Java tutorial
/* * Copyright (C) 2006 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 android.text.format; import android.annotation.UnsupportedAppUsage; import android.content.Context; import android.content.res.Configuration; import android.content.res.Resources; import android.icu.text.MeasureFormat; import android.icu.text.MeasureFormat.FormatWidth; import android.icu.util.Measure; import android.icu.util.MeasureUnit; import com.android.internal.R; import libcore.icu.DateIntervalFormat; import libcore.icu.LocaleData; import libcore.icu.RelativeDateTimeFormatter; import java.io.IOException; import java.util.Calendar; import java.util.Date; import java.util.Formatter; import java.util.GregorianCalendar; import java.util.Locale; import java.util.TimeZone; /** * This class contains various date-related utilities for creating text for things like * elapsed time and date ranges, strings for days of the week and months, and AM/PM text etc. */ public class DateUtils { private static final Object sLock = new Object(); private static Configuration sLastConfig; private static String sElapsedFormatMMSS; private static String sElapsedFormatHMMSS; public static final long SECOND_IN_MILLIS = 1000; public static final long MINUTE_IN_MILLIS = SECOND_IN_MILLIS * 60; public static final long HOUR_IN_MILLIS = MINUTE_IN_MILLIS * 60; public static final long DAY_IN_MILLIS = HOUR_IN_MILLIS * 24; public static final long WEEK_IN_MILLIS = DAY_IN_MILLIS * 7; /** * This constant is actually the length of 364 days, not of a year! */ public static final long YEAR_IN_MILLIS = WEEK_IN_MILLIS * 52; // The following FORMAT_* symbols are used for specifying the format of // dates and times in the formatDateRange method. public static final int FORMAT_SHOW_TIME = 0x00001; public static final int FORMAT_SHOW_WEEKDAY = 0x00002; public static final int FORMAT_SHOW_YEAR = 0x00004; public static final int FORMAT_NO_YEAR = 0x00008; public static final int FORMAT_SHOW_DATE = 0x00010; public static final int FORMAT_NO_MONTH_DAY = 0x00020; @Deprecated public static final int FORMAT_12HOUR = 0x00040; @Deprecated public static final int FORMAT_24HOUR = 0x00080; @Deprecated public static final int FORMAT_CAP_AMPM = 0x00100; public static final int FORMAT_NO_NOON = 0x00200; @Deprecated public static final int FORMAT_CAP_NOON = 0x00400; public static final int FORMAT_NO_MIDNIGHT = 0x00800; @Deprecated public static final int FORMAT_CAP_MIDNIGHT = 0x01000; /** * @deprecated Use * {@link #formatDateRange(Context, Formatter, long, long, int, String) formatDateRange} * and pass in {@link Time#TIMEZONE_UTC Time.TIMEZONE_UTC} for the timeZone instead. */ @Deprecated public static final int FORMAT_UTC = 0x02000; public static final int FORMAT_ABBREV_TIME = 0x04000; public static final int FORMAT_ABBREV_WEEKDAY = 0x08000; public static final int FORMAT_ABBREV_MONTH = 0x10000; public static final int FORMAT_NUMERIC_DATE = 0x20000; public static final int FORMAT_ABBREV_RELATIVE = 0x40000; public static final int FORMAT_ABBREV_ALL = 0x80000; @Deprecated public static final int FORMAT_CAP_NOON_MIDNIGHT = (FORMAT_CAP_NOON | FORMAT_CAP_MIDNIGHT); @Deprecated public static final int FORMAT_NO_NOON_MIDNIGHT = (FORMAT_NO_NOON | FORMAT_NO_MIDNIGHT); // Date and time format strings that are constant and don't need to be // translated. /** * This is not actually the preferred 24-hour date format in all locales. * @deprecated Use {@link java.text.SimpleDateFormat} instead. */ @Deprecated public static final String HOUR_MINUTE_24 = "%H:%M"; public static final String MONTH_FORMAT = "%B"; /** * This is not actually a useful month name in all locales. * @deprecated Use {@link java.text.SimpleDateFormat} instead. */ @Deprecated public static final String ABBREV_MONTH_FORMAT = "%b"; public