Java tutorial
/* * Portions Copyright 2007-2008 Sun Microsystems, Inc. All rights reserved. */ /* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. The ASF licenses this file to You * 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. For additional information regarding * copyright in this work, please see the NOTICE file in the top level * directory of this distribution. */ package com.sun.socialsite.util; import java.text.ParseException; import java.text.ParsePosition; import java.text.DateFormat; import java.text.FieldPosition; import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.Date; import java.util.Locale; import java.util.TimeZone; import org.apache.commons.lang.StringUtils; /** * General purpose date utilities. * * TODO: all date handling functions need to be aware of locale and timezone. */ public abstract class DateUtil { public static final long millisInDay = 86400000; // a bunch of date formats private static final String formatDefaultDate = "dd.MM.yyyy"; private static final String formatDefaultDateMinimal = "d.M.yy"; private static final String formatDefaultTimestamp = "yyyy-MM-dd HH:mm:ss.SSS"; private static final String formatFriendlyTimestamp = "dd.MM.yyyy HH:mm:ss"; private static final String format6chars = "yyyyMM"; private static final String format8chars = "yyyyMMdd"; private static final String formatIso8601 = "yyyy-MM-dd'T'HH:mm:ssZ"; private static final String formatIso8601Day = "yyyy-MM-dd"; private static final String formatRfc822 = "EEE, d MMM yyyy HH:mm:ss Z"; /** * Returns a Date set to the first possible millisecond of the day, just * after midnight. If a null day is passed in, a new Date is created. * midnight (00m 00h 00s) */ public static Date getStartOfDay(Date day) { return getStartOfDay(day, Calendar.getInstance()); } /** * Returns a Date set to the first possible millisecond of the day, just * after midnight. If a null day is passed in, a new Date is created. * midnight (00m 00h 00s) */ public static Date getStartOfDay(Date day, Calendar cal) { if (day == null) day = new Date(); cal.setTime(day); cal.set(Calendar.HOUR_OF_DAY, cal.getMinimum(Calendar.HOUR_OF_DAY)); cal.set(Calendar.MINUTE, cal.getMinimum(Calendar.MINUTE)); cal.set(Calendar.SECOND, cal.getMinimum(Calendar.SECOND)); cal.set(Calendar.MILLISECOND, cal.getMinimum(Calendar.MILLISECOND)); return cal.getTime(); } /** * Returns a Date set to the last possible millisecond of the day, just * before midnight. If a null day is passed in, a new Date is created. * midnight (00m 00h 00s) */ public static Date getEndOfDay(Date day) { return getEndOfDay(day, Calendar.getInstance()); } public static Date getEndOfDay(Date day, Calendar cal) { if (day == null) day = new Date(); cal.setTime(day); cal.set(Calendar.HOUR_OF_DAY, cal.getMaximum(Calendar.HOUR_OF_DAY)); cal.set(Calendar.MINUTE, cal.getMaximum(Calendar.MINUTE)); cal.set(Calendar.SECOND, cal.getMaximum(Calendar.SECOND)); cal.set(Calendar.MILLISECOND, cal.getMaximum(Calendar.MILLISECOND)); return cal.getTime(); } /** * Returns a Date set to the first possible millisecond of the hour. * If a null day is passed in, a new Date is created. */ public static Date getStartOfHour(Date day) { return getStartOfHour(day, Calendar.getInstance()); } /** * Returns a Date set to the first possible millisecond of the hour. * If a null day is passed in, a new Date is created. */ public static Date getStartOfHour(Date day, Calendar cal) { if (day == null) day = new Date(); cal.setTime(day); cal.set(Calendar.MINUTE, cal.getMinimum(Calendar.MINUTE)); cal.set(Calendar.SECOND, cal.getMinimum(Calendar.SECOND)); cal.set(Calendar.MILLISECOND, cal.getMinimum(Calendar.MILLISECOND)); return cal.getTime(); } /** * Returns a Date set to the last possible millisecond of the day, just * before midnight. If a null day is passed in, a new Date is created. * midnight (00m 00h 00s) */ public static Date getEndOfHour(Date