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Apache Commons Lang, a package of Java utility classes for the classes that are in java.lang's hierarchy, or are considered to be so standard as to justify existence in java.lang.

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * 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.
 */
package org.apache.commons.lang3.time;

import java.text.DateFormat;
import java.text.FieldPosition;
import java.text.Format;
import java.text.ParseException;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.Locale;
import java.util.TimeZone;

/**
 * FastDateFormat is a fast and thread-safe version of
 * {@link java.text.SimpleDateFormat}.
 *
 * 

To obtain an instance of FastDateFormat, use one of the static factory methods: * {@link #getInstance(String, TimeZone, Locale)}, {@link #getDateInstance(int, TimeZone, Locale)}, * {@link #getTimeInstance(int, TimeZone, Locale)}, or {@link #getDateTimeInstance(int, int, TimeZone, Locale)} *

* *

Since FastDateFormat is thread safe, you can use a static member instance:

* * private static final FastDateFormat DATE_FORMATTER = FastDateFormat.getDateTimeInstance(FastDateFormat.LONG, FastDateFormat.SHORT); * * *

This class can be used as a direct replacement to * {@link SimpleDateFormat} in most formatting and parsing situations. * This class is especially useful in multi-threaded server environments. * {@link SimpleDateFormat} is not thread-safe in any JDK version, * nor will it be as Sun have closed the bug/RFE. *

* *

All patterns are compatible with * SimpleDateFormat (except time zones and some year patterns - see below).

* *

Since 3.2, FastDateFormat supports parsing as well as printing.

* *

Java 1.4 introduced a new pattern letter, {@code 'Z'}, to represent * time zones in RFC822 format (eg. {@code +0800} or {@code -1100}). * This pattern letter can be used here (on all JDK versions).

* *

In addition, the pattern {@code 'ZZ'} has been made to represent * ISO 8601 extended format time zones (eg. {@code +08:00} or {@code -11:00}). * This introduces a minor incompatibility with Java 1.4, but at a gain of * useful functionality.

* *

Javadoc cites for the year pattern: For formatting, if the number of * pattern letters is 2, the year is truncated to 2 digits; otherwise it is * interpreted as a number. Starting with Java 1.7 a pattern of 'Y' or * 'YYY' will be formatted as '2003', while it was '03' in former Java * versions. FastDateFormat implements the behavior of Java 7.

