1 /*
   2  * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package java.util.zip;
  27 
  28 import java.util.Date;
  29 import java.util.concurrent.TimeUnit;
  30 
  31 class ZipUtils {
  32 
  33     // used to adjust values between Windows and java epoch
  34     private static final long WINDOWS_EPOCH_IN_MICROSECONDS = -11644473600000000L;
  35 
  36     /**
  37      * Converts Windows time (in microseconds, UTC/GMT) time to Java time.
  38      */
  39     public static final long winToJavaTime(long wtime) {
  40         return TimeUnit.MILLISECONDS.convert(
  41                wtime / 10 + WINDOWS_EPOCH_IN_MICROSECONDS, TimeUnit.MICROSECONDS);
  42     }
  43 
  44     /**
  45      * Converts Java time to Windows time.
  46      */
  47     public static final long javaToWinTime(long time) {
  48         return (TimeUnit.MICROSECONDS.convert(time, TimeUnit.MILLISECONDS)
  49                - WINDOWS_EPOCH_IN_MICROSECONDS) * 10;
  50     }
  51 
  52     /**
  53      * Converts "standard Unix time"(in seconds, UTC/GMT) to Java time
  54      */
  55     public static final long unixToJavaTime(long utime) {
  56         return TimeUnit.MILLISECONDS.convert(utime, TimeUnit.SECONDS);
  57     }
  58 
  59     /**
  60      * Converts Java time to "standard Unix time".
  61      */
  62     public static final long javaToUnixTime(long time) {
  63         return TimeUnit.SECONDS.convert(time, TimeUnit.MILLISECONDS);
  64     }
  65 
  66     /**
  67      * Converts DOS time to Java time (number of milliseconds since epoch).
  68      */
  69     public static long dosToJavaTime(long dtime) {
  70         @SuppressWarnings("deprecation") // Use of date constructor.
  71         Date d = new Date((int)(((dtime >> 25) & 0x7f) + 80),
  72                           (int)(((dtime >> 21) & 0x0f) - 1),
  73                           (int)((dtime >> 16) & 0x1f),
  74                           (int)((dtime >> 11) & 0x1f),
  75                           (int)((dtime >> 5) & 0x3f),
  76                           (int)((dtime << 1) & 0x3e));
  77         return d.getTime();
  78     }
  79 
  80     /**
  81      * Converts Java time to DOS time.
  82      */
  83     @SuppressWarnings("deprecation") // Use of date methods
  84     public static long javaToDosTime(long time) {
  85         Date d = new Date(time);
  86         int year = d.getYear() + 1900;
  87         if (year < 1980) {
  88             return (1 << 21) | (1 << 16);
  89         }
  90         return (year - 1980) << 25 | (d.getMonth() + 1) << 21 |
  91                d.getDate() << 16 | d.getHours() << 11 | d.getMinutes() << 5 |
  92                d.getSeconds() >> 1;
  93     }
  94 
  95 
  96     /**
  97      * Fetches unsigned 16-bit value from byte array at specified offset.
  98      * The bytes are assumed to be in Intel (little-endian) byte order.
  99      */
 100     public static final int get16(byte b[], int off) {
 101         return Byte.toUnsignedInt(b[off]) | (Byte.toUnsignedInt(b[off+1]) << 8);
 102     }
 103 
 104     /**
 105      * Fetches unsigned 32-bit value from byte array at specified offset.
 106      * The bytes are assumed to be in Intel (little-endian) byte order.
 107      */
 108     public static final long get32(byte b[], int off) {
 109         return (get16(b, off) | ((long)get16(b, off+2) << 16)) & 0xffffffffL;
 110     }
 111 
 112     /**
 113      * Fetches signed 64-bit value from byte array at specified offset.
 114      * The bytes are assumed to be in Intel (little-endian) byte order.
 115      */
 116     public static final long get64(byte b[], int off) {
 117         return get32(b, off) | (get32(b, off+4) << 32);
 118     }
 119 
 120 }