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:org.oscarehr.document.web.ManageDocumentAction.java

public ActionForward view2(ActionMapping mapping, ActionForm form, HttpServletRequest request,
        HttpServletResponse response) throws Exception {

    // TODO: NEED TO CHECK FOR ACCESS
    String doc_no = request.getParameter("doc_no");
    log.debug("Document No :" + doc_no);

    LogAction.addLog((String) request.getSession().getAttribute("user"), LogConst.READ, LogConst.CON_DOCUMENT,
            doc_no, request.getRemoteAddr());

    Document d = documentDAO.getDocument(doc_no);
    log.debug("Document Name :" + d.getDocfilename());

    // TODO: Right now this assumes it's a pdf which it shouldn't

    response.setContentType("image/png");
    // response.setHeader("Content-Disposition", "attachment;filename=\"" + filename+ "\"");
    // read the file name.
    File file = new File(EDocUtil.getDocumentPath(d.getDocfilename()));

    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);
    // draw the first page to an image
    PDFPage ppage = pdffile.getPage(0);/*from   w  w w.j  a  v  a 2 s . co m*/

    log.debug("WIDTH " + (int) ppage.getBBox().getWidth() + " height " + (int) ppage.getBBox().getHeight());

    // get the width and height for the doc at the default zoom
    Rectangle rect = new Rectangle(0, 0, (int) ppage.getBBox().getWidth(), (int) ppage.getBBox().getHeight());

    log.debug("generate the image");
    Image img = ppage.getImage(rect.width, rect.height, // width & height
            rect, // clip rect
            null, // null for the ImageObserver
            true, // fill background with white
            true // block until drawing is done
    );

    log.debug("about to Print to stream");
    ServletOutputStream outs = response.getOutputStream();

    RenderedImage rendImage = (RenderedImage) img;
    ImageIO.write(rendImage, "png", outs);
    outs.flush();
    outs.close();
    return null;
}

From source file:eu.medsea.mimeutil.detector.OpendesktopMimeDetector.java

private void init(final String mimeCacheFile) {
    String cacheFile = mimeCacheFile;
    if (!new File(cacheFile).exists()) {
        cacheFile = internalMimeCacheFile;

    }/*from w  ww.ja  v  a2  s .  c  o m*/
    // Map the mime.cache file as a memory mapped file
    FileChannel rCh = null;
    try {
        RandomAccessFile raf = null;
        raf = new RandomAccessFile(cacheFile, "r");
        rCh = (raf).getChannel();
        content = rCh.map(FileChannel.MapMode.READ_ONLY, 0, rCh.size());

        // Read all of the MIME type from the Alias list
        initMimeTypes();

        if (log.isDebugEnabled()) {
            log.debug("Registering a FileWatcher for [" + cacheFile + "]");
        }
        TimerTask task = new FileWatcher(new File(cacheFile)) {
            protected void onChange(File file) {
                initMimeTypes();
            }
        };

        timer = new Timer();
        // repeat the check every 10 seconds
        timer.schedule(task, new Date(), 10000);

    } catch (Exception e) {
        throw new MimeException(e);
    } finally {
        if (rCh != null) {
            try {
                rCh.close();
            } catch (Exception e) {
                log.error(e.getLocalizedMessage(), e);
            }
        }
    }
}

From source file:edu.cmu.graphchi.shards.QueryShard.java

public QueryShard(String fileName, int shardNum, int numShards, VertexInterval interval, Config dbConfig)
        throws IOException {
    this.shardNum = shardNum;
    this.interval = interval;

    pinIndexToMemory = dbConfig.getBoolean("queryshard.pinindex");
    queryCacheSize = dbConfig.getInt("queryshard.cachesize");

    adjFile = new File(ChiFilenames.getFilenameShardsAdj(fileName, shardNum, numShards));
    numEdges = (int) (adjFile.length() / BYTES_PER_EDGE);