* * @since 2.0 */ public class FastDateFormat extends Format implements DateParser, DatePrinter { /** * Required for serialization support. * * @see java.io.Serializable */ private static final long serialVersionUID = 2L; /** * FULL locale dependent date or time style. */ public static final int FULL = DateFormat.FULL; /** * LONG locale dependent date or time style. */ public static final int LONG = DateFormat.LONG; /** * MEDIUM locale dependent date or time style. */ public static final int MEDIUM = DateFormat.MEDIUM; /** * SHORT locale dependent date or time style. */ public static final int SHORT = DateFormat.SHORT; private static final FormatCache cache = new FormatCache() { @Override protected FastDateFormat createInstance(final String pattern, final TimeZone timeZone, final Locale locale) { return new FastDateFormat(pattern, timeZone, locale); } }; /** Our fast printer. */ private final FastDatePrinter printer; /** Our fast parser. */ private final FastDateParser parser; /** * Gets a formatter instance using the default pattern in the * default locale. * * @return a date/time formatter */ public static FastDateFormat getInstance() { return cache.getInstance(); } /** * Gets a formatter instance using the specified pattern in the * default locale. * * @param pattern {@link java.text.SimpleDateFormat} compatible * pattern * @return a pattern based date/time formatter * @throws IllegalArgumentException if pattern is invalid */ public static FastDateFormat getInstance(final String pattern) { return cache.getInstance(pattern, null, null); } /** * Gets a formatter instance using the specified pattern and * time zone. * * @param pattern {@link java.text.SimpleDateFormat} compatible * pattern * @param timeZone optional time zone, overrides time zone of * formatted date * @return a pattern based date/time formatter * @throws IllegalArgumentException if pattern is invalid */ public static FastDateFormat getInstance(final String pattern, final TimeZone timeZone) { return cache.getInstance(pattern, timeZone, null); } /** * Gets a formatter instance using the specified pattern and * locale. * * @param pattern {@link java.text.SimpleDateFormat} compatible * pattern * @param locale optional locale, overrides system locale * @return a pattern based date/time formatter * @throws IllegalArgumentException if pattern is invalid */ public static FastDateFormat getInstance(final String pattern, final Locale locale) { return cache.getInstance(pattern, null, locale); } /** * Gets a formatter instance using the specified pattern, time zone * and locale. * * @param pattern {@link java.text.SimpleDateFormat} compatible * pattern * @param timeZone optional time zone, overrides time zone of * formatted date * @param locale optional locale, overrides system locale * @return a pattern based date/time formatter * @throws IllegalArgumentException if pattern is invalid * or {@code null} */ public static FastDateFormat getInstance(final String pattern, final TimeZone timeZone, final Locale locale) { return cache.getInstance(pattern, timeZone, locale); } /** * Gets a date formatter instance using the specified style in the * default time zone and locale. * * @param style date style: FULL, LONG, MEDIUM, or SHORT * @return a localized standard date formatter * @throws IllegalArgumentException if the Locale has no date * pattern defined * @since 2.1 */ public static FastDateFormat getDateInstance(final int style) { return cache.getDateInstance(style, null, null); } /** * Gets a date formatter instance using the specified style and * locale in the default time zone. * * @param style date style: FULL, LONG, MEDIUM, or SHORT * @param locale optional locale, overrides system locale * @return a localized standard date formatter * @throws IllegalArgumentException if the Locale has no date * pattern defined * @since 2.1 */ public static FastDateFormat getDateInstance(final int style, final Locale locale) { return cache.getDateInstance(style, null, locale); } /** * Gets a date formatter instance using the specified style and * time zone in the default locale. * * @param style date style: FULL, LONG, MEDIUM, or SHORT * @param timeZone optional time zone, overrides time zone of * formatted date * @return a localized standard date formatter * @throws IllegalArgumentException if the Locale has no date * pattern defined * @since 2.1 */ public static FastDateFormat getDateInstance(final int style, final TimeZone timeZone) { return cache.getDateInstance(style, timeZone, null); } /** * Gets a date formatter instance using the specified style, time * zone and locale. * * @param style date style: FULL, LONG, MEDIUM, or SHORT * @param timeZone optional time zone, overrides time zone of * formatted date * @param locale optional locale, overrides system locale * @return a localized standard date formatter * @throws IllegalArgumentException if the Locale has no date * pattern defined */ public static FastDateFormat getDateInstance(final int style, final TimeZone timeZone, final Locale locale) { return cache.getDateInstance(style, timeZone, locale); } /** * Gets a time formatter instance using the specified style in the * default time zone and locale. * * @param style time style: FULL, LONG, MEDIUM, or SHORT * @return a localized standard time formatter * @throws IllegalArgumentException if the Locale has no time * pattern defined * @since 2.1 */ public static FastDateFormat getTimeInstance(final int style) { return cache.getTimeInstance(style, null, null); } /** * Gets a time formatter instance using the specified style and * locale in the default time zone. * * @param style time style: FULL, LONG, MEDIUM, or SHORT * @param locale optional locale, overrides system locale * @return a localized standard time formatter * @throws IllegalArgumentException if the Locale has no time * pattern defined * @since 2.1 */ public static FastDateFormat getTimeInstance(final int style, final Locale locale) { return cache.getTimeInstance(style, null, locale); } /** * Gets a time formatter instance using the specified style and * time zone in the default locale. * * @param style time style: FULL, LONG, MEDIUM, or SHORT * @param timeZone optional time zone, overrides time zone of * formatted time * @return a localized standard time formatter * @throws IllegalArgumentException if the Locale has no time * pattern defined * @since 2.1 */ public static FastDateFormat getTimeInstance(final int style, final TimeZone timeZone) { return cache.getTimeInstance(style, timeZone, null); } /** * Gets a time formatter instance using the specified style, time * zone and locale. * * @param style time style: FULL, LONG, MEDIUM, or SHORT * @param timeZone optional time zone, overrides time zone of * formatted time * @param locale optional locale, overrides system locale * @return a localized standard time formatter * @throws IllegalArgumentException if the Locale has no time * pattern defined */ public static FastDateFormat getTimeInstance(final int style, final TimeZone timeZone, final Locale locale) { return cache.getTimeInstance(style, timeZone, locale); } /** * Gets a date/time formatter instance using the specified style * in the default time zone and locale. * * @param dateStyle date style: FULL, LONG, MEDIUM, or SHORT * @param timeStyle time style: FULL, LONG, MEDIUM, or SHORT * @return a localized standard date/time formatter * @throws IllegalArgumentException if the Locale has no date/time * pattern defined * @since 2.1 */ public static FastDateFormat getDateTimeInstance(final int dateStyle, final int timeStyle) { return cache.getDateTimeInstance(dateStyle, timeStyle, null, null); } /** * Gets