/*
* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2000 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. 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.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
*
Provides various static utility methods.
* * @author Rainer Klute (klute@rainer-klute.de) * @version $Id$ * @since 2002-02-09 */ public class Util { /** *Checks whether two byte arrays a and b * are equal. They are equal
* *if they have the same length and
if for each i with * i >= 0 and * i < a.length holds * a[i] == b[i].
true
if the byte arrays are equal, else
* false
*/
public static boolean equal(final byte[] a, final byte[] b)
{
if (a.length != b.length)
return false;
for (int i = 0; i < a.length; i++)
if (a[i] != b[i])
return false;
return true;
}
/**
* Copies a part of a byte array into another byte array.
* * @param src The source byte array. * @param srcOffset Offset in the source byte array. * @param length The number of bytes to copy. * @param dst The destination byte array. * @param dstOffset Offset in the destination byte array. */ public static void copy(final byte[] src, final int srcOffset, final int length, final byte[] dst, final int dstOffset) { for (int i = 0; i < length; i++) dst[dstOffset + i] = src[srcOffset + i]; } /** *Concatenates the contents of several byte arrays into a * single one.
* * @param byteArrays The byte arrays to be concatened. * @return A new byte array containing the concatenated byte * arrays. */ public static byte[] cat(final byte[][] byteArrays) { int capacity = 0; for (int i = 0; i < byteArrays.length; i++) capacity += byteArrays[i].length; final byte[] result = new byte[capacity]; int r = 0; for (int i = 0; i < byteArrays.length; i++) for (int j = 0; j < byteArrays[i].length; j++) result[r++] = byteArrays[i][j]; return result; } /** *Copies bytes from a source byte array into a new byte * array.
* * @param src Copy from this byte array. * @param offset Start copying here. * @param length Copy this many bytes. * @return The new byte array. Its length is number of copied bytes. */ public static byte[] copy(final byte[] src, final int offset, final int length) { final byte[] result = new byte[length]; copy(src, offset, length, result, 0); return result; } /** *The difference between the Windows epoch (1601-01-01 * 00:00:00) and the Unix epoch (1970-01-01 00:00:00) in * milliseconds: 11644473600000L. (Use your favorite spreadsheet * program to verify the correctness of this value. By the way, * did you notice that you can tell from the epochs which * operating system is the modern one? :-))
*/ public static final long EPOCH_DIFF = 11644473600000L; /** *Converts a Windows FILETIME into a {@link Date}. The Windows * FILETIME structure holds a date and time associated with a * file. The structure identifies a 64-bit integer specifying the * number of 100-nanosecond intervals which have passed since * January 1, 1601. This 64-bit value is split into the two double * words stored in the structure.
* * @param high The higher double word of the FILETIME structure. * @param low The lower double word of the FILETIME structure. * @return The Windows FILETIME as a {@link Date}. */ public static Date filetimeToDate(final int high, final int low) { final long filetime = ((long) high) << 32 | (low & 0xffffffffL); final long ms_since_16010101 = filetime / (1000 * 10); final long ms_since_19700101 = ms_since_16010101 - EPOCH_DIFF; return new Date(ms_since_19700101); } /** *Checks whether two collections are equal. Two collections * C1 and C2 are equal, if the following conditions * are true:
* *For each c1i (element of C1) there * is a c2j (element of C2), and * c1i equals c2j.
For each c2i (element of C2) there * is a c1j (element of C1) and * c2i equals c1j.
true
if the collections are equal, else
* false
.
*/
public static boolean equals(final Collection c1, final Collection c2)
{
final Object[] o1 = c1.toArray();
final Object[] o2 = c2.toArray();
return internalEquals(o1, o2);
}
public static boolean equals(final Object[] c1, final Object[] c2)
{
final Object[] o1 = (Object[]) c1.clone();
final Object[] o2 = (Object[]) c2.clone();
return internalEquals(o1, o2);
}
private static boolean internalEquals(final Object[] o1, final Object[] o2)
{
for (int i1 = 0; i1 < o1.length; i1++)
{
boolean matchFound = false;
for (int i2 = 0; !matchFound && i2 < o1.length; i2++)
if (o1[i1].equals(o2[i2]))
{
matchFound = true;
o2[i2] = null;
}
if (!matchFound)
return false;
}
return true;
}
}