day) { return getEndOfHour(day, Calendar.getInstance()); } public static Date getEndOfHour(Date day, Calendar cal) { if (day == null || cal == null) { return day; } cal.setTime(day); cal.set(Calendar.MINUTE, cal.getMaximum(Calendar.MINUTE)); cal.set(Calendar.SECOND, cal.getMaximum(Calendar.SECOND)); cal.set(Calendar.MILLISECOND, cal.getMaximum(Calendar.MILLISECOND)); return cal.getTime(); } /** * Returns a Date set to the first possible millisecond of the minute. * If a null day is passed in, a new Date is created. */ public static Date getStartOfMinute(Date day) { return getStartOfMinute(day, Calendar.getInstance()); } /** * Returns a Date set to the first possible millisecond of the minute. * If a null day is passed in, a new Date is created. */ public static Date getStartOfMinute(Date day, Calendar cal) { if (day == null) day = new Date(); cal.setTime(day); cal.set(Calendar.SECOND, cal.getMinimum(Calendar.SECOND)); cal.set(Calendar.MILLISECOND, cal.getMinimum(Calendar.MILLISECOND)); return cal.getTime(); } /** * Returns a Date set to the last possible millisecond of the minute. * If a null day is passed in, a new Date is created. */ public static Date getEndOfMinute(Date day) { return getEndOfMinute(day, Calendar.getInstance()); } public static Date getEndOfMinute(Date day, Calendar cal) { if (day == null || cal == null) { return day; } cal.setTime(day); cal.set(Calendar.SECOND, cal.getMaximum(Calendar.SECOND)); cal.set(Calendar.MILLISECOND, cal.getMaximum(Calendar.MILLISECOND)); return cal.getTime(); } /** * Returns a Date set to the first possible millisecond of the month, just * after midnight. If a null day is passed in, a new Date is created. * midnight (00m 00h 00s) */ public static Date getStartOfMonth(Date day) { return getStartOfMonth(day, Calendar.getInstance()); } public static Date getStartOfMonth(Date day, Calendar cal) { if (day == null) day = new Date(); cal.setTime(day); // set time to start of day cal.set(Calendar.HOUR_OF_DAY, cal.getMinimum(Calendar.HOUR_OF_DAY)); cal.set(Calendar.MINUTE, cal.getMinimum(Calendar.MINUTE)); cal.set(Calendar.SECOND, cal.getMinimum(Calendar.SECOND)); cal.set(Calendar.MILLISECOND, cal.getMinimum(Calendar.MILLISECOND)); // set time to first day of month cal.set(Calendar.DAY_OF_MONTH, 1); return cal.getTime(); } /** * Returns a Date set to the last possible millisecond of the month, just * before midnight. If a null day is passed in, a new Date is created. * midnight (00m 00h 00s) */ public static Date getEndOfMonth(Date day) { return getEndOfMonth(day, Calendar.getInstance()); } public static Date getEndOfMonth(Date day, Calendar cal) { if (day == null) day = new Date(); cal.setTime(day); // set time to end of day cal.set(Calendar.HOUR_OF_DAY, cal.getMaximum(Calendar.HOUR_OF_DAY)); cal.set(Calendar.MINUTE, cal.getMaximum(Calendar.MINUTE)); cal.set(Calendar.SECOND, cal.getMaximum(Calendar.SECOND)); cal.set(Calendar.MILLISECOND, cal.getMaximum(Calendar.MILLISECOND)); // set time to first day of month cal.set(Calendar.DAY_OF_MONTH, 1); // add one month cal.add(Calendar.MONTH, 1); // back up one day cal.add(Calendar.DAY_OF_MONTH, -1); return cal.getTime(); } /** * Returns a Date set just to Noon, to the closest possible millisecond * of the day. If a null day is passed in, a new Date is created. * nnoon (00m 12h 00s) */ public static Date getNoonOfDay(Date day, Calendar cal) { if (day == null) day = new Date(); cal.setTime(day); cal.set(Calendar.HOUR_OF_DAY, 12); cal.set(Calendar.MINUTE, cal.getMinimum(Calendar.MINUTE)); cal.set(Calendar.SECOND, cal.getMinimum(Calendar.SECOND)); cal.set(Calendar.MILLISECOND, cal.getMinimum(Calendar.MILLISECOND)); return cal.getTime(); } /** * Returns a java.sql.Timestamp equal to the current time **/ public static java.sql.Timestamp now() { return new java.sql.Timestamp(new java.util.Date().getTime()); } /** * Returns a string the represents the passed-in date