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Posted to dev@commons.apache.org by st...@apache.org on 2002/09/04 23:11:41 UTC
cvs commit: jakarta-commons-sandbox/lang CalendarUtils.java
stevencaswell 2002/09/04 14:11:41
Added: lang CalendarUtils.java
Log:
initial add to sandbox for investigation - CalendarUtilsTest accompanies with test
Revision Changes Path
1.1 jakarta-commons-sandbox/lang/CalendarUtils.java
Index: CalendarUtils.java
===================================================================
// package org.apache.commons.lang;
/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2002 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution, if
* any, must include the following acknowlegement:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowlegement may appear in the software itself,
* if and wherever such third-party acknowlegements normally appear.
*
* 4. The names "The Jakarta Project", "Commons", and "Apache Software
* Foundation" must not be used to endorse or promote products derived
* from this software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache"
* nor may "Apache" appear in their names without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
import java.text.*;
import java.util.*;
/**
* A suite of utilities surrounding the use of the Calendar and Date object.
*
* @author <a href="mailto:sergek@lokitech.com">Serge Knystautas</a>
*/
public class CalendarUtils {
/**
* This is half a month, so this represents whether a date is in the top
* or bottom half of the month.
*/
public final static int SEMI_MONTH = 1001;
private static final int[][] fields = {
{Calendar.MILLISECOND},
{Calendar.SECOND},
{Calendar.MINUTE},
{Calendar.HOUR_OF_DAY, Calendar.HOUR},
{Calendar.DATE, Calendar.DAY_OF_MONTH, Calendar.AM_PM /* Calendar.DAY_OF_YEAR, Calendar.DAY_OF_WEEK, Calendar.DAY_OF_WEEK_IN_MONTH */},
{Calendar.MONTH, CalendarUtils.SEMI_MONTH},
{Calendar.YEAR},
{Calendar.ERA}};
private static DateFormat[] dateFormats = {
//3/31/92 10:00:07 PST
new SimpleDateFormat("M/dd/yy h:mm:ss z"),
//January 23, 1987 10:05pm
new SimpleDateFormat("MMM d, yyyy h:mm a"),
//22:00 GMT
new SimpleDateFormat("h:mm z")};
/**
* A week range, starting on Sunday.
*/
public final static int RANGE_WEEK_SUNDAY = 1;
/**
* A week range, starting on Monday.
*/
public final static int RANGE_WEEK_MONDAY = 2;
/**
* A week range, starting on the day focused.
*/
public final static int RANGE_WEEK_RELATIVE = 3;
/**
* A week range, centered around the day focused.
*/
public final static int RANGE_WEEK_CENTER = 4;
/**
* A month range, the week starting on Sunday.
*/
public final static int RANGE_MONTH_SUNDAY = 5;
/**
* A month range, the week starting on Monday.
*/
public final static int RANGE_MONTH_MONDAY = 6;
/**
* See the other round method. Works with a Date object.
*/
public static Date round(Date val, int field) {
GregorianCalendar gval = new GregorianCalendar();
gval.setTime(val);
modify(gval, field, true);
return gval.getTime();
}
/**
* Round this date, leaving the field specified as the most significant
* field. For example, if you had the datetime of 28 Mar 2002
* 13:45:01.231, if this was passed with HOUR, it would return 28 Mar
* 2002 14:00:00.000. If this was passed with MONTH, it would return
* 1 April 2002 0:00:00.000.
*/
public static Calendar round(Calendar val, int field) {
Calendar rounded = (Calendar) val.clone();
modify(rounded, field, true);
return rounded;
}
/**
* See the other round method. Works with an Object, trying to
* use it as either a Date or Calendar.
*/
public static Date round(Object val, int field) {
if (val instanceof Date) {
return round((Date) val, field);
} else if (val instanceof Calendar) {
return round((Calendar) val, field).getTime();
} else {
throw new ClassCastException("Could not round " + val);
}
}
/**
* See the other trunc method. Works with a Date.
*/
public static Date trunc(Date val, int field) {
GregorianCalendar gval = new GregorianCalendar();
gval.setTime(val);
modify(gval, field, false);
return gval.getTime();
}
/**
* Truncate this date, leaving the field specified as the most significant
* field. For example, if you had the datetime of 28 Mar 2002
* 13:45:01.231, if you passed with HOUR, it would return 28 Mar
* 2002 13:00:00.000. If this was passed with MONTH, it would return
* 1 Mar 2002 0:00:00.000.
*/
public static Calendar trunc(Calendar val, int field) {
Calendar truncated = (Calendar) val.clone();
modify(truncated, field, false);
return truncated;
}
/**
* See the other trunc method. Works with an Object, trying to
* use it as either a Date or Calendar.
