Immutable representation of a date with an optional time and an optional time zone based on RFC 3339.
/*
* Copyright (c) 2010 Google Inc.
*
* 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.google.api.client.util;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.TimeZone;
/**
* Immutable representation of a date with an optional time and an optional time zone based on RFC
* 3339.
*
* @since 1.0
* @author Yaniv Inbar
*/
public class DateTime {
private static final TimeZone GMT = TimeZone.getTimeZone("GMT");
/**
* Date/time value expressed as the number of ms since the Unix epoch.
*
* If the time zone is specified, this value is normalized to UTC, so to format this date/time
* value, the time zone shift has to be applied.
*/
public final long value;
/** Specifies whether this is a date-only value. */
public final boolean dateOnly;
/**
* Time zone shift from UTC in minutes. If {@code null}, no time zone is set, and the time is
* always interpreted as local time.
*/
public final Integer tzShift;
public DateTime(Date date, TimeZone zone) {
long value = date.getTime();
dateOnly = false;
this.value = value;
tzShift = zone.getOffset(value) / 60000;
}
public DateTime(long value) {
this(false, value, null);
}
public DateTime(Date value) {
this(value.getTime());
}
public DateTime(long value, Integer tzShift) {
this(false, value, tzShift);
}
public DateTime(boolean dateOnly, long value, Integer tzShift) {
this.dateOnly = dateOnly;
this.value = value;
this.tzShift = tzShift;
}
/** Formats the value as an RFC 3339 date/time string. */
public String toStringRfc3339() {
StringBuilder sb = new StringBuilder();
Calendar dateTime = new GregorianCalendar(GMT);
long localTime = value;
Integer tzShift = this.tzShift;
if (tzShift != null) {
localTime += tzShift.longValue() * 60000;
}
dateTime.setTimeInMillis(localTime);
appendInt(sb, dateTime.get(Calendar.YEAR), 4);
sb.append('-');
appendInt(sb, dateTime.get(Calendar.MONTH) + 1, 2);
sb.append('-');
appendInt(sb, dateTime.get(Calendar.DAY_OF_MONTH), 2);
if (!dateOnly) {
sb.append('T');
appendInt(sb, dateTime.get(Calendar.HOUR_OF_DAY), 2);
sb.append(':');
appendInt(sb, dateTime.get(Calendar.MINUTE), 2);
sb.append(':');
appendInt(sb, dateTime.get(Calendar.SECOND), 2);
if (dateTime.isSet(Calendar.MILLISECOND)) {
sb.append('.');
appendInt(sb, dateTime.get(Calendar.MILLISECOND), 3);
}
}
if (tzShift != null) {
if (tzShift.intValue() == 0) {
sb.append('Z');
} else {
int absTzShift = tzShift.intValue();
if (tzShift > 0) {
sb.append('+');
} else {
sb.append('-');
absTzShift = -absTzShift;
}
int tzHours = absTzShift / 60;
int tzMinutes = absTzShift % 60;
appendInt(sb, tzHours, 2);
sb.append(':');
appendInt(sb, tzMinutes, 2);
}
}
return sb.toString();
}
@Override
public String toString() {
return toStringRfc3339();
}
@Override
public boolean equals(Object o) {
if (o == this) {
return true;
}
if (!(o instanceof DateTime)) {
return false;
}
DateTime other = (DateTime) o;
return dateOnly == other.dateOnly && value == other.value;
}
/**
* Parses an RFC 3339 date/time value.
*/
public static DateTime parseRfc3339(String str) throws NumberFormatException {
try {
Calendar dateTime = new GregorianCalendar(GMT);
int year = Integer.parseInt(str.substring(0, 4));
int month = Integer.parseInt(str.substring(5, 7)) - 1;
int day = Integer.parseInt(str.substring(8, 10));
int tzIndex;
int length = str.length();
boolean dateOnly = length <= 10 || Character.toUpperCase(str.charAt(10)) != 'T';
if (dateOnly) {
dateTime.set(year, month, day);
tzIndex = 10;
} else {
int hourOfDay = Integer.parseInt(str.substring(11, 13));
int minute = Integer.parseInt(str.substring(14, 16));
int second = Integer.parseInt(str.substring(17, 19));
dateTime.set(year, month, day, hourOfDay, minute, second);
if (str.charAt(19) == '.') {
int milliseconds = Integer.parseInt(str.substring(20, 23));
dateTime.set(Calendar.MILLISECOND, milliseconds);
tzIndex = 23;
} else {
tzIndex = 19;
}
}
Integer tzShiftInteger = null;
long value = dateTime.getTimeInMillis();
if (length > tzIndex) {
int tzShift;
if (Character.toUpperCase(str.charAt(tzIndex)) == 'Z') {
tzShift = 0;
} else {
tzShift = Integer.parseInt(str.substring(tzIndex + 1, tzIndex + 3)) * 60
+ Integer.parseInt(str.substring(tzIndex + 4, tzIndex + 6));
if (str.charAt(tzIndex) == '-') {
tzShift = -tzShift;
}
value -= tzShift * 60000;
}
tzShiftInteger = tzShift;
}
return new DateTime(dateOnly, value, tzShiftInteger);
} catch (StringIndexOutOfBoundsException e) {
throw new NumberFormatException("Invalid date/time format.");
}
}
/** Appends a zero-padded number to a string builder. */
private static void appendInt(StringBuilder sb, int num, int numDigits) {
if (num < 0) {
sb.append('-');
num = -num;
}
int x = num;
while (x > 0) {
x /= 10;
numDigits--;
}
for (int i = 0; i < numDigits; i++) {
sb.append('0');
}
if (num != 0) {
sb.append(num);
}
}
}
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