parsed * according to the passed-in format. Returns an empty string * if the date or the format is null. **/ public static String format(Date aDate, DateFormat aFormat) { if (aDate == null || aFormat == null) { return ""; } synchronized (aFormat) { return aFormat.format(aDate); } } /** * Returns a Date using the passed-in string and format. Returns null if the string * is null or empty or if the format is null. The string must match the format. **/ public static Date parse(String aValue, DateFormat aFormat) throws ParseException { if (StringUtils.isEmpty(aValue) || aFormat == null) { return null; } synchronized (aFormat) { return aFormat.parse(aValue); } } /** * Returns true if endDate is after startDate or if startDate equals endDate * or if they are the same date. Returns false if either value is null. **/ public static boolean isValidDateRange(Date startDate, Date endDate) { return isValidDateRange(startDate, endDate, true); } /** * Returns true if endDate is after startDate or if startDate equals endDate. * Returns false if either value is null. If equalOK, returns true if the * dates are equal. **/ public static boolean isValidDateRange(Date startDate, Date endDate, boolean equalOK) { // false if either value is null if (startDate == null || endDate == null) { return false; } if (equalOK) { // true if they are equal if (startDate.equals(endDate)) { return true; } } // true if endDate after startDate if (endDate.after(startDate)) { return true; } return false; } // convenience method returns minimal date format public static DateFormat defaultDateFormat() { return DateUtil.friendlyDateFormat(true); } // convenience method returns minimal date format public static DateFormat minimalDateFormat() { return friendlyDateFormat(true); } // convenience method that returns friendly data format // using full month, day, year digits. public static DateFormat fullDateFormat() { return friendlyDateFormat(false); } /** * Returns a "friendly" date format. * @param mimimalFormat Should the date format allow single digits. **/ public static DateFormat friendlyDateFormat(boolean minimalFormat) { if (minimalFormat) { return new SimpleDateFormat(formatDefaultDateMinimal); } return new SimpleDateFormat(formatDefaultDate); } // returns full timestamp format public static DateFormat defaultTimestampFormat() { return new SimpleDateFormat(formatDefaultTimestamp); } // convenience method returns long friendly timestamp format public static DateFormat friendlyTimestampFormat() { return new SimpleDateFormat(formatFriendlyTimestamp); } // get a DateForm which outputs rounded-off relative terms // (e.g. "2 hours ago") public static DateFormat roundedRelativeFormat() { return new DateFormat() { public StringBuffer format(Date date, StringBuffer toAppendTo, FieldPosition fieldPosition) { // TODO: Some better (and more localizable) way to do this? Date now = new Date(); long secondsDiff = (now.getTime() - date.getTime()) / 1000; if (secondsDiff <= 1) { return toAppendTo.append("1 second ago"); } else if (secondsDiff < 60) { return toAppendTo.append(secondsDiff).append(" seconds ago"); } else if (secondsDiff < (2 * 60)) { return toAppendTo.append("1 minute ago"); } else if (secondsDiff < (60 * 60)) { return toAppendTo.append((secondsDiff / 60)).append(" minutes ago"); } else if (secondsDiff < (2 * 60 * 60)) { return toAppendTo.append("1 hour ago"); } else if (secondsDiff < (24 * 60 * 60)) { return toAppendTo.append((secondsDiff / (60 * 60))).append(" hours ago"); } else if (secondsDiff < (2 * 24 * 60 * 60)) { return toAppendTo.append("yesterday"); } else { return toAppendTo.append((secondsDiff / (24 * 60 * 60))).append(" days ago"); } } public Date parse(String source, ParsePosition pos) { throw new UnsupportedOperationException(); } }; } // convenience method returns minimal date format public static DateFormat get8charDateFormat() { return new SimpleDateFormat(format8chars); } // convenience