Example usage for java.nio ByteBuffer allocate

List of usage examples for java.nio ByteBuffer allocate

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Introduction

In this page you can find the example usage for java.nio ByteBuffer allocate.

Prototype

public static ByteBuffer allocate(int capacity)

Source Link

Document

Creates a byte buffer based on a newly allocated byte array.

Usage

From source file:Main.java

/**
 * Finds the percentage of pixels that do are empty.
 *
 * @param bitmap input bitmap/*from   w  w  w. j  a v  a 2  s  . co  m*/
 * @return a value between 0.0 to 1.0 . Note the method will return 0.0 if either of bitmaps are null nor of same size.
 *
 */
public static float getTransparentPixelPercent(Bitmap bitmap) {

    if (bitmap == null) {
        return 0f;
    }

    ByteBuffer buffer = ByteBuffer.allocate(bitmap.getHeight() * bitmap.getRowBytes());
    bitmap.copyPixelsToBuffer(buffer);

    byte[] array = buffer.array();

    int len = array.length;
    int count = 0;

    for (int i = 0; i < len; i++) {
        if (array[i] == 0) {
            count++;
        }
    }

    return ((float) (count)) / len;
}

From source file:Main.java

public static byte[] aesIGEdecrypt(byte[] tmpAESiv, byte[] tmpAesKey, byte[] data) {
    try {//w w  w  . j  a va  2s .  c o m

        ByteBuffer out = ByteBuffer.allocate(data.length);

        byte[] iv2p = Arrays.copyOfRange(tmpAESiv, 0, tmpAESiv.length / 2);
        byte[] ivp = Arrays.copyOfRange(tmpAESiv, tmpAESiv.length / 2, tmpAESiv.length);

        int len = data.length / AES_BLOCK_SIZE;

        byte[] xorInput = null;
        byte[] xorOutput = null;

        SecretKeySpec keySpec = null;
        keySpec = new SecretKeySpec(tmpAesKey, "AES");
        Cipher cipher = null;
        cipher = Cipher.getInstance("AES/ECB/NoPadding");
        cipher.init(Cipher.DECRYPT_MODE, keySpec);

        byte[] input = null;
        byte[] output = null;

        for (int i = 0; i < len; i++) {
            input = Arrays.copyOfRange(data, i * AES_BLOCK_SIZE, (i + 1) * AES_BLOCK_SIZE);
            xorInput = xor(input, ivp);
            output = cipher.doFinal(xorInput);
            xorOutput = xor(output, iv2p);
            out.put(xorOutput);

            ivp = xorOutput;
            iv2p = input;
        }
        return out.array();
    } catch (NoSuchAlgorithmException e) {
        e.printStackTrace();
    } catch (NoSuchPaddingException e) {
        e.printStackTrace();
    } catch (IllegalBlockSizeException e) {
        e.printStackTrace();
    } catch (BadPaddingException e) {
        e.printStackTrace();
    } catch (InvalidKeyException e) {
        e.printStackTrace();
    }

    return null;
}

From source file:Main.java

public static String readString(String filePath) {
    File file = new File(filePath);
    if (!file.exists())
        return null;

    FileInputStream fileInput = null;
    FileChannel channel = null;//from w w  w .  j  a va2s . c  o m
    try {
        fileInput = new FileInputStream(filePath);
        channel = fileInput.getChannel();
        ByteBuffer buffer = ByteBuffer.allocate((int) channel.size());
        channel.read(buffer);

        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();
        byteArrayOutputStream.write(buffer.array());
        return byteArrayOutputStream.toString();
    } catch (Exception e) {
    } finally {

        if (fileInput != null) {
            try {
                fileInput.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }

        if (channel != null) {
            try {
                channel.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    return null;
}

From source file:MainClass.java

private static void test() throws Exception {
    long[] primes = new long[] { 1, 2, 3, 5, 7 };
    File aFile = new File("C:/test/primes.txt");
    FileOutputStream outputFile = null;
    outputFile = new FileOutputStream(aFile);
    FileChannel file = outputFile.getChannel();
    ByteBuffer[] buffers = new ByteBuffer[3];
    buffers[0] = ByteBuffer.allocate(8);
    buffers[2] = ByteBuffer.allocate(8);
    String primeStr = null;//from ww  w. j  ava2  s  . c o  m
    for (long prime : primes) {
        primeStr = "prime = " + prime;
        buffers[0].putDouble((double) primeStr.length()).flip();
        buffers[1] = ByteBuffer.allocate(primeStr.length());
        buffers[1].put(primeStr.getBytes()).flip();
        buffers[2].putLong(prime).flip();
        file.write(buffers);
        buffers[0].clear();
        buffers[2].clear();
    }
    System.out.println("File written is " + file.size() + "bytes.");
    outputFile.close();
}

From source file:Main.java

public static BigInteger getZ(ArrayList<byte[]> c1, ArrayList<byte[]> c2, BigInteger p) {
    BigInteger z = BigInteger.ZERO;