static final String NUMERIC_MONTH_FORMAT = "%m"; public static final String MONTH_DAY_FORMAT = "%-d"; public static final String YEAR_FORMAT = "%Y"; public static final String YEAR_FORMAT_TWO_DIGITS = "%g"; public static final String WEEKDAY_FORMAT = "%A"; public static final String ABBREV_WEEKDAY_FORMAT = "%a"; /** @deprecated Do not use. */ @Deprecated public static final int[] sameYearTable = null; /** @deprecated Do not use. */ @Deprecated public static final int[] sameMonthTable = null; /** * Request the full spelled-out name. For use with the 'abbrev' parameter of * {@link #getDayOfWeekString} and {@link #getMonthString}. * * @more <p> * e.g. "Sunday" or "January" * @deprecated Use {@link java.text.SimpleDateFormat} instead. */ @Deprecated public static final int LENGTH_LONG = 10; /** * Request an abbreviated version of the name. For use with the 'abbrev' * parameter of {@link #getDayOfWeekString} and {@link #getMonthString}. * * @more <p> * e.g. "Sun" or "Jan" * @deprecated Use {@link java.text.SimpleDateFormat} instead. */ @Deprecated public static final int LENGTH_MEDIUM = 20; /** * Request a shorter abbreviated version of the name. * For use with the 'abbrev' parameter of {@link #getDayOfWeekString} and {@link #getMonthString}. * @more * <p>e.g. "Su" or "Jan" * <p>In most languages, the results returned for LENGTH_SHORT will be the same as * the results returned for {@link #LENGTH_MEDIUM}. * @deprecated Use {@link java.text.SimpleDateFormat} instead. */ @Deprecated public static final int LENGTH_SHORT = 30; /** * Request an even shorter abbreviated version of the name. * Do not use this. Currently this will always return the same result * as {@link #LENGTH_SHORT}. * @deprecated Use {@link java.text.SimpleDateFormat} instead. */ @Deprecated public static final int LENGTH_SHORTER = 40; /** * Request an even shorter abbreviated version of the name. * For use with the 'abbrev' parameter of {@link #getDayOfWeekString} and {@link #getMonthString}. * @more * <p>e.g. "S", "T", "T" or "J" * <p>In some languages, the results returned for LENGTH_SHORTEST will be the same as * the results returned for {@link #LENGTH_SHORT}. * @deprecated Use {@link java.text.SimpleDateFormat} instead. */ @Deprecated public static final int LENGTH_SHORTEST = 50; /** * Return a string for the day of the week. * @param dayOfWeek One of {@link Calendar#SUNDAY Calendar.SUNDAY}, * {@link Calendar#MONDAY Calendar.MONDAY}, etc. * @param abbrev One of {@link #LENGTH_LONG}, {@link #LENGTH_SHORT}, * {@link #LENGTH_MEDIUM}, or {@link #LENGTH_SHORTEST}. * Note that in most languages, {@link #LENGTH_SHORT} * will return the same as {@link #LENGTH_MEDIUM}. * Undefined lengths will return {@link #LENGTH_MEDIUM} * but may return something different in the future. * @throws IndexOutOfBoundsException if the dayOfWeek is out of bounds. * @deprecated Use {@link java.text.SimpleDateFormat} instead. */ @Deprecated public static String getDayOfWeekString(int dayOfWeek, int abbrev) { LocaleData d = LocaleData.get(Locale.getDefault()); String[] names; switch (abbrev) { case LENGTH_LONG: names = d.longWeekdayNames; break; case LENGTH_MEDIUM: names = d.shortWeekdayNames; break; case LENGTH_SHORT: names = d.shortWeekdayNames; break; // TODO case LENGTH_SHORTER: names = d.shortWeekdayNames; break; // TODO case LENGTH_SHORTEST: names = d.tinyWeekdayNames; break; default: names = d.shortWeekdayNames; break; } return names[dayOfWeek]; } /** * Return a localized string for AM or PM. * @param ampm Either {@link Calendar#AM Calendar.AM} or {@link Calendar#PM Calendar.PM}. * @throws IndexOutOfBoundsException if the ampm is out of bounds. * @return Localized version of "AM" or "PM". * @deprecated Use {@link java.text.SimpleDateFormat} instead. */ @Deprecated public static String