FastDateFormat.java
/*
* 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
*
* https://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}.
*
* <p>
* 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)}
* </p>
*
* <p>
* Since FastDateFormat is thread safe, you can use a static member instance:
* </p>
* {@code
* private static final FastDateFormat DATE_FORMATTER = FastDateFormat.getDateTimeInstance(FastDateFormat.LONG, FastDateFormat.SHORT);
* }
*
* <p>
* 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.
* </p>
*
* <p>
* All patterns are compatible with SimpleDateFormat (except time zones and some year patterns - see below).
* </p>
*
* <p>
* Since 3.2, FastDateFormat supports parsing as well as printing.
* </p>
*
* <p>
* Java 1.4 introduced a new pattern letter, {@code 'Z'}, to represent time zones in RFC822 format (for example, {@code +0800} or {@code -1100}). This pattern letter can
* be used here (on all JDK versions).
* </p>
*
* <p>
* In addition, the pattern {@code 'ZZ'} has