*/
public static Date trunc(Object val, int field) {
if (val instanceof Date) {
return trunc((Date) val, field);
} else if (val instanceof Calendar) {
return trunc((Calendar) val, field).getTime();
} else {
throw new ClassCastException("Could not trunc " + val);
}
}
private static void modify(Calendar val, int field, boolean round) {
boolean roundUp = false;
for (int i = 0; i < fields.length; i++) {
for (int j = 0; j < fields[i].length; j++) {
if (fields[i][j] == field) {
//This is our field... we stop looping
if (round && roundUp) {
if (field == CalendarUtils.SEMI_MONTH) {
//This is a special case that's hard to generalize
//If the date is 1, we round up to 16, otherwise
// we subtract 15 days and add 1 month
if (val.get(Calendar.DATE) == 1) {
val.add(Calendar.DATE, 15);
} else {
val.add(Calendar.DATE, -15);
val.add(Calendar.MONTH, 1);
}
} else {
//We need at add one to this field since the
// last number causes us to round up
val.add(fields[i][0], 1);
}
}
return;
}
}
//We have various fields that are not easy roundings
int offset = 0;
boolean offsetSet = false;
//These are special types of fields that require different rounding rules
switch (field) {
case CalendarUtils.SEMI_MONTH:
if (fields[i][0] == Calendar.DATE) {
//If we're going to drop the DATE field's value,
// we want to do this our own way.
//We need to subtrace 1 since the date has a minimum of 1
offset = val.get(Calendar.DATE) - 1;
//If we're above 15 days adjustment, that means we're in the
// bottom half of the month and should stay accordingly.
if (offset >= 15) {
offset -= 15;
}
//Record whether we're in the top or bottom half of that range
roundUp = offset > 7;
offsetSet = true;
}
break;
case Calendar.AM_PM:
if (fields[i][0] == Calendar.HOUR) {
//If we're going to drop the HOUR field's value,
// we want to do this our own way.
offset = val.get(Calendar.HOUR);
if (offset >= 12) {
offset -= 12;
}
roundUp = offset > 6;
offsetSet = true;
}
break;
}
if (!offsetSet) {
int min = val.getActualMinimum(fields[i][0]);
int max = val.getActualMaximum(fields[i][0]);
//Calculate the offset from the minimum allowed value
offset = val.get(fields[i][0]) - min;
//Set roundUp if this is more than half way between the minimum and maximum
roundUp = offset > ((max - min) / 2);
}
//We need to remove this field
val.add(fields[i][0], -offset);
}
throw new RuntimeException("We do not support that field.");
}
/**
* Parses strings the way that CVS supports it... very human readable
*/
public static Calendar parse(String original) {
return parse(original, Locale.getDefault());
}
/**
* Parses strings the way that CVS supports it... very human readable
*/
public static Calendar parse(String original, Locale locale) {
//Get the symbol names
DateFormatSymbols symbols = new DateFormatSymbols(locale);
//Prep the string to parse
String value = original.toLowerCase().trim();
//Get the current date/time
Calendar now = Calendar.getInstance();
if (value.endsWith(" ago")) {
//If this was a date that was "ago" the current time...
//Strip out the ' ago' part
value = value.substring(0, value.length() - 4);
//Split the value and unit
int start = value.indexOf(" ");
if (start < 0) {
throw new RuntimeException("Could not find space in between value and unit");
}
String unit = value.substring(start + 1);
value = value.substring(0, start);
//We support "a week", so we need to parse the value as "a"
int val = 0;
if (value.equals("a") || value.equals("an")) {
val = 1;
} else {
val = Integer.parseInt(value);
}
//Determine the unit
if (unit.equals("milliseconds") || unit.equals("millisecond")) {
now.add(Calendar.MILLISECOND, -val);
} else if (unit.equals("seconds") || unit.equals("second")) {
now.add(Calendar.SECOND, -val);
} else if (unit.equals("minutes") || unit.equals("minute")) {
now.add(Calendar.MINUTE, -val);
} else if (unit.equals("hours") || unit.equals("hour")) {
now.add(Calendar.HOUR, -val);
} else if (unit.equals("days") || unit.equals("day")) {
now.add(Calendar.DATE, -val);
} else if (unit.equals("weeks") || unit.equals("week")) {
now.add(Calendar.DATE, -val * 7);
} else if (unit.equals("fortnights") || unit.equals("fortnight")) {
now.add(Calendar.DATE, -val * 14);
} else if (unit.equals("months") || unit.equals("month")) {
now.add(Calendar.MONTH, -val);
} else if (unit.equals("years") || unit.equals("year")) {
now.add(Calendar.YEAR, -val);
} else {
throw new RuntimeException("We do not understand that many units ago");
}
return now;
} else if (value.startsWith("last ")) {
//If this was the last time a certain field was met
//Strip out the 'last ' part
value = value.substring(5);
//Get the current date/time
String[] strings = symbols.getWeekdays();
for (int i = 0; i < strings.length; i++) {
if (value.equalsIgnoreCase(strings[i])) {
//How many days after Sunday
int daysAgo = now.get(Calendar.DAY_OF_WEEK) - i;
if (daysAgo <= 0) {
daysAgo += 7;
}
now.add(Calendar.DATE, -daysAgo);
return now;
}
}
strings = symbols.getMonths();
for (int i = 0; i < strings.length; i++) {
if (value.equalsIgnoreCase(strings[i])) {
//How many days after January
int monthsAgo = now.get(Calendar.MONTH) - i;
if (monthsAgo <= 0) {
monthsAgo += 12;
}
now.add(Calendar.MONTH, -monthsAgo);
return now;
}
}
if (value.equals("week")) {
now.add(Calendar.DATE, -7);
return now;
}
} else if (value.equals("yesterday")) {
now.add(Calendar.DATE, -1);
return now;
} else if (value.equals("tomorrow")) {
now.add(Calendar.DATE, 1);
return now;
}
//Try to parse the date a number of different ways
for (int i = 0; i < dateFormats.length; i++) {
try {
Date datetime = dateFormats[i].parse(original);
Calendar cal = Calendar.getInstance();
cal.setTime(datetime);
return cal;
} catch (ParseException pe) {
//we ignore this and just keep trying
}
}
throw new RuntimeException("Unable to parse '" + original + "'.");
}
/**
* This constructs an Iterator that will start and stop over a date
* range based on the focused date and the range style. For instance,
* passing Thursday, July 4, 2002 and a RANGE_MONTH_SUNDAY will return
* an Iterator that starts with Sunday, June 30, 2002 and ends with
* Saturday, August 3, 2002.