a date/time formatter instance using the specified style and * locale in the default time zone. * * @param dateStyle date style: FULL, LONG, MEDIUM, or SHORT * @param timeStyle time style: FULL, LONG, MEDIUM, or SHORT * @param locale optional locale, overrides system locale * @return a localized standard date/time formatter * @throws IllegalArgumentException if the Locale has no date/time * pattern defined * @since 2.1 */ public static FastDateFormat getDateTimeInstance(final int dateStyle, final int timeStyle, final Locale locale) { return cache.getDateTimeInstance(dateStyle, timeStyle, null, locale); } /** * Gets a date/time formatter instance using the specified style and * time zone in the default locale. * * @param dateStyle date style: FULL, LONG, MEDIUM, or SHORT * @param timeStyle time style: FULL, LONG, MEDIUM, or SHORT * @param timeZone optional time zone, overrides time zone of * formatted date * @return a localized standard date/time formatter * @throws IllegalArgumentException if the Locale has no date/time * pattern defined * @since 2.1 */ public static FastDateFormat getDateTimeInstance(final int dateStyle, final int timeStyle, final TimeZone timeZone) { return getDateTimeInstance(dateStyle, timeStyle, timeZone, null); } /** * Gets a date/time formatter instance using the specified style, * time zone and locale. * * @param dateStyle date style: FULL, LONG, MEDIUM, or SHORT * @param timeStyle time style: FULL, LONG, MEDIUM, or SHORT * @param timeZone optional time zone, overrides time zone of * formatted date * @param locale optional locale, overrides system locale * @return a localized standard date/time formatter * @throws IllegalArgumentException if the Locale has no date/time * pattern defined */ public static FastDateFormat getDateTimeInstance( final int dateStyle, final int timeStyle, final TimeZone timeZone, final Locale locale) { return cache.getDateTimeInstance(dateStyle, timeStyle, timeZone, locale); } // Constructor /** * Constructs a new FastDateFormat. * * @param pattern {@link java.text.SimpleDateFormat} compatible pattern * @param timeZone non-null time zone to use * @param locale non-null locale to use * @throws NullPointerException if pattern, timeZone, or locale is null. */ protected FastDateFormat(final String pattern, final TimeZone timeZone, final Locale locale) { this(pattern, timeZone, locale, null); } // Constructor /** * Constructs a new FastDateFormat. * * @param pattern {@link java.text.SimpleDateFormat} compatible pattern * @param timeZone non-null time zone to use * @param locale non-null locale to use * @param centuryStart The start of the 100-year period to use as the "default century" for 2 digit year parsing. If centuryStart is null, defaults to now - 80 years * @throws NullPointerException if pattern, timeZone, or locale is null. */ protected FastDateFormat(final String pattern, final TimeZone timeZone, final Locale locale, final Date centuryStart) { printer = new FastDatePrinter(pattern, timeZone, locale); parser = new FastDateParser(pattern, timeZone, locale, centuryStart); } // Format methods /** * Formats a {@link Date}, {@link Calendar} or * {@link Long} (milliseconds) object. * This method is an implementation of {@link Format#format(Object, StringBuffer, FieldPosition)} * * @param obj the object to format * @param toAppendTo the buffer to append to * @param pos the position - ignored * @return the buffer passed in */ @Override public StringBuffer format(final Object obj, final StringBuffer toAppendTo, final FieldPosition pos) { return toAppendTo.append(printer.format(obj)); } /** * Formats a millisecond {@code long} value. * * @param millis the millisecond value to format * @return the formatted string * @since 2.1 */ @Override public String format(final long millis) { return printer.format(millis); } /** * Formats a {@link Date} object using a {@link GregorianCalendar}. * * @param date the date to format * @return the formatted string */ @Override public String format(final Date date) { return printer.format(date); } /** * Formats a {@link Calendar} object. * * @param calendar the calendar to format * @return the formatted string */ @Override public String format(final Calendar calendar) { return printer.format(calendar); } /** * Formats a millisecond {@code long} value into the * supplied {@link StringBuffer}. * * @param millis the millisecond value to format * @param buf the buffer to format into * @return the specified string buffer * @since 2.1 * @deprecated Use {{@link #format(long, Appendable)}. */ @Deprecated @Override public StringBuffer format(final long millis, final StringBuffer buf) { return printer.format(millis, buf); } /** * Formats a {@link Date} object into the * supplied {@link StringBuffer} using a {@link GregorianCalendar}. * * @param date the date to format * @param buf the buffer to format into * @return the specified string buffer * @deprecated Use {{@link #format(Date, Appendable)}. */ @Deprecated @Override public StringBuffer format(final Date date, final StringBuffer buf) { return printer.format(date, buf); } /** * Formats a {@link Calendar} object into the * supplied {@link StringBuffer}. * * @param calendar the calendar to format * @param buf the buffer to format into * @return the specified string buffer * @deprecated Use {{@link #format(Calendar, Appendable)}. */ @Deprecated @Override public StringBuffer format(final Calendar calendar, final StringBuffer buf) { return printer.format(calendar, buf); } /** * Formats a millisecond {@code long} value into the * supplied {@link StringBuffer}. * * @param millis the millisecond value to format * @param buf the buffer to format into * @return the specified string buffer * @since 3.5 */ @Override public B format(final long millis, final B buf) { return printer.format(millis, buf); } /** * Formats a {@link Date} object into the * supplied {@link StringBuffer} using a {@link GregorianCalendar}. * * @param date the date to format * @param buf the buffer to format into * @return the specified string buffer * @since 3.5 */ @Override public B format(final Date date, final B buf) { return printer.format(date, buf); } /** * Formats a {@link Calendar} object into the * supplied {@link StringBuffer}. * * @param calendar the calendar to format * @param buf the buffer to format into * @return the specified string buffer * @since 3.5 */ @Override public B format(final Calendar calendar, final B buf) { return printer.format(calendar, buf); } // Parsing /* (non-Javadoc) * @see DateParser#parse(String) */ @Override public Date parse(final String source) throws ParseException { return parser.parse(source); } /* (non-Javadoc) * @see DateParser#parse(String, java.text.ParsePosition) */ @Override public Date parse(final String source, final ParsePosition pos) { return parser.parse(source, pos); } /* * (non-Javadoc) * @see org.apache.commons.lang3.time.DateParser#parse(String, java.text.ParsePosition, java.util.Calendar) */ @Override public boolean parse(final String source, final ParsePosition pos, final Calendar calendar) { return parser.parse(source, pos, calendar); } /* (non-Javadoc) * @see java.text.Format#parseObject(String, java.text.ParsePosition) */ @Override public Object parseObject(final String source, final ParsePosition pos) { return parser.parseObject(source, pos); } // Accessors /** * Gets the pattern used by this formatter. * * @return the pattern, {@link java.text.SimpleDateFormat} compatible */ @Override public String getPattern() { return printer.getPattern(); } /** * Gets the time zone used by this formatter. * *

