Example usage for java.nio.channels FileChannel map

List of usage examples for java.nio.channels FileChannel map

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Introduction

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

Prototype

public abstract MappedByteBuffer map(MapMode mode, long position, long size) throws IOException;

Source Link

Document

Maps a region of this channel's file directly into memory.

Usage

From source file:net.simon04.guavavfs.VirtualFiles.java

private static MappedByteBuffer map(RandomAccessFile raf, MapMode mode, long size) throws IOException {
    Closer closer = Closer.create();//from   ww  w.  j a  v  a 2s.  co  m
    try {
        FileChannel channel = closer.register(raf.getChannel());
        return channel.map(mode, 0, size);
    } catch (Throwable e) {
        throw closer.rethrow(e);
    } finally {
        closer.close();
    }
}

From source file:org.lenskit.data.packed.BinaryRatingDAO.java

/**
 * Open a binary rating DAO./*from w ww  . j  a v  a  2 s  .co m*/
 *
 * @param file The file to open.
 * @return A DAO backed by {@code file}.
 * @throws IOException If there is
 */
public static BinaryRatingDAO open(File file) throws IOException {
    try (FileInputStream input = new FileInputStream(file)) {
        FileChannel channel = input.getChannel();
        BinaryHeader header = BinaryHeader.read(channel);
        logger.info("Loading DAO with {} ratings of {} items from {} users", header.getRatingCount(),
                header.getItemCount(), header.getUserCount());
        // the channel position has been advanced to end of header

        ByteBuffer data = channel.map(FileChannel.MapMode.READ_ONLY, channel.position(),
                header.getRatingDataSize());
        channel.position(channel.position() + header.getRatingDataSize());

        ByteBuffer tableBuffer = channel.map(FileChannel.MapMode.READ_ONLY, channel.position(),
                channel.size() - channel.position());
        BinaryIndexTable utbl = BinaryIndexTable.fromBuffer(header.getUserCount(), tableBuffer);
        BinaryIndexTable itbl = BinaryIndexTable.fromBuffer(header.getItemCount(), tableBuffer);

        return new BinaryRatingDAO(file, header, data, utbl, itbl, header.getRatingCount(), Long.MAX_VALUE);
    }
}

From source file:HSqlPrimerDesign.java

@Deprecated
public static String readFile(String file) throws IOException {
    FileChannel inChannel = new RandomAccessFile(file, "r").getChannel();
    MappedByteBuffer buffer = inChannel.map(FileChannel.MapMode.READ_ONLY, 0, inChannel.size());
    char ch;/*from  ww  w  .  j  ava2 s .com*/
    StringBuffer line = new StringBuffer();
    for (int i = 0; i < buffer.limit(); i++) {
        ch = ((char) buffer.get());
        line.append(ch);
    }
    return line.toString();
}

From source file:marytts.util.io.FileUtils.java

public static void copy(File source, File dest) throws IOException {
    FileChannel in = null, out = null;
    try {//from  w  w  w .j a va  2s  .c om
        System.out.println("copying: " + source + "\n    --> " + dest);
        in = new FileInputStream(source).getChannel();
        out = new FileOutputStream(dest).getChannel();
        MappedByteBuffer buf = in.map(FileChannel.MapMode.READ_ONLY, 0, in.size());
        out.write(buf);
    } catch (Exception e) {
        System.out.println("Error copying file " + source.getAbsolutePath() + " to " + dest.getAbsolutePath()
                + " : " + e.getMessage());
        throw new IOException();
    } finally {
        FileUtils.close(in, out);
    }
}

From source file:com.stimulus.archiva.store.MessageStore.java

public static void copy(File source, File dest) throws IOException {
    FileChannel in = null, out = null;
    try {//  w  w  w .java 2s .  co m
        in = new FileInputStream(source).getChannel();
        out = new FileOutputStream(dest).getChannel();

        long size = in.size();
        MappedByteBuffer buf = in.map(FileChannel.MapMode.READ_ONLY, 0, size);

        out.write(buf);

    } finally {
        if (in != null)
            in.close();
        if (out != null)
            out.close();
    }
}

From source file:it.polito.tellmefirst.parsing.TXTparser.java

public String txtToText(File file) throws TMFVisibleException {
    LOG.debug("[txtToText] - BEGIN");
    String result;//from   w w w . ja  va2 s  .c  o m
    try {
        FileInputStream stream = new FileInputStream(file);
        FileChannel fc = stream.getChannel();
        MappedByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, fc.size());
        stream.close();
        result = Charset.defaultCharset().decode(bb).toString();
    } catch (Exception e) {
        LOG.error("[txtToText] - EXCEPTION: ", e);
        throw new TMFVisibleException(
                "Problem parsing the file: the TXT document you uploaded seems malformed.");
    }
    LOG.debug("[txtToText] - END");
    return result;
}

