Example usage for java.nio.channels FileChannel map

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:Main.java

public static Bitmap convertToMutable(Bitmap srcBitmap, String cacheDirPath, String tempFileName) {
    try {/*  w  w  w  .j av  a2 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.
        int index = tempFileName.lastIndexOf(".");
        if (index != -1)
            tempFileName = tempFileName.substring(0, index);
        File file = new File(cacheDirPath + File.separator + tempFileName + ".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 = srcBitmap.getWidth();
        int height = srcBitmap.getHeight();
        Config type = srcBitmap.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(MapMode.READ_WRITE, 0, srcBitmap.getRowBytes() * height);
        srcBitmap.copyPixelsToBuffer(map);
        // recycle the source bitmap, this will be no longer used.
        srcBitmap.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.
        srcBitmap = Bitmap.createBitmap(width, height, type);
        map.position(0);
        // load it back from temporary
        srcBitmap.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 srcBitmap;
}

From source file:Main.java

public static ByteBuffer fromFile(File file) throws IOException {
    RandomAccessFile raf = null;//  w  w  w . ja v  a  2 s.  c  o  m
    FileChannel channel = null;
    try {
        raf = new RandomAccessFile(file, "r");
        channel = raf.getChannel();
        return channel.map(FileChannel.MapMode.READ_ONLY, 0, file.length()).load();
    } finally {
        if (channel != null) {
            try {
                channel.close();
            } catch (IOException e) {
                // Ignored.
            }
        }
        if (raf != null) {
            try {
                raf.close();
            } catch (IOException e) {
                // Ignored.
            }
        }
    }
}

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"); //$NON-NLS-1$
    }// www . j av  a  2  s  . c  om

    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:com.twitter.ambrose.util.JSONUtil.java

public static String readFile(String path) throws IOException {
    FileInputStream stream = new FileInputStream(new File(path));
    try {/*from   w  w  w  .  j a  v  a 2s .  c om*/
        FileChannel fc = stream.getChannel();
        MappedByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, fc.size());
        return Charset.defaultCharset().decode(bb).toString();
    } finally {
        stream.close();
    }
}

From source file:org.springframework.hateoas.VndErrorsMarshallingTest.java

private static String readFile(org.springframework.core.io.Resource resource) throws IOException {

    FileInputStream stream = new FileInputStream(resource.getFile());

    try {/*from ww w. j a  va2s .  c  o m*/
        FileChannel fc = stream.getChannel();
        MappedByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, fc.size());
        return Charset.defaultCharset().decode(bb).toString();
    } finally {
        stream.close();
    }
}

From source file:edu.isi.webserver.FileUtil.java

public static String readFileContentsToString(File file) throws IOException {
    FileInputStream stream = new FileInputStream(file);
    try {// w  w w  . jav a  2s .  c o m
        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.defaultCharset().decode(bb).toString();
    } finally {
        stream.close();
    }
}

From source file:Main.java

private static byte[] readFile2Bytes(final File file) {
    FileChannel fc = null;
    try {/*ww  w . j av a 2 s.  c  o m*/
        fc = new RandomAccessFile(file, "r").getChannel();
        int size = (int) fc.size();
        MappedByteBuffer mbb = fc.map(FileChannel.MapMode.READ_ONLY, 0, size).load();
        byte[] data = new byte[size];
        mbb.get(data, 0, size);
        return data;
    } catch (IOException e) {
        e.printStackTrace();
        return null;
    } finally {
        try {
            if (fc != null) {
                fc.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

From source file:org.xlcloud.service.manager.VirtualClusterTemplateManagerImpl.java

private static String readFile(String path) throws IOException, FileNotFoundException {
    FileInputStream stream = new FileInputStream(new File(path));
    try {/*ww  w . j a va2 s . c  om*/
        FileChannel fc = stream.getChannel();
        MappedByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, fc.size());

        return Charset.defaultCharset().decode(bb).toString();
    } finally {
        stream.close();
    }
}

From source file:GrepSun.java

private static void grep(File f) throws IOException {

    // Open the file and then get a channel from the stream
    FileInputStream fis = new FileInputStream(f);
    FileChannel fc = fis.getChannel();

    // Get the file's size and then map it into memory
    int sz = (int) fc.size();
    MappedByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, sz);

    // Decode the file into a char buffer
    CharBuffer cb = decoder.decode(bb);

    // Perform the search
    grep(f, cb);/*w w  w  .  j  a va2  s .c  om*/

    // Close the channel and the stream
    fc.close();
}

From source file:edu.usf.cutr.siri.SiriParserJacksonExample.java

/**
 * Read in input file to string/*from  w w w .jav  a 2  s  .  c  o m*/
 * @param file file containing the JSON or XML data
 * @return String representation of the JSON or XML file
 * @throws IOException
 */
private static String readFile(File file) throws IOException {
    FileInputStream stream = new FileInputStream(file);
    try {
        FileChannel fc = stream.getChannel();
        MappedByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, fc.size());
        return Charset.defaultCharset().decode(bb).toString();
    } finally {
        stream.close();
    }
}