This zone is always used for {@link Date} formatting.

* * @return the time zone */ @Override public TimeZone getTimeZone() { return printer.getTimeZone(); } /** * Gets the locale used by this formatter. * * @return the locale */ @Override public Locale getLocale() { return printer.getLocale(); } /** * Gets an estimate for the maximum string length that the * formatter will produce. * *

The actual formatted length will almost always be less than or * equal to this amount.

* * @return the maximum formatted length */ public int getMaxLengthEstimate() { return printer.getMaxLengthEstimate(); } // Basics /** * Compares two objects for equality. * * @param obj the object to compare to * @return {@code true} if equal */ @Override public boolean equals(final Object obj) { if (!(obj instanceof FastDateFormat)) { return false; } final FastDateFormat other = (FastDateFormat) obj; // no need to check parser, as it has same invariants as printer return printer.equals(other.printer); } /** * Returns a hash code compatible with equals. * * @return a hash code compatible with equals */ @Override public int hashCode() { return printer.hashCode(); } /** * Gets a debugging string version of this formatter. * * @return a debugging string */ @Override public String toString() { return "FastDateFormat[" + printer.getPattern() + "," + printer.getLocale() + "," + printer.getTimeZone().getID() + "]"; } /** * Performs the formatting by applying the rules to the * specified calendar. * * @param calendar the calendar to format * @param buf the buffer to format into * @return the specified string buffer * @deprecated Use {@link #format(Calendar, Appendable)} */ @Deprecated protected StringBuffer applyRules(final Calendar calendar, final StringBuffer buf) { return printer.applyRules(calendar, buf); } }