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The basic runtime tools and interfaces for intarsys components.
/*
* Copyright (c) 2007, intarsys consulting GmbH
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* - Neither the name of intarsys nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
package de.intarsys.tools.collection;
import java.util.Arrays;
import java.util.Random;
public class ByteArrayTools {
public static byte[] concat(byte[] array1, byte[] array2) {
byte[] concat = new byte[array1.length + array2.length];
System.arraycopy(array1, 0, concat, 0, array1.length);
System.arraycopy(array2, 0, concat, array1.length, array2.length);
return concat;
}
/**
* Make a copy of bytes.
*
* @param bytes
* byte[] to be copied
*
* @return A copy of bytes
*/
static public byte[] copy(byte[] bytes) {
byte[] newbuf = new byte[bytes.length];
System.arraycopy(bytes, 0, newbuf, 0, bytes.length);
return newbuf;
}
/**
* Copy length bytes from bytes starting at
* from.
*
* @param bytes
* byte[] to be copied
* @param offset
* starting position to copy from
* @param length
* number of bytes
*
* @return A copy of bytes
*/
static public byte[] copy(byte[] bytes, int offset, int length) {
byte[] newbuf = new byte[length];
System.arraycopy(bytes, offset, newbuf, 0, length);
return newbuf;
}
/**
* A byte array with the defined length, filled with val.
*
* @param length
* @param val
* @return A byte array with the defined length, filled with val.
*/
public static byte[] createBytes(int length, byte val) {
byte[] bytes = new byte[length];
Arrays.fill(bytes, val);
return bytes;
}
/**
* A random byte sequence of length length.
*
* @param length
* @return A random byte sequence of length length.
*/
static public byte[] createRandomBytes(int length) {
Random rand = new Random(System.currentTimeMillis());
byte[] bytes = new byte[length];
rand.nextBytes(bytes);
return bytes;
}
/**
* Checks two arrays or sections thereof for equality. If an array is
* null or it's section is shorter than the compared length,
* false is returned.
*
* @param array1
* @param offset1
* @param array2
* @param offset2
* @param length
* must have a value greater than 0. A value of 0 always returns
* false.
* @return true, if the compared array sections match
*/
public static boolean equals(byte[] array1, int offset1, byte[] array2,
int offset2, int length) {
if (array1 == null || array2 == null) {
return false;
}
if (array1.length - offset1 < length
|| array2.length - offset2 < length) {
return false;
}
if (length == 0) {
return false;
}
for (int i = 0; i < length; i++) {
if (array1[offset1 + i] != array2[offset2 + i]) {
return false;
}
}
return true;
}
/**
* Search index of pattern in source. Algorithm from java.lang.String
*
* @param source
* @param sourceOffset
* @param sourceLen
* @param pattern
* @param patternOffset
* @param patternLen
* @param fromIndex
* @return The index of the first occurrence of pattern or -1.
*/
static public int indexOf(byte[] source, int sourceOffset, int sourceLen,
byte[] pattern, int patternOffset, int patternLen, int fromIndex) {
if (fromIndex >= sourceLen) {
return (patternLen == 0 ? sourceLen : -1);
}
if (fromIndex < 0) {
fromIndex = 0;
}
if (patternLen == 0) {
return fromIndex;
}
byte first = pattern[patternOffset];
int max = sourceOffset + (sourceLen - patternLen);
for (int i = sourceOffset + fromIndex; i <= max; i++) {
/* Look for first byte . */
if (source[i] != first) {
while (++i <= max && source[i] != first) {
;
}
}
/* Found first byte, now look at the rest of v2 */
if (i <= max) {
int j = i + 1;
int end = j + patternLen - 1;
for (int k = patternOffset + 1; j < end
&& source[j] == pattern[k]; j++, k++) {
;
}
if (j == end) {
/* Found whole pattern. */
return i - sourceOffset;
}
}
}
return -1;
}
/**
* true if bytes starts with the byte sequence
* defined in pattern.
*
* @param bytes
* @param pattern
* @return true if bytes starts with the byte
* sequence defined in pattern.
*
*/
static public boolean startsWith(byte[] bytes, byte[] pattern) {
if (bytes == null) {
return false;
}
if (pattern == null) {
return true;
}
int length = pattern.length;
for (int i = 0; i < length; i++) {
if (bytes[i] != pattern[i]) {
return false;
}
}
return true;
}
public static void toBigEndianArray(byte[] bytes, int offset, int value,
int size) {
int bitShift = 0;
for (int i = size - 1; i >= 0; i--) {
bytes[i + offset] = (byte) ((value >>> bitShift) & 0xFF);
bitShift += 8;
}
}
public static byte[] toBigEndianArray(int value, int size) {
byte[] result = new byte[size];
int bitShift = 0;
for (int i = size - 1; i >= 0; i--) {
result[i] = (byte) ((value >>> bitShift) & 0xFF);
bitShift += 8;
}
return result;
}
public static int toBigEndianInteger(byte[] buffer, int offset, int size) {
int value = 0;
for (int i = 0; i < size; i++) {
int bitShift = 8 * (size - i - 1);
value |= (buffer[offset + i] & 0xFF) << bitShift;
}
return value;
}
public static void toLittleEndianArray(byte[] bytes, int offset, int value,
int size) {
for (int i = 0; i < size; i++) {
int bitShift = 8 * i;
bytes[i + offset] = (byte) ((value >>> bitShift) & 0xFF);
}
}
public static void toLittleEndianArray(byte[] bytes, int offset,
long value, int size) {
for (int i = 0; i < size; i++) {
int bitShift = 8 * i;
bytes[i + offset] = (byte) ((value >>> bitShift) & 0xFF);
}
}
public static byte[] toLittleEndianArray(int value, int size) {
byte[] result = new byte[size];
for (int i = 0; i < size; i++) {
int bitShift = 8 * i;
result[i] = (byte) ((value >>> bitShift) & 0xFF);
}
return result;
}
public static byte[] toLittleEndianArray(long value, int size) {
byte[] result = new byte[size];
for (int i = 0; i < size; i++) {
int bitShift = 8 * i;
result[i] = (byte) ((value >>> bitShift) & 0xFF);
}
return result;
}
public static int toLittleEndianInteger(byte[] buffer, int offset, int size) {
int value = 0;
for (int i = 0; i < size; i++) {
int bitShift = 8 * i;
value |= (buffer[offset + i] & 0xFF) << bitShift;
}
return value;
}
public static long toLittleEndianLong(byte[] buffer, int offset, int size) {
long value = 0;
for (int i = 0; i < size; i++) {
int bitShift = 8 * i;
value |= (buffer[offset + i] & 0xFF) << bitShift;
}
return value;
}
}
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