From source file:com.example.psumaps.MapView.java

public static Bitmap convertToMutable(Bitmap imgIn) {
    try {/*from   w ww  . ja  va 2 s .  c o m*/
        // this is the file going to use temporally to save the bytes.
        // This file will not be a image, it will store the raw image data.
        File file = new File(Environment.getExternalStorageDirectory() + File.separator + "temp.tmp");

        // Open an RandomAccessFile
        // Make sure you have added uses-permission
        // android:name="android.permission.WRITE_EXTERNAL_STORAGE"
        // into AndroidManifest.xml file
        RandomAccessFile randomAccessFile = new RandomAccessFile(file, "rw");

        // get the width and height of the source bitmap.
        int width = imgIn.getWidth();
        int height = imgIn.getHeight();
        Bitmap.Config type = imgIn.getConfig();

        // Copy the byte to the file
        // Assume source bitmap loaded using options.inPreferredConfig =
        // Config.ARGB_8888;
        FileChannel channel = randomAccessFile.getChannel();
        MappedByteBuffer map = channel.map(FileChannel.MapMode.READ_WRITE, 0, imgIn.getRowBytes() * height);
        imgIn.copyPixelsToBuffer(map);
        // recycle the source bitmap, this will be no longer used.
        imgIn.recycle();
        System.gc();// try to force the bytes from the imgIn to be released

        // Create a new bitmap to load the bitmap again. Probably the memory
        // will be available.
        imgIn = Bitmap.createBitmap(width, height, type);
        map.position(0);
        // load it back from temporary
        imgIn.copyPixelsFromBuffer(map);
        // close the temporary file and channel , then delete that also
        channel.close();
        randomAccessFile.close();

        // delete the temp file
        file.delete();

    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

    return imgIn;
}

From source file:org.squidy.designer.components.pdf.PDFPane.java

public PDFPane(String pdfFileLoc) {
    super();//  w w  w . j  a  va 2s. co m
    try {
        // load a pdf from a byte buffer
        File file = new File(pdfFileLoc);
        RandomAccessFile raf = new RandomAccessFile(file, "r");
        FileChannel channel = raf.getChannel();
        ByteBuffer buf = channel.map(FileChannel.MapMode.READ_ONLY, 0, channel.size());
        PDFFile pdffile = new PDFFile(buf);
        pdfComponents = new PagePanel[pdffile.getNumPages()];
        pageHeight = (int) pdffile.getPage(0).getHeight() + 3;
        pageWidth = (int) pdffile.getPage(0).getWidth() + 1;

        for (int i = 0; i < pdfComponents.length; i++) {
            PagePanel p = new PagePanel();
            p.setBackground(Color.BLACK);
            p.setPreferredSize(new Dimension(pageWidth, pageHeight));
            PSwing ps = new PSwing(p);

            ps.setOffset(0, i * pageHeight);
            addChild(ps);
            p.showPage(pdffile.getPage(i));
        }
    } catch (IOException e) {
        if (LOG.isErrorEnabled()) {
            LOG.error("Error in " + PDFPane.class.getName() + ".", e);
        }
        System.out.println(e.getMessage());
    }
}

From source file:org.lnicholls.galleon.util.Tools.java

public static InputStream getInputStream(File file) {
    try {//from  w ww  .  j  a v a  2 s  .  c om
        FileChannel roChannel = new RandomAccessFile(file, "r").getChannel();
        final ByteBuffer buf = roChannel.map(FileChannel.MapMode.READ_ONLY, 0, (int) roChannel.size());
        return new InputStream() {
            public synchronized int read() throws IOException {
                if (!buf.hasRemaining()) {
                    return -1;
                }
                return buf.get();
            }

            public synchronized int read(byte[] bytes, int off, int len) throws IOException {
                if (!buf.hasRemaining()) {
                    return -1;
                }
                len = Math.min(len, buf.remaining());
                buf.get(bytes, off, len);
                return len;
            }
        };
    } catch (Exception ex) {
        Tools.logException(Tools.class, ex, file.getAbsolutePath());
    }
    return null;
}

From source file:org.lnicholls.galleon.util.Tools.java

public static BufferedImage ImageIORead(File file) {
    System.gc();/*  w  ww .  ja v  a  2  s . c o  m*/
    try {
        FileChannel roChannel = new RandomAccessFile(file, "r").getChannel();
        final ByteBuffer buf = roChannel.map(FileChannel.MapMode.READ_ONLY, 0, (int) roChannel.size());
        return ImageIO.read(new InputStream() {
            public synchronized int read() throws IOException {
                if (!buf.hasRemaining()) {
                    return -1;
                }
                return buf.get();
            }

            public synchronized int read(byte[] bytes, int off, int len) throws IOException {
                if (!buf.hasRemaining()) {
                    return -1;
                }
                len = Math.min(len, buf.remaining());
                buf.get(bytes, off, len);
                return len;
            }
        });
    } catch (Exception ex) {
        Tools.logException(Tools.class, ex, file.getAbsolutePath());
    }

    try {
        return ImageIO.read(new FileInputStream(file));
    } catch (Exception ex) {
        Tools.logException(Tools.class, ex, file.getAbsolutePath());
    }
    return null;
}