method returns minimal date format public static DateFormat get6charDateFormat() { return new SimpleDateFormat(format6chars); } // convenience method returns minimal date format public static DateFormat getIso8601DateFormat() { return new SimpleDateFormat(formatIso8601); } // convenience method returns minimal date format public static DateFormat getIso8601DayDateFormat() { return new SimpleDateFormat(formatIso8601Day); } // convenience method returns minimal date format public static DateFormat getRfc822DateFormat() { // http://www.w3.org/Protocols/rfc822/Overview.html#z28 // Using Locale.US to fix ROL-725 and ROL-628 return new SimpleDateFormat(formatRfc822, Locale.US); } // convenience method public static String defaultDate(Date date) { return format(date, defaultDateFormat()); } // convenience method using minimal date format public static String minimalDate(Date date) { return format(date, DateUtil.minimalDateFormat()); } public static String fullDate(Date date) { return format(date, DateUtil.fullDateFormat()); } /** * Format the date using the "friendly" date format. */ public static String friendlyDate(Date date, boolean minimalFormat) { return format(date, friendlyDateFormat(minimalFormat)); } // convenience method public static String friendlyDate(Date date) { return format(date, friendlyDateFormat(true)); } // convenience method public static String defaultTimestamp(Date date) { return format(date, defaultTimestampFormat()); } // convenience method returns long friendly formatted timestamp public static String friendlyTimestamp(Date date) { return format(date, friendlyTimestampFormat()); } // convenience method returns 8 char day stamp YYYYMMDD public static String format8chars(Date date) { return format(date, get8charDateFormat()); } // convenience method returns 6 char month stamp YYYYMM public static String format6chars(Date date) { return format(date, get6charDateFormat()); } // convenience method returns long friendly formatted timestamp public static String formatIso8601Day(Date date) { return format(date, getIso8601DayDateFormat()); } public static String formatRfc822(Date date) { return format(date, getRfc822DateFormat()); } // This is a hack, but it seems to work public static String formatIso8601(Date date) { if (date == null) return ""; // Add a colon 2 chars before the end of the string // to make it a valid ISO-8601 date. String str = format(date, getIso8601DateFormat()); StringBuffer sb = new StringBuffer(); sb.append(str.substring(0, str.length() - 2)); sb.append(":"); sb.append(str.substring(str.length() - 2)); return sb.toString(); } public static Date parseIso8601(String value) throws Exception { return ISO8601DateParser.parse(value); } /** * Parse data as either 6-char or 8-char format. */ public static Date parseWeblogURLDateString(String dateString, TimeZone tz, Locale locale) { Date ret = new Date(); DateFormat char8DateFormat = DateUtil.get8charDateFormat(); DateFormat char6DateFormat = DateUtil.get6charDateFormat(); if (dateString != null && dateString.length() == 8 && StringUtils.isNumeric(dateString)) { ParsePosition pos = new ParsePosition(0); ret = char8DateFormat.parse(dateString, pos); // make sure the requested date is not in the future Date today = null; Calendar todayCal = Calendar.getInstance(); todayCal = Calendar.getInstance(tz, locale); todayCal.setTime(new Date()); today = todayCal.getTime(); if (ret.after(today)) { ret = today; } } else if (dateString != null && dateString.length() == 6 && StringUtils.isNumeric(dateString)) { ParsePosition pos = new ParsePosition(0); ret = char6DateFormat.parse(dateString, pos); // make sure the requested date is not in the future Calendar todayCal = Calendar.getInstance(); todayCal = Calendar.getInstance(tz, locale); todayCal.setTime(new Date()); Date today = todayCal.getTime(); if (ret.after(today)) { ret = today; } } return ret; } }