| /* |
| * Copyright (C) 2015 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.apkzlib.zip.utils; |
| |
| import com.google.common.base.Verify; |
| |
| import java.util.Calendar; |
| import java.util.Date; |
| |
| /** |
| * Yes. This actually refers to MS-DOS in 2015. That's all I have to say about legacy stuff. |
| */ |
| public class MsDosDateTimeUtils { |
| /** |
| * Utility class: no constructor. |
| */ |
| private MsDosDateTimeUtils() { |
| } |
| |
| /** |
| * Packs java time value into an MS-DOS time value. |
| * |
| * @param time the time value |
| * @return the MS-DOS packed time |
| */ |
| public static int packTime(long time) { |
| Calendar c = Calendar.getInstance(); |
| c.setTime(new Date(time)); |
| |
| int seconds = c.get(Calendar.SECOND); |
| int minutes = c.get(Calendar.MINUTE); |
| int hours = c.get(Calendar.HOUR_OF_DAY); |
| |
| /* |
| * Here is how MS-DOS packs a time value: |
| * 0-4: seconds (divided by 2 because we only have 5 bits = 32 different numbers) |
| * 5-10: minutes (6 bits = 64 possible values) |
| * 11-15: hours (5 bits = 32 possible values) |
| * |
| * source: https://msdn.microsoft.com/en-us/library/windows/desktop/ms724247(v=vs.85).aspx |
| */ |
| return (hours << 11) | (minutes << 5) | (seconds / 2); |
| } |
| |
| /** |
| * Packs the current time value into an MS-DOS time value. |
| * |
| * @return the MS-DOS packed time |
| */ |
| public static int packCurrentTime() { |
| return packTime(new Date().getTime()); |
| } |
| |
| /** |
| * Packs java time value into an MS-DOS date value. |
| * |
| * @param time the time value |
| * @return the MS-DOS packed date |
| */ |
| public static int packDate(long time) { |
| Calendar c = Calendar.getInstance(); |
| c.setTime(new Date(time)); |
| |
| /* |
| * Even MS-DOS used 1 for January. Someone wasn't really thinking when they decided on Java |
| * it would start at 0... |
| */ |
| int day = c.get(Calendar.DAY_OF_MONTH); |
| int month = c.get(Calendar.MONTH) + 1; |
| |
| /* |
| * MS-DOS counts years starting from 1980. Since its launch date was in 81, it was obviously |
| * not necessary to talk about dates earlier than that. |
| */ |
| int year = c.get(Calendar.YEAR) - 1980; |
| Verify.verify(year >= 0 && year < 128); |
| |
| /* |
| * Here is how MS-DOS packs a date value: |
| * 0-4: day (5 bits = 32 values) |
| * 5-8: month (4 bits = 16 values) |
| * 9-15: year (7 bits = 128 values) |
| * |
| * source: https://msdn.microsoft.com/en-us/library/windows/desktop/ms724247(v=vs.85).aspx |
| */ |
| return (year << 9) | (month << 5) | day; |
| } |
| |
| /** |
| * Packs the current time value into an MS-DOS date value. |
| * |
| * @return the MS-DOS packed date |
| */ |
| public static int packCurrentDate() { |
| return packDate(new Date().getTime()); |
| } |
| } |