longBuf.clear();//from   w w w .  ja  v  a2s .  co m
        buf.clear();
    }
    System.out.println("File written is " + file.size() + "bytes.");
    outputFile.close();
}

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From source file:ja.lingo.engine.util.EngineFiles.java

private static void appendFile(String fileName, FileOutputStream fos, boolean prependWithLength)
        throws IOException {
    FileInputStream fis = new FileInputStream(fileName);
    FileChannel fic = fis.getChannel();
    FileChannel foc = fos.getChannel();

    ByteBuffer buffer = ByteBuffer.allocate(COPY_BUFFER_SIZE);

    // put header: length (1 int = 4 bytes)
    if (prependWithLength) {
        buffer.putInt((int) new File(fileName).length());
    }/*from  w  ww  . j a va  2  s  .c om*/

    // put body
    do {
        buffer.flip();
        foc.write(buffer);
        buffer.clear();
    } while (fic.read(buffer) != -1);
    fic.close();
    // NOTE: do not close 'foc'

    Files.delete(fileName);
}

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