Example usage for java.lang System arraycopy

Introduction

In this page you can find the example usage for java.lang System arraycopy.

Prototype

@HotSpotIntrinsicCandidate
public static native void arraycopy(Object src, int srcPos, Object dest, int destPos, int length);

Source Link

Document

Copies an array from the specified source array, beginning at the specified position, to the specified position of the destination array.

Usage

From source file:Main.java

private final static String encode(byte[] d) {
    if (d == null)
        return null;

    byte data[] = new byte[d.length + 2];
    System.arraycopy(d, 0, data, 0, d.length);
    byte dest[] = new byte[(data.length / 3) * 4];

    // 3-byte to 4-byte conversion
    for (int sidx = 0, didx = 0; sidx < d.length; sidx += 3, didx += 4) {
        dest[didx] = (byte) ((data[sidx] >>> 2) & 077);
        dest[didx + 1] = (byte) ((data[sidx + 1] >>> 4) & 017 | (data[sidx] << 4) & 077);
        dest[didx + 2] = (byte) ((data[sidx + 2] >>> 6) & 003 | (data[sidx + 1] << 2) & 077);
        dest[didx + 3] = (byte) (data[sidx + 2] & 077);
    }/*from   w  ww .  j  ava 2 s  . co  m*/

    // 0-63 to ascii printable conversion
    for (int idx = 0; idx < dest.length; idx++) {
        if (dest[idx] < 26)
            dest[idx] = (byte) (dest[idx] + 'A');
        else if (dest[idx] < 52)
            dest[idx] = (byte) (dest[idx] + 'a' - 26);
        else if (dest[idx] < 62)
            dest[idx] = (byte) (dest[idx] + '0' - 52);
        else if (dest[idx] < 63)
            dest[idx] = (byte) '+';
        else
            dest[idx] = (byte) '/';
    }

    // add padding
    for (int idx = dest.length - 1; idx > (d.length * 4) / 3; idx--) {
        dest[idx] = (byte) '=';
    }
    return new String(dest);
}

From source file:Main.java

public static void flatten_2D_vector(float[][] src_vec, float[] target_vec) {
    int height = src_vec.length;
    int width = src_vec[0].length;
    for (int i = 0; i < height; i++) {
        System.arraycopy(src_vec[i], 0, target_vec, i * width, width);
    }// ww  w. ja  v  a  2s .  c  om
}

From source file:Main.java

public static byte[] insertBytes(byte[] target, int offset, int targetLength, byte[] insertion,
        int insertionLength) {
    byte result[] = new byte[(targetLength + insertionLength)];
    System.arraycopy(target, 0, result, 0, offset);
    System.arraycopy(insertion, 0, result, offset, insertionLength);
    System.arraycopy(target, offset, result, (insertionLength + offset), (targetLength - offset));
    return result;
}

From source file:Main.java

public static byte[] appendRandomBytes(int len, byte... b) {
    byte[] ret = new byte[len + b.length];
    System.arraycopy(b, 0, ret, 0, b.length);
    System.arraycopy(genRandomBytes(len), 0, ret, b.length, len);
    return ret;//from   w  w  w  .  ja va 2s  .c o  m
}

From source file:Main.java

static public Object extractArray(Object[] list, int pos, int n) {
    Class type = list.getClass().getComponentType();
    Object temp = Array.newInstance(type, n);
    System.arraycopy(list, pos, temp, 0, n);
    return temp;/*from   ww w .j  ava 2 s  .com*/
}

From source file:Main.java

/**
 * Returns a range of elements of source from start to end of the array.
 *//*  w  w  w  . j  a  v a2s. co  m*/
public static int[] arraySlice(int[] source, int start, int count) {

    int[] slice = new int[count];

    System.arraycopy(source, start, slice, 0, count);

    return slice;
}

From source file:Main.java

public static void top_k_competition(float[] response_array, int size, int k) {
    float[] copy_of_array = new float[size];
    System.arraycopy(response_array, 0, copy_of_array, 0, size);
    Arrays.sort(copy_of_array);/*from   w w w .  j  a  v  a  2  s  .  c o m*/

    for (int i = 0; i < size; i++) {
        if (response_array[i] < copy_of_array[size - k]) {
            response_array[i] = 0;
        } else {
            //response_array[i]= (response_array[i]- copy_of_array[size-k-1])/
            //      (copy_of_array[size-1]-copy_of_array[size-k-1]);
            response_array[i] = 1;
        }
    }
}

From source file:Main.java

public static byte[] subArray(byte[] byteInput, int offset, int length) {
    if (offset < 0 || offset + length > byteInput.length) {
        return null;
    }/*from  w  w w  . j  a  va  2 s  . c  o m*/
    byte[] rtArray = new byte[length];
    System.arraycopy(byteInput, offset, rtArray, 0, length);
    return rtArray;
}

From source file:Main.java

private static char[] getPaddedBytes(String source) {
    char[] converted = source.toCharArray();
    int requiredLength = 3 * ((converted.length + 2) / 3);
    char[] result = new char[requiredLength];
    System.arraycopy(converted, 0, result, 0, converted.length);
    return result;
}

From source file:Main.java

private static byte[] getPadded(BigInteger n, int length) {
    byte[] bs = n.toByteArray();
    if (bs.length < length) {
        byte[] tmp = new byte[length];
        System.arraycopy(bs, 0, tmp, length - bs.length, bs.length);
        bs = tmp;//from  www.ja va2s .c o  m
    } else if (bs.length > length) { //BigInteger bigger (probably due to 0 padding)
        byte[] tmp = new byte[length];
        System.arraycopy(bs, bs.length - length, tmp, 0, length);
        bs = tmp;
    }
    return bs;
}