/**********************************************************************************
*
* Copyright (c) 2003, 2004 The Regents of the University of Michigan, Trustees of Indiana University,
* Board of Trustees of the Leland Stanford, Jr., University, and The MIT Corporation
*
* Licensed under the Educational Community License Version 1.0 (the "License");
* By obtaining, using and/or copying this Original Work, you agree that you have read,
* understand, and will comply with the terms and conditions of the Educational Community License.
* You may obtain a copy of the License at:
*
* http://cvs.sakaiproject.org/licenses/license_1_0.html
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
* AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
**********************************************************************************/
/**
* Byte utilities
*/
public class ByteUtils {
/**
* Returns the index in the source array where the last occurrence of the
* specified text (a String, converted to a byte array) is found
*
* @param source
* Byte array to examine
* @param matchString
* String to locate in source
* @return Index of the first matching character (-1 if no match)
*/
public static int lastIndexOf(byte[] source, String matchString) {
return lastIndexOf(source, matchString.getBytes());
}
/**
* Returns the index in the source array where the last occurrence of the
* specified byte pattern is found
*
* @param source
* Byte array to examine
* @param match
* Byte array to locate in source
* @return Index of the last matching character (-1 if no match)
*/
public static int lastIndexOf(byte[] source, byte[] match) {
if (source.length < match.length) {
return -1;
}
for (int i = (source.length - match.length); i >= 0; i--) {
if (startsWith(source, i, match)) {
return i;
}
}
return -1;
}
/**
* Does this byte array begin with match array content?
*
* @param source
* Byte array to examine
* @param match
* Byte array to locate in source
* @return true If the starting bytes are equal
*/
public static boolean startsWith(byte[] source, byte[] match) {
return startsWith(source, 0, match);
}
/**
* Does this byte array begin with match array content?
*
* @param source
* Byte array to examine
* @param offset
* An offset into the source array
* @param match
* Byte array to locate in source
* @return true If the starting bytes are equal
*/
public static boolean startsWith(byte[] source, int offset, byte[] match) {
if (match.length > (source.length - offset)) {
return false;
}
for (int i = 0; i < match.length; i++) {
if (source[offset + i] != match[i]) {
return false;
}
}
return true;
}
/**
* Does the source array equal the match array?
*
* @param source
* Byte array to examine
* @param offset
* An offset into the source array
* @param match
* Byte array to locate in source
* @return true If the two arrays are equal
*/
public static boolean equals(byte[] source, byte[] match) {
if (match.length != source.length) {
return false;
}
return startsWith(source, 0, match);
}
/**
* Copies bytes from the source byte array to the destination array
*
* @param source
* The source array
* @param srcBegin
* Index of the first source byte to copy
* @param srcEnd
* Index after the last source byte to copy
* @param destination
* The destination array
* @param dstBegin
* The starting offset in the destination array
*/
public static void getBytes(byte[] source, int srcBegin, int srcEnd, byte[] destination,
int dstBegin) {
System.arraycopy(source, srcBegin, destination, dstBegin, srcEnd - srcBegin);
}
/**
* Return a new byte array containing a sub-portion of the source array
*
* @param srcBegin
* The beginning index (inclusive)
* @param srcEnd
* The ending index (exclusive)
* @return The new, populated byte array
*/
public static byte[] subbytes(byte[] source, int srcBegin, int srcEnd) {
byte destination[];
destination = new byte[srcEnd - srcBegin];
getBytes(source, srcBegin, srcEnd, destination, 0);
return destination;
}
/**
* Return a new byte array containing a sub-portion of the source array
*
* @param srcBegin
* The beginning index (inclusive)
* @return The new, populated byte array
*/
public static byte[] subbytes(byte[] source, int srcBegin) {
return subbytes(source, srcBegin, source.length);
}
}