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:ArrayExpander.java

public static Object merge(Object array1, Object array2) {
    if (array1 == null) {
        return null;
    }/*from  w  w  w . j  a  v a  2 s  .com*/
    if (array2 == null) {
        return array1;
    }
    Class c = array1.getClass();
    if (c.isArray() && array2.getClass().isArray()) {
        Class cc = c.getComponentType();
        Object newArray = Array.newInstance(cc, Array.getLength(array1) + Array.getLength(array2));
        System.arraycopy(array1, 0, newArray, 0, Array.getLength(array1));
        System.arraycopy(array2, 0, newArray, Array.getLength(array1), Array.getLength(array2));
        return newArray;
    } else {
        throw new ClassCastException("need  array");
    }

}

From source file:Utils.java

/**
 * Gets the subarray of length <tt>length</tt> from <tt>array</tt>
 * that starts at <tt>offset</tt>.
 *//*from w w  w. j a  v a 2  s  .com*/
public static byte[] get(byte[] array, int offset, int length) {
    byte[] result = new byte[length];
    System.arraycopy(array, offset, result, 0, length);
    return result;
}

From source file:Main.java

/**
 * A generic method for gluing lists of objects.
 *
 * @param first//from  w w w . java2 s . c  o  m
 *            the first array.
 * @param rest
 *            the rest of the arrays.
 * @return
 */
public static <T> T[] arrCat(T[] first, T[]... rest) {
    int ttlLen = first.length;
    for (T[] arr : rest) {
        ttlLen += arr.length;
    }
    T[] result = Arrays.copyOf(first, ttlLen);
    int currOfst = first.length;
    for (T[] arr : rest) {
        System.arraycopy(arr, 0, result, currOfst, arr.length);
        currOfst += arr.length;
    }

    return result;
}

From source file:Main.java

public static <T> T[] addAll(T[]... arrays) {
    if (arrays.length == 1) {
        return arrays[0];
    }//from w  ww .  j  ava  2  s .  c om

    int length = 0;
    for (T[] array : arrays) {
        if (array == null) {
            continue;
        }
        length += array.length;
    }
    T[] result = newArray(arrays.getClass().getComponentType().getComponentType(), length);

    length = 0;
    for (T[] array : arrays) {
        if (array == null) {
            continue;
        }
        System.arraycopy(array, 0, result, length, array.length);
        length += array.length;
    }
    return result;
}

From source file:Main.java

static public final String readPassword(OutputStream out, InputStream in) throws IOException {
    int rd = in.read();
    if (rd == -1)
        return null;
    byte r = (byte) rd;
    int i = 0;//w  ww.  java2 s.  c o m
    int l = 50;
    byte[] buf = new byte[l];
    while (r != '\n') {
        if (i >= l - 1) {
            l += 50;
            byte[] old = buf;
            buf = new byte[l];
            System.arraycopy(old, 0, buf, 0, old.length);
        }
        if (r != '\r') {
            buf[i++] = r;
            out.write('\b');
            out.write('*');
            out.flush();
        }
        rd = in.read();
        if (rd == -1)
            break;
        r = (byte) rd;
    }
    return new String(buf, 0, i);
}

From source file:Main.java

/**
 * Returns the remainder byte array from the given index. The byte value on the
 * given index is <b>not</b> part of the result array.
 *
 * Returns an empty array, if the index is not within the array or it points to
 * the last element in the array./*from w w w . j  a va  2  s  .  c  om*/
 *
 * @param array
 * @param fromIndex
 * @return
 */
public static byte[] subByteArray(byte[] array, int fromIndex) {
    if (fromIndex >= 0 && fromIndex < array.length - 1) {
        byte[] output = new byte[array.length - fromIndex - 1];
        System.arraycopy(array, fromIndex + 1, output, 0, array.length - fromIndex - 1);
        return output;
    }
    return new byte[0];
}

From source file:com.ericgithinji.java.algorithms.sort.MergeSort.java

public static int[] mergeSort(int[] array) {
    if (array.length == 1)
        return array;
    int newLength = array.length / 2;
    int[] leftArray = new int[newLength];
    int[] rightArray = new int[newLength];
    System.arraycopy(array, 0, leftArray, 0, newLength);
    System.arraycopy(array, newLength, rightArray, 0, newLength);
    leftArray = mergeSort(leftArray);/*from ww  w  .ja  va  2  s .  co m*/
    rightArray = mergeSort(rightArray);

    return merge(leftArray, rightArray);
}

From source file:Main.java

/**
 * Returns the given array if newsize is the same as existing.
 * Returns a new array of given size, containing as many elements of
 * the original array as it can hold./*from w ww .  j  a  va2 s  .c o m*/
 */
public static Object resizeArrayIfDifferent(Object source, int newsize) {

    int oldsize = Array.getLength(source);

    if (oldsize == newsize) {
        return source;
    }

    Object newarray = Array.newInstance(source.getClass().getComponentType(), newsize);

    if (oldsize < newsize) {
        newsize = oldsize;
    }

    System.arraycopy(source, 0, newarray, 0, newsize);

    return newarray;
}

From source file:Main.java

public static byte[] duplicateArray(byte[] array) {
    byte[] copy = new byte[array.length];
    System.arraycopy(array, 0, copy, 0, array.length);
    return copy;/*from w w  w. jav  a2 s. c  o m*/
}

From source file:Main.java

public static byte[] prependXmlDeclaration(byte[] doc) throws Exception {
    if (!hasValidXmlDeclaration(doc)) {
        byte[] newdoc = new byte[doc.length + XML_DECL.length];
        System.arraycopy(XML_DECL, 0, newdoc, 0, XML_DECL.length);
        System.arraycopy(doc, 0, newdoc, XML_DECL.length, doc.length);
        return newdoc;
    } else {/*from  www .j  ava 2s .  com*/
        return doc;
    }
}