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	/*
	* Copyright (c) 2013, 2015, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package java.util.zip;

	import java.nio.file.attribute.FileTime;
	import java.util.Date;
	import java.util.concurrent.TimeUnit;

	class ZipUtils {

	// used to adjust values between Windows and java epoch
	private static final long WINDOWS_EPOCH_IN_MICROSECONDS = -11644473600000000L;

	/**
	* Converts Windows time (in microseconds, UTC/GMT) time to FileTime.
	*/
	public static final FileTime winTimeToFileTime(long wtime) {
	return FileTime.from(wtime / 10 + WINDOWS_EPOCH_IN_MICROSECONDS,
	TimeUnit.MICROSECONDS);
	}

	/**
	* Converts FileTime to Windows time.
	*/
	public static final long fileTimeToWinTime(FileTime ftime) {
	return (ftime.to(TimeUnit.MICROSECONDS) - WINDOWS_EPOCH_IN_MICROSECONDS) * 10;
	}

	/**
	* Converts "standard Unix time"(in seconds, UTC/GMT) to FileTime
	*/
	public static final FileTime unixTimeToFileTime(long utime) {
	return FileTime.from(utime, TimeUnit.SECONDS);
	}

	/**
	* Converts FileTime to "standard Unix time".
	*/
	public static final long fileTimeToUnixTime(FileTime ftime) {
	return ftime.to(TimeUnit.SECONDS);
	}

	/**
	* Converts DOS time to Java time (number of milliseconds since epoch).
	*/
	private static long dosToJavaTime(long dtime) {
	@SuppressWarnings("deprecation") // Use of date constructor.
	Date d = new Date((int)(((dtime >> 25) & 0x7f) + 80),
	(int)(((dtime >> 21) & 0x0f) - 1),
	(int)((dtime >> 16) & 0x1f),
	(int)((dtime >> 11) & 0x1f),
	(int)((dtime >> 5) & 0x3f),
	(int)((dtime << 1) & 0x3e));
	return d.getTime();
	}

	/**
	* Converts extended DOS time to Java time, where up to 1999 milliseconds
	* might be encoded into the upper half of the returned long.
	*
	* @param xdostime the extended DOS time value
	* @return milliseconds since epoch
	*/
	public static long extendedDosToJavaTime(long xdostime) {
	long time = dosToJavaTime(xdostime);
	return time + (xdostime >> 32);
	}

	/**
	* Converts Java time to DOS time.
	*/
	@SuppressWarnings("deprecation") // Use of date methods
	private static long javaToDosTime(long time) {
	Date d = new Date(time);
	int year = d.getYear() + 1900;
	if (year < 1980) {
	return ZipEntry.DOSTIME_BEFORE_1980;
	}
	return (year - 1980) << 25 \| (d.getMonth() + 1) << 21 \|
	d.getDate() << 16 \| d.getHours() << 11 \| d.getMinutes() << 5 \|
	d.getSeconds() >> 1;
	}

	/**
	* Converts Java time to DOS time, encoding any milliseconds lost
	* in the conversion into the upper half of the returned long.
	*
	* @param time milliseconds since epoch
	* @return DOS time with 2s remainder encoded into upper half
	*/
	public static long javaToExtendedDosTime(long time) {
	if (time < 0) {
	return ZipEntry.DOSTIME_BEFORE_1980;
	}
	long dostime = javaToDosTime(time);
	return (dostime != ZipEntry.DOSTIME_BEFORE_1980)
	? dostime + ((time % 2000) << 32)
	: ZipEntry.DOSTIME_BEFORE_1980;
	}

	/**
	* Fetches unsigned 16-bit value from byte array at specified offset.
	* The bytes are assumed to be in Intel (little-endian) byte order.
	*/
	public static final int get16(byte b[], int off) {
	return Byte.toUnsignedInt(b[off]) \| (Byte.toUnsignedInt(b[off+1]) << 8);
	}

	/**
	* Fetches unsigned 32-bit value from byte array at specified offset.
	* The bytes are assumed to be in Intel (little-endian) byte order.
	*/
	public static final long get32(byte b[], int off) {
	return (get16(b, off) \| ((long)get16(b, off+2) << 16)) & 0xffffffffL;
	}

	/**
	* Fetches signed 64-bit value from byte array at specified offset.
	* The bytes are assumed to be in Intel (little-endian) byte order.
	*/
	public static final long get64(byte b[], int off) {
	return get32(b, off) \| (get32(b, off+4) << 32);
	}
	}

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