    FileChannel channel = new java.io.RandomAccessFile(adjFile, "rw").getChannel();
    adjBuffer = channel.map(FileChannel.MapMode.READ_WRITE, 0, adjFile.length()).asLongBuffer();
    channel.close();//ww  w .  j a  v  a2s .c o  m

    index = (pinIndexToMemory ? null : createSparseIndex());

    loadPointers();
    loadInEdgeStartBuffer();
}

From source file:ome.io.nio.RomioPixelBuffer.java

/**
 * Implemented as specified by {@link PixelBuffer} I/F.
 * @see PixelBuffer#getRegion(Integer, Long)
*///from   w  ww.  j a  v  a  2s.c  o m
public PixelData getRegion(Integer size, Long offset) throws IOException {
    FileChannel fileChannel = getFileChannel();

    /*
     * fileChannel should not be "null" as it will throw an exception if
     * there happens to be an error.
     */

    MappedByteBuffer b = fileChannel.map(MapMode.READ_ONLY, offset, size);
    return new PixelData(pixels.getPixelsType().getValue(), b);
}

From source file:org.cytobank.fcs_files.events.MemoryEvents.java

protected synchronized boolean writeOut() {
    if (memoryEventsArray == null)
        return false;

    File memoryEventsArrayOnDisk = null;

    synchronized (memoryEventsArray) {
        memoryEventsArrayOnDisk = memoryEventsArray.getOnDisk();

        if (memoryEventsArrayOnDisk != null || events == null)
            return false;

        RandomAccessFile randomAccessFile = null;
        FileChannel fileChannel = null;

        try {//from   w  ww  .  ja  v a2 s. c  o  m
            memoryEventsArrayOnDisk = File.createTempFile("memoryEventsArrayOnDisk", "evt");
            memoryEventsArrayOnDisk.deleteOnExit();
            randomAccessFile = new RandomAccessFile(memoryEventsArrayOnDisk, "rw");
            fileChannel = randomAccessFile.getChannel();

            MappedByteBuffer mappedByteBuffer = fileChannel.map(MapMode.READ_WRITE, 0,
                    numberOfEvents * BYTES_PER_DOUBLE);
            DoubleBuffer doubleBuffer = mappedByteBuffer.asDoubleBuffer();
            doubleBuffer.put(events, 0, numberOfEvents);
            mappedByteBuffer.force();
            fileChannel.close();
            randomAccessFile.close();

            memoryEventsArray.setOnDisk(memoryEventsArrayOnDisk);

        } catch (IOException ioe) {
            logger.log(Level.INFO, "::::: Failed to write out MemoryEventsArray :::::", ioe);
            if (memoryEventsArrayOnDisk != null) {
                memoryEventsArrayOnDisk.delete();
                memoryEventsArrayOnDisk = null;
            }
        } finally {
            memoryEventsArrayOnDisk.delete();
        }
    }

    return true;

}

From source file:automenta.knowtention.channel.LineFileChannel.java

@Override
public void run() {

    FileInputStream fileInputStream = null;
    FileChannel channel = null;
    ByteBuffer buffer = null;//from  w  w w . ja  va  2 s .  co m
    LinkedList<String> lines = new LinkedList();
    StringBuilder builder = new StringBuilder();
    long lastSize = -1, lastLastModified = -1;

    while (running) {
        try {
            Thread.sleep(delayPeriodMS);
        } catch (InterruptedException ex) {
        }

        lines.clear();
        try {
            fileInputStream = new FileInputStream(file);

            channel = fileInputStream.getChannel();

            long lastModified = file.lastModified();
            long csize = channel.size();
            if ((lastModified == lastLastModified) && (csize == lastSize)) { //also check file update time?
                fileInputStream.close();
                continue;
            }

            int currentPos = (int) csize;

            buffer = channel.map(FileChannel.MapMode.READ_ONLY, 0, csize);
            buffer.position(currentPos);
            lastSize = csize;
            lastLastModified = lastModified;

            int count = 0;

            for (long i = csize - 1; i >= 0; i--) {

                char c = (char) buffer.get((int) i);

                if (c == '\n') {
                    count++;
                    builder.reverse();
                    lines.addFirst(builder.toString());
                    if (count == numLines) {
                        break;
                    }
                    builder.setLength(0);
                } else
                    builder.append(c);
            }

            update(lines);

            lines.clear();
            buffer.clear();
            channel.close();
            fileInputStream.close();
            fileInputStream = null;