getAMPMString(int ampm) { return LocaleData.get(Locale.getDefault()).amPm[ampm - Calendar.AM]; } /** * Return a localized string for the month of the year. * @param month One of {@link Calendar#JANUARY Calendar.JANUARY}, * {@link Calendar#FEBRUARY Calendar.FEBRUARY}, etc. * @param abbrev One of {@link #LENGTH_LONG}, {@link #LENGTH_MEDIUM}, * or {@link #LENGTH_SHORTEST}. * Undefined lengths will return {@link #LENGTH_MEDIUM} * but may return something different in the future. * @return Localized month of the year. * @deprecated Use {@link java.text.SimpleDateFormat} instead. */ @Deprecated public static String getMonthString(int month, int abbrev) { LocaleData d = LocaleData.get(Locale.getDefault()); String[] names; switch (abbrev) { case LENGTH_LONG: names = d.longMonthNames; break; case LENGTH_MEDIUM: names = d.shortMonthNames; break; case LENGTH_SHORT: names = d.shortMonthNames; break; case LENGTH_SHORTER: names = d.shortMonthNames; break; case LENGTH_SHORTEST: names = d.tinyMonthNames; break; default: names = d.shortMonthNames; break; } return names[month]; } /** * Returns a string describing the elapsed time since startTime. * <p> * The minimum timespan to report is set to {@link #MINUTE_IN_MILLIS}. * @param startTime some time in the past. * @return a String object containing the elapsed time. * @see #getRelativeTimeSpanString(long, long, long) */ public static CharSequence getRelativeTimeSpanString(long startTime) { return getRelativeTimeSpanString(startTime, System.currentTimeMillis(), MINUTE_IN_MILLIS); } /** * Returns a string describing 'time' as a time relative to 'now'. * <p> * Time spans in the past are formatted like "42 minutes ago". * Time spans in the future are formatted like "In 42 minutes". * * @param time the time to describe, in milliseconds * @param now the current time in milliseconds * @param minResolution the minimum timespan to report. For example, a time 3 seconds in the * past will be reported as "0 minutes ago" if this is set to MINUTE_IN_MILLIS. Pass one of * 0, MINUTE_IN_MILLIS, HOUR_IN_MILLIS, DAY_IN_MILLIS, WEEK_IN_MILLIS */ public static CharSequence getRelativeTimeSpanString(long time, long now, long minResolution) { int flags = FORMAT_SHOW_DATE | FORMAT_SHOW_YEAR | FORMAT_ABBREV_MONTH; return getRelativeTimeSpanString(time, now, minResolution, flags); } /** * Returns a string describing 'time' as a time relative to 'now'. * <p> * Time spans in the past are formatted like "42 minutes ago". Time spans in * the future are formatted like "In 42 minutes". * <p> * Can use {@link #FORMAT_ABBREV_RELATIVE} flag to use abbreviated relative * times, like "42 mins ago". * * @param time the time to describe, in milliseconds * @param now the current time in milliseconds * @param minResolution the minimum timespan to report. For example, a time * 3 seconds in the past will be reported as "0 minutes ago" if * this is set to MINUTE_IN_MILLIS. Pass one of 0, * MINUTE_IN_MILLIS, HOUR_IN_MILLIS, DAY_IN_MILLIS, * WEEK_IN_MILLIS * @param flags a bit mask of formatting options, such as * {@link #FORMAT_NUMERIC_DATE} or * {@link #FORMAT_ABBREV_RELATIVE} */ public static CharSequence getRelativeTimeSpanString(long time, long now, long minResolution, int flags) { return RelativeDateTimeFormatter.getRelativeTimeSpanString(Locale.getDefault(), TimeZone.getDefault(), time, now, minResolution, flags); } /** * Return string describing the elapsed time since startTime formatted like * "[relative time/date], [time]". * <p> * Example output strings for the US date format. * <ul> * <li>3 min. ago, 10:15 AM</li> * <li>Yesterday, 12:20 PM</li> * <li>Dec 12, 4:12 AM</li> * <li>11/14/2007, 8:20 AM</li> * </ul> * * @param time some time in the past. * @param minResolution the minimum elapsed time (in milliseconds) to report * when