    //TODO: make sure c1 and c2 are of the same size
    int size = c1.size();
    if (size > c2.size()) {
        size = c2.size();//from www.  jav a2s.c om
    }

    for (int i = 0; i < size; i++) {
        BigInteger c1BI = new BigInteger(1, c1.get(i));
        BigInteger c2BI = new BigInteger(1, c2.get(i));
        BigInteger exp = new BigInteger(1, ByteBuffer.allocate(8).putLong((long) Math.pow(2, i)).array());

        z = z.add((c1BI.multiply(c2BI)).modPow(exp, p));
        Log.d("CeCk", "z calculation " + i + "/" + size + " round");
    }
    return z.mod(p);
}

From source file:Main.java

/**
 * Combine messages in an array and put a size header before each message
 * @param array/*from  w w  w .j  a v a  2  s  .  co  m*/
 * @return
 */
public static byte[] compileMessages(ArrayList<byte[]> array) {

    int bufferSize = 0;
    for (int i = 0; i < array.size(); i++) {
        byte[] thisByte = array.get(i);
        bufferSize += (4 + thisByte.length);
    }

    byte[] buffer = new byte[bufferSize];

    int pointer = 0; // used to index the next empty byte to fill
    for (int i = 0; i < array.size(); i++) {
        int thisSize = array.get(i).length;
        System.arraycopy(ByteBuffer.allocate(4).putInt(thisSize).array(), 0, buffer, pointer, 4);
        System.arraycopy(array.get(i), 0, buffer, pointer + 4, thisSize);
        pointer += (4 + thisSize);
    }

    return buffer;
}

From source file:Main.java

/**
 * Convert from singed 16-bit PCM to 32-bit float PCM.
 * @param byteArray byte array/* w ww  .j  av  a2  s  .  co m*/
 * @return byte array
 */
public static byte[] convert16BitTo32Bit(final byte[] byteArray) {
    float[] audioDataF = shortToFloat(byteToShort(byteArray));
    for (int i = 0; i < audioDataF.length; i++) {
        audioDataF[i] /= 32768.0;
    }

    FloatBuffer fb = FloatBuffer.wrap(audioDataF);
    ByteBuffer byteBuffer = ByteBuffer.allocate(fb.capacity() * 4);
    byteBuffer.order(ByteOrder.LITTLE_ENDIAN);
    byteBuffer.asFloatBuffer().put(fb);
    return byteBuffer.array();
}

From source file:Main.java

/**
 * Compares two bitmaps and gives the percentage of similarity
 *
 * @param bitmap1 input bitmap 1//w w  w  .j av a2 s . com
 * @param bitmap2 input bitmap 2
 * @return a value between 0.0 to 1.0 . Note the method will return 0.0 if either of bitmaps are null nor of same size.
 *
 */
public static float compareEquivalance(Bitmap bitmap1, Bitmap bitmap2) {

    if (bitmap1 == null || bitmap2 == null || bitmap1.getWidth() != bitmap2.getWidth()
            || bitmap1.getHeight() != bitmap2.getHeight()) {
        return 0f;
    }

    ByteBuffer buffer1 = ByteBuffer.allocate(bitmap1.getHeight() * bitmap1.getRowBytes());
    bitmap1.copyPixelsToBuffer(buffer1);

    ByteBuffer buffer2 = ByteBuffer.allocate(bitmap2.getHeight() * bitmap2.getRowBytes());
    bitmap2.copyPixelsToBuffer(buffer2);

    byte[] array1 = buffer1.array();
    byte[] array2 = buffer2.array();

    int len = array1.length; // array1 and array2 will be of some length.
    int count = 0;

    for (int i = 0; i < len; i++) {
        if (array1[i] == array2[i]) {
            count++;
        }
    }

    return ((float) (count)) / len;
}

From source file:IOUtilities.java

/**
 * Copy ALL available data from one stream into another
 * @param in//from w ww. j  av  a2 s  . co  m
 * @param out
 * @throws IOException
 */
public static void copy(InputStream in, OutputStream out) throws IOException {
    ReadableByteChannel source = Channels.newChannel(in);
    WritableByteChannel target = Channels.newChannel(out);

    ByteBuffer buffer = ByteBuffer.allocate(16 * 1024);
    while (source.read(buffer) != -1) {
        buffer.flip(); // Prepare the buffer to be drained
        while (buffer.hasRemaining()) {
            target.write(buffer);
        }
        buffer.clear(); // Empty buffer to get ready for filling
    }

    source.close();
    target.close();

}

From source file:Main.java

/**
 * Return a BCD representation of an integer as a 4-byte array.
 * @param i int//from w ww. j a  va  2  s . com
 * @return  byte[4]
 */
public static byte[] intToBcdArray(int i) {
    if (i < 0)
        throw new IllegalArgumentException("Argument cannot be a negative integer.");

    StringBuilder binaryString = new StringBuilder();

    while (true) {
        int quotient = i / 10;
        int remainder = i % 10;
        String nibble = String.format("%4s", Integer.toBinaryString(remainder)).replace(' ', '0');
        binaryString.insert(0, nibble);

        if (quotient == 0) {
            break;
        } else {
            i = quotient;
        }
    }

    return ByteBuffer.allocate(4).putInt(Integer.parseInt(binaryString.toString(), 2)).array();
}