        } catch (Exception ex) {
            Logger.getLogger(LineFileChannel.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
    try {
        channel.close();
    } catch (IOException ex) {
        Logger.getLogger(LineFileChannel.class.getName()).log(Level.SEVERE, null, ex);
    }
}

From source file:edu.cmu.graphchi.shards.QueryShard.java

private void loadInEdgeStartBuffer() throws IOException {
    File inEdgeStartBufferFile = new File(
            ChiFilenames.getFilenameShardsAdjStartIndices(adjFile.getAbsolutePath()));
    FileChannel inEdgeStartChannel = new java.io.RandomAccessFile(inEdgeStartBufferFile, "r").getChannel();
    inEdgeStartBuffer = inEdgeStartChannel.map(FileChannel.MapMode.READ_ONLY, 0, inEdgeStartBufferFile.length())
            .asIntBuffer();//from  ww w .  j a  v a 2  s . c  om
    inEdgeStartChannel.close();
}

From source file:edu.cmu.graphchi.shards.QueryShard.java

void loadPointers() throws IOException {
    File pointerFile = new File(ChiFilenames.getFilenameShardsAdjPointers(adjFile.getAbsolutePath()));
    if (!pinIndexToMemory) {
        FileChannel ptrFileChannel = new java.io.RandomAccessFile(pointerFile, "r").getChannel();
        pointerIdxBuffer = ptrFileChannel.map(FileChannel.MapMode.READ_ONLY, 0, pointerFile.length())
                .asLongBuffer();/*from   w  w w .  j  ava  2s .  co  m*/
        ptrFileChannel.close();
    } else {
        byte[] data = new byte[(int) pointerFile.length()];

        if (data.length == 0)
            return;
        totalOrigSize += data.length;

        FileInputStream fis = new FileInputStream(pointerFile);
        int i = 0;
        while (i < data.length) {
            i += fis.read(data, i, data.length - i);
        }
        fis.close();

        pointerIdxBuffer = ByteBuffer.wrap(data).asLongBuffer();

        long[] vertices = new long[pointerIdxBuffer.capacity() - 1];
        long[] offs = new long[vertices.length];

        for (int j = 0; j < vertices.length; j++) {
            long x = pointerIdxBuffer.get(j);
            vertices[j] = VertexIdTranslate.getVertexId(x);
            offs[j] = VertexIdTranslate.getAux(x);
        }

        boolean extraZero = (offs.length > 1 && offs[1] == offs[0]);
        if (extraZero) {
            vertices = Arrays.copyOfRange(vertices, 1, vertices.length);
            offs = Arrays.copyOfRange(offs, 1, offs.length);
        }

        gammaSeqVertices = new IncreasingEliasGammaSeq(vertices);
        gammaSeqOffs = new IncreasingEliasGammaSeq(offs);

        totalPinnedSize += gammaSeqVertices.sizeInBytes();
        totalPinnedSize += gammaSeqOffs.sizeInBytes();
        pointerIdxBuffer = null;

    }
}

From source file:org.geotools.data.shapefile.ShpFiles.java

/**
 * Internal method that the file channel decorators will call to allow reuse of the memory mapped
 * buffers/*from w  ww. j  a  v  a  2 s.  c  o m*/
 * 
 * @param wrapped
 * @param url
 * @param mode
 * @param position
 * @param size
 * @return
 * @throws IOException
 */
MappedByteBuffer map(FileChannel wrapped, URL url, MapMode mode, long position, long size) throws IOException {
    if (memoryMapCacheEnabled) {
        return mapCache.map(wrapped, url, mode, position, size);
    } else {
        return wrapped.map(mode, position, size);
    }
}

From source file:adept.io.Reader.java

/**
 * Reads specified file into a string./*  w ww  . j a  va 2  s  .  co m*/
 *
 * @param path the path
 * @return the string
 */
public String readFileIntoString(String path) {
    try {
        String absolutePath = path;
        //         String absolutePath = getAbsolutePathFromClasspathOrFileSystem(path);
        FileInputStream stream = new FileInputStream(new File(absolutePath));
        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 Charset.forName("UTF-8").decode(bb).toString();
        } finally {
            stream.close();
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
    return null;
}