showing relative times. For example, a time 3 seconds in * the past will be reported as "0 minutes ago" if this is set to * {@link #MINUTE_IN_MILLIS}. * @param transitionResolution the elapsed time (in milliseconds) at which * to stop reporting relative measurements. Elapsed times greater * than this resolution will default to normal date formatting. * For example, will transition from "7 days ago" to "Dec 12" * when using {@link #WEEK_IN_MILLIS}. */ public static CharSequence getRelativeDateTimeString(Context c, long time, long minResolution, long transitionResolution, int flags) { // Same reason as in formatDateRange() to explicitly indicate 12- or 24-hour format. if ((flags & (FORMAT_SHOW_TIME | FORMAT_12HOUR | FORMAT_24HOUR)) == FORMAT_SHOW_TIME) { flags |= DateFormat.is24HourFormat(c) ? FORMAT_24HOUR : FORMAT_12HOUR; } return RelativeDateTimeFormatter.getRelativeDateTimeString(Locale.getDefault(), TimeZone.getDefault(), time, System.currentTimeMillis(), minResolution, transitionResolution, flags); } private static void initFormatStrings() { synchronized (sLock) { initFormatStringsLocked(); } } private static void initFormatStringsLocked() { Resources r = Resources.getSystem(); Configuration cfg = r.getConfiguration(); if (sLastConfig == null || !sLastConfig.equals(cfg)) { sLastConfig = cfg; sElapsedFormatMMSS = r.getString(com.android.internal.R.string.elapsed_time_short_format_mm_ss); sElapsedFormatHMMSS = r.getString(com.android.internal.R.string.elapsed_time_short_format_h_mm_ss); } } /** * Returns the given duration in a human-friendly format. For example, * "4 minutes" or "1 second". Returns only the largest meaningful unit of time, * from seconds up to hours. * * @hide */ @UnsupportedAppUsage public static CharSequence formatDuration(long millis) { return formatDuration(millis, LENGTH_LONG); } /** * Returns the given duration in a human-friendly format. For example, * "4 minutes" or "1 second". Returns only the largest meaningful unit of time, * from seconds up to hours. * <p> * You can use abbrev to specify a preference for abbreviations (but note that some * locales may not have abbreviations). Use LENGTH_LONG for the full spelling (e.g. "2 hours"), * LENGTH_SHORT for the abbreviated spelling if available (e.g. "2 hr"), and LENGTH_SHORTEST for * the briefest form available (e.g. "2h"). * @hide */ @UnsupportedAppUsage public static CharSequence formatDuration(long millis, int abbrev) { final FormatWidth width; switch (abbrev) { case LENGTH_LONG: width = FormatWidth.WIDE; break; case LENGTH_SHORT: case LENGTH_SHORTER: case LENGTH_MEDIUM: width = FormatWidth.SHORT; break; case LENGTH_SHORTEST: width = FormatWidth.NARROW; break; default: width = FormatWidth.WIDE; } final MeasureFormat formatter = MeasureFormat.getInstance(Locale.getDefault(), width); if (millis >= HOUR_IN_MILLIS) { final int hours = (int) ((millis + 1800000) / HOUR_IN_MILLIS); return formatter.format(new Measure(hours, MeasureUnit.HOUR)); } else if (millis >= MINUTE_IN_MILLIS) { final int minutes = (int) ((millis + 30000) / MINUTE_IN_MILLIS); return formatter.format(new Measure(minutes, MeasureUnit.MINUTE)); } else { final int seconds = (int) ((millis + 500) / SECOND_IN_MILLIS); return formatter.format(new Measure(seconds, MeasureUnit.SECOND)); } } /** * Formats an elapsed time in the form "MM:SS" or "H:MM:SS" * for display on the call-in-progress screen. * @param elapsedSeconds the elapsed time in seconds. */ public static String formatElapsedTime(long elapsedSeconds) { return formatElapsedTime(null, elapsedSeconds); } /** * Formats an elapsed time in a format like "MM:SS" or "H:MM:SS" (using a form * suited to the current locale), similar to that used on the call-in-progress * screen. * * @param recycle {@link StringBuilder} to recycle, or null to use