*/
public static Iterator getCalendarIterator(Calendar focus, int rangeStyle) {
Calendar start = null;
Calendar end = null;
int startCutoff = Calendar.SUNDAY;
int endCutoff = Calendar.SATURDAY;
switch (rangeStyle) {
case RANGE_MONTH_SUNDAY:
case RANGE_MONTH_MONDAY:
//Set start to the first of the month
start = trunc(focus, Calendar.MONTH);
//Set end to the last of the month
end = (Calendar) start.clone();
end.add(Calendar.MONTH, 1);
end.add(Calendar.DATE, -1);
//Loop start back to the previous sunday or monday
if (rangeStyle == RANGE_MONTH_MONDAY) {
startCutoff = Calendar.MONDAY;
endCutoff = Calendar.SUNDAY;
}
break;
case RANGE_WEEK_SUNDAY:
case RANGE_WEEK_MONDAY:
case RANGE_WEEK_RELATIVE:
case RANGE_WEEK_CENTER:
//Set start and end to the current date
start = trunc(focus, Calendar.DATE);
end = trunc(focus, Calendar.DATE);
switch (rangeStyle) {
case RANGE_WEEK_SUNDAY:
//already set by default
break;
case RANGE_WEEK_MONDAY:
startCutoff = Calendar.MONDAY;
endCutoff = Calendar.SUNDAY;
break;
case RANGE_WEEK_RELATIVE:
startCutoff = focus.get(Calendar.DAY_OF_WEEK);
endCutoff = startCutoff - 1;
break;
case RANGE_WEEK_CENTER:
startCutoff = focus.get(Calendar.DAY_OF_WEEK) - 3;
endCutoff = focus.get(Calendar.DAY_OF_WEEK) + 3;
break;
}
break;
default:
throw new RuntimeException("The range style " + rangeStyle + " is not valid.");
}
if (startCutoff < Calendar.SUNDAY) {
startCutoff += 7;
}
if (endCutoff > Calendar.SATURDAY) {
endCutoff -= 7;
}
while (start.get(Calendar.DAY_OF_WEEK) != startCutoff) {
start.add(Calendar.DATE, -1);
}
while (end.get(Calendar.DAY_OF_WEEK) != endCutoff) {
end.add(Calendar.DATE, 1);
}
final Calendar startFinal = start;
final Calendar endFinal = end;
Iterator it = new Iterator() {
Calendar spot = null;
{
spot = startFinal;
spot.add(Calendar.DATE, -1);
}
public boolean hasNext() {
return spot.before(endFinal);
}
public Object next() {
if (spot.equals(endFinal)) {
throw new NoSuchElementException();
}
spot.add(Calendar.DATE, 1);
return spot.clone();
}
public void remove() {
throw new UnsupportedOperationException();
}
};
return it;
}
/**
* See the other getCalendarIterator. Works with a Date.
*/
public static Iterator getCalendarIterator(Date focus, int rangeStyle) {
GregorianCalendar gval = new GregorianCalendar();
gval.setTime(focus);
return getCalendarIterator(gval, rangeStyle);
}
/**
* See the other getCalendarIterator. Works with an Object, trying
* to use it as a Date or Calendar.
*/
public static Iterator getCalendarIterator(Object focus, int rangeStyle) {
if (focus instanceof Date) {
return getCalendarIterator((Date) focus, rangeStyle);
} else if (focus instanceof Calendar) {
return getCalendarIterator((Calendar) focus, rangeStyle);
} else {
throw new ClassCastException("Could not iterate based on " + focus);
}
}
}
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