a temporary one. * @param elapsedSeconds the elapsed time in seconds. */ public static String formatElapsedTime(StringBuilder recycle, long elapsedSeconds) { // Break the elapsed seconds into hours, minutes, and seconds. long hours = 0; long minutes = 0; long seconds = 0; if (elapsedSeconds >= 3600) { hours = elapsedSeconds / 3600; elapsedSeconds -= hours * 3600; } if (elapsedSeconds >= 60) { minutes = elapsedSeconds / 60; elapsedSeconds -= minutes * 60; } seconds = elapsedSeconds; // Create a StringBuilder if we weren't given one to recycle. // TODO: if we cared, we could have a thread-local temporary StringBuilder. StringBuilder sb = recycle; if (sb == null) { sb = new StringBuilder(8); } else { sb.setLength(0); } // Format the broken-down time in a locale-appropriate way. // TODO: use icu4c when http://unicode.org/cldr/trac/ticket/3407 is fixed. Formatter f = new Formatter(sb, Locale.getDefault()); initFormatStrings(); if (hours > 0) { return f.format(sElapsedFormatHMMSS, hours, minutes, seconds).toString(); } else { return f.format(sElapsedFormatMMSS, minutes, seconds).toString(); } } /** * Format a date / time such that if the then is on the same day as now, it shows * just the time and if it's a different day, it shows just the date. * * <p>The parameters dateFormat and timeFormat should each be one of * {@link java.text.DateFormat#DEFAULT}, * {@link java.text.DateFormat#FULL}, * {@link java.text.DateFormat#LONG}, * {@link java.text.DateFormat#MEDIUM} * or * {@link java.text.DateFormat#SHORT} * * @param then the date to format * @param now the base time * @param dateStyle how to format the date portion. * @param timeStyle how to format the time portion. */ public static final CharSequence formatSameDayTime(long then, long now, int dateStyle, int timeStyle) { Calendar thenCal = new GregorianCalendar(); thenCal.setTimeInMillis(then); Date thenDate = thenCal.getTime(); Calendar nowCal = new GregorianCalendar(); nowCal.setTimeInMillis(now); java.text.DateFormat f; if (thenCal.get(Calendar.YEAR) == nowCal.get(Calendar.YEAR) && thenCal.get(Calendar.MONTH) == nowCal.get(Calendar.MONTH) && thenCal.get(Calendar.DAY_OF_MONTH) == nowCal.get(Calendar.DAY_OF_MONTH)) { f = java.text.DateFormat.getTimeInstance(timeStyle); } else { f = java.text.DateFormat.getDateInstance(dateStyle); } return f.format(thenDate); } /** * @return true if the supplied when is today else false */ public static boolean isToday(long when) { Time time = new Time(); time.set(when); int thenYear = time.year; int thenMonth = time.month; int thenMonthDay = time.monthDay; time.set(System.currentTimeMillis()); return (thenYear == time.year) && (thenMonth == time.month) && (thenMonthDay == time.monthDay); } /** * Formats a date or a time range according to the local conventions. * <p> * Note that this is a convenience method. Using it involves creating an * internal {@link java.util.Formatter} instance on-the-fly, which is * somewhat costly in terms of memory and time. This is probably acceptable * if you use the method only rarely, but if you rely on it for formatting a * large number of dates, consider creating and reusing your own * {@link java.util.Formatter} instance and use the version of * {@link #formatDateRange(Context, long, long, int) formatDateRange} * that takes a {@link java.util.Formatter}. * * @param context the context is required only if the time is shown * @param startMillis the start time in UTC milliseconds * @param endMillis the end time in UTC milliseconds * @param flags a bit mask of options See * {@link #formatDateRange(Context, Formatter, long, long, int, String) formatDateRange} * @return a string containing the formatted date/time range. */ public static String formatDateRange(Context context, long startMillis, long endMillis, int flags) { Formatter f = new Formatter(new StringBuilder(50), Locale.getDefault()); return formatDateRange(context, f, startMillis, endMillis, flags).toString(); } /** * Formats a date or a time range according to the local conventions. * <p> * Note that this is a convenience method for formatting the date or * time range in the local time zone. If you want to specify the time * zone please use * {@link #formatDateRange(Context, Formatter, long, long, int, String) formatDateRange}. * * @param context the context is required only if the time is shown * @param formatter the Formatter used for formatting the date range. * Note: be sure to call setLength(0) on StringBuilder passed to * the Formatter constructor unless you want the results to accumulate. * @param startMillis the start time in UTC milliseconds * @param endMillis the end time in UTC milliseconds * @param flags a bit mask of options See * {@link #formatDateRange(Context, Formatter, long, long, int, String) formatDateRange} * @return a string containing the formatted date/time range. */ public static Formatter formatDateRange(Context context, Formatter formatter, long startMillis, long endMillis, int flags) { return formatDateRange(context, formatter, startMillis, endMillis, flags, null); } /** * Formats a date or a time range according to the local conventions. * * <p> * Example output strings (date formats in these examples are shown using * the US date format convention but that may change depending on the * local settings): * <ul> * <li>10:15am</li> * <li>3:00pm - 4:00pm</li> * <li>3pm - 4pm</li> * <li>3PM - 4PM</li> * <li>08:00 - 17:00</li> * <li>Oct 9</li> * <li>Tue, Oct 9</li> * <li>October 9, 2007</li> * <li>Oct 9 - 10</li> * <li>Oct 9 - 10, 2007</li> * <li>Oct 28 - Nov 3, 2007</li> * <li>Dec 31, 2007 - Jan 1, 2008</li> * <li>Oct 9, 8:00am - Oct 10, 5:00pm</li> * <li>12/31/2007 - 01/01/2008</li> * </ul> * * <p> * The flags argument is a bitmask of options from the following list: * * <ul> * <li>FORMAT_SHOW_TIME</li> * <li>FORMAT_SHOW_WEEKDAY</li> * <li>FORMAT_SHOW_YEAR</li> * <li>FORMAT_SHOW_DATE</li> * <li>FORMAT_NO_MONTH_DAY</li> * <li>FORMAT_12HOUR</li> * <li>FORMAT_24HOUR</li> * <li>FORMAT_CAP_AMPM</li> * <li>FORMAT_NO_NOON</li> * <li>FORMAT_CAP_NOON</li> * <li>FORMAT_NO_MIDNIGHT</li> * <li>FORMAT_CAP_MIDNIGHT</li> * <li>FORMAT_UTC</li> * <li>FORMAT_ABBREV_TIME</li> * <li>FORMAT_ABBREV_WEEKDAY</li> * <li>FORMAT_ABBREV_MONTH</li> * <li>FORMAT_ABBREV_ALL</li> * <li>FORMAT_NUMERIC_DATE</li> * </ul> * * <p> * If FORMAT_SHOW_TIME is set, the time is shown as part of the date range. * If the start and end time are the same, then just the start time is * shown. * * <p> * If FORMAT_SHOW_WEEKDAY is set, then the weekday is shown. * * <p> * If FORMAT_SHOW_YEAR is set, then the year is always shown. * If FORMAT_SHOW_YEAR is not set, then the year * is shown only if it is different from the current year, or if the start * and end dates fall on different years. * * <p> * Normally the date is shown unless the start and end day are the same. * If FORMAT_SHOW_DATE is set, then the date is always shown, even for * same day ranges. * * <p> * If FORMAT_NO_MONTH_DAY is set, then if the date is shown, just the * month name will be shown, not the day of the month. For example, * "January, 2008" instead of "January 6 - 12, 2008". * * <p> * If FORMAT_CAP_AMPM is set and 12-hour time is used, then the "AM" * and "PM" are capitalized. You should not use this flag * because in some locales these terms cannot be capitalized, and in * many others it doesn't make sense to do so even though it is possible. * * <p> * If FORMAT_NO_NOON is set and 12-hour time is used, then "12pm" is * shown instead of "noon". * * <p> * If FORMAT_CAP_NOON is set and 12-hour time is used, then "Noon" is * shown instead of "noon". You should probably not use this flag * because in many locales it will not make sense to capitalize * the term. * * <p> * If FORMAT_NO_MIDNIGHT is set and 12-hour time is used, then "12am" is * shown instead of "midnight". * * <p> * If FORMAT_CAP_MIDNIGHT is set and 12-hour time is used, then "Midnight" * is shown instead of "midnight". You should probably not use this * flag because in many locales it will not make sense to capitalize * the term. * * <p> * If FORMAT_12HOUR is set and the time is shown, then the time is * shown in the 12-hour time format. You should not normally set this. * Instead, let the time format be chosen automatically according to the * system settings. If both FORMAT_12HOUR and FORMAT_24HOUR are set, then * FORMAT_24HOUR takes precedence. * * <p> * If FORMAT_24HOUR is set and the time is shown, then the time is * shown in the 24-hour time format. You should not normally set this. * Instead, let the time format be chosen automatically according to the * system settings. If both FORMAT_12HOUR and FORMAT_24HOUR are set, then * FORMAT_24HOUR takes precedence. * * <p> * If FORMAT_UTC is set, then the UTC time zone is used for the start * and end milliseconds unless a time zone is specified. If a time zone * is specified it will be used regardless of the FORMAT_UTC flag. * * <p> * If FORMAT_ABBREV_TIME is set and 12-hour time format is used, then the * start and end times (if shown) are abbreviated by not showing the minutes * if they are zero. For example, instead of "3:00pm" the time would be * abbreviated to "3pm". * * <p> * If FORMAT_ABBREV_WEEKDAY is set, then the weekday (if shown) is * abbreviated to a 3-letter string. * * <p> * If FORMAT_ABBREV_MONTH is set, then the month (if shown) is abbreviated * to a 3-letter string. * * <p> * If FORMAT_ABBREV_ALL is set, then the weekday and the month (if shown) * are abbreviated to 3-letter strings. * * <p> * If FORMAT_NUMERIC_DATE is set, then the date is shown in numeric format * instead of using the name of the month. For example, "12/31/2008" * instead of "December 31, 2008". * * <p> * If the end date ends at 12:00am at the beginning of a day, it is * formatted as the end of the previous day in two scenarios: * <ul> * <li>For single day events. This results in "8pm - midnight" instead of * "Nov 10, 8pm - Nov 11, 12am".</li> * <li>When the time is not displayed. This results in "Nov 10 - 11" for * an event with a start date of Nov 10 and an end date of Nov 12 at * 00:00.</li> * </ul> * * @param context the context is required only if the time is shown * @param formatter the Formatter used for formatting the date range. * Note: be sure to call setLength(0) on StringBuilder passed to * the Formatter constructor unless you want the results to accumulate. * @param startMillis the start time in UTC milliseconds * @param endMillis the end time in UTC milliseconds * @param flags a bit mask of options * @param timeZone the time zone to compute the string in. Use null for local * or if the FORMAT_UTC flag is being used. * * @return the formatter with the formatted date/time range appended to the string buffer. */ public static Formatter formatDateRange(Context context, Formatter formatter, long startMillis, long endMillis, int flags, String timeZone) { // If we're being asked to format a time without being explicitly told whether to use // the 12- or 24-hour clock, icu4c will fall back to the locale's preferred 12/24 format, // but we want to fall back to the user's preference. if ((flags & (FORMAT_SHOW_TIME | FORMAT_12HOUR | FORMAT_24HOUR)) == FORMAT_SHOW_TIME) { flags |= DateFormat.is24HourFormat(context) ? FORMAT_24HOUR : FORMAT_12HOUR; } String range = DateIntervalFormat.formatDateRange(startMillis, endMillis, flags, timeZone); try { formatter.out().append(range); } catch (IOException impossible) { throw new AssertionError(impossible); } return formatter; } /** * Formats a date or a time according to the local conventions. There are * lots of options that allow the caller to control, for example, if the * time is shown, if the day of the week is shown, if the month name is * abbreviated, if noon is shown instead of 12pm, and so on. For the * complete list of options, see the documentation for * {@link #formatDateRange}. * <p> * Example output strings (date formats in these examples are shown using * the US date format convention but that may change depending on the * local settings): * <ul> * <li>10:15am</li> * <li>3:00pm</li> * <li>3pm</li> * <li>3PM</li> * <li>08:00</li> * <li>17:00</li> * <li>noon</li> * <li>Noon</li> * <li>midnight</li> * <li>Midnight</li> * <li>Oct 31</li> * <li>Oct 31, 2007</li> * <li>October 31, 2007</li> * <li>10am, Oct 31</li> * <li>17:00, Oct 31</li> * <li>Wed</li> * <li>Wednesday</li> * <li>10am, Wed, Oct 31</li> * <li>Wed, Oct 31</li> * <li>Wednesday, Oct 31</li> * <li>Wed, Oct 31, 2007</li> * <li>Wed, October 31</li> * <li>10/31/2007</li> * </ul> * * @param context the context is required only if the time is shown * @param millis a point in time in UTC milliseconds * @param flags a bit mask of formatting options * @return a string containing the formatted date/time. */ public static String formatDateTime(Context context, long millis, int flags) { return formatDateRange(context, millis, millis, flags); } /** * @return a relative time string to display the time expressed by millis. Times * are counted starting at midnight, which means that assuming that the current * time is March 31st, 0:30: * <ul> * <li>"millis=0:10 today" will be displayed as "0:10"</li> * <li>"millis=11:30pm the day before" will be displayed as "Mar 30"</li> * </ul> * If the given millis is in a different year, then the full date is * returned in numeric format (e.g., "10/12/2008"). * * @param withPreposition If true, the string returned will include the correct * preposition ("at 9:20am", "on 10/12/2008" or "on May 29"). */ public static CharSequence getRelativeTimeSpanString(Context c, long millis, boolean withPreposition) { String result; long now = System.currentTimeMillis(); long span = Math.abs(now - millis); synchronized (DateUtils.class) { if (sNowTime == null) { sNowTime = new Time(); } if (sThenTime == null) { sThenTime = new Time(); } sNowTime.set(now); sThenTime.set(millis); int prepositionId; if (span < DAY_IN_MILLIS && sNowTime.weekDay == sThenTime.weekDay) { // Same day int flags = FORMAT_SHOW_TIME; result = formatDateRange(c, millis, millis, flags); prepositionId = R.string.preposition_for_time; } else if (sNowTime.year != sThenTime.year) { // Different years int flags = FORMAT_SHOW_DATE | FORMAT_SHOW_YEAR | FORMAT_NUMERIC_DATE; result = formatDateRange(c, millis, millis, flags); // This is a date (like "10/31/2008" so use the date preposition) prepositionId = R.string.preposition_for_date; } else { // Default int flags = FORMAT_SHOW_DATE | FORMAT_ABBREV_MONTH; result = formatDateRange(c, millis, millis, flags); prepositionId = R.string.preposition_for_date; } if (withPreposition) { Resources res = c.getResources(); result = res.getString(prepositionId, result); } } return result; } /** * Convenience function to return relative time string without preposition. * @param c context for resources * @param millis time in milliseconds * @return {@link CharSequence} containing relative time. * @see #getRelativeTimeSpanString(Context, long, boolean) */ public static CharSequence getRelativeTimeSpanString(Context c, long millis) { return getRelativeTimeSpanString(c, millis, false /* no preposition */); } private static Time sNowTime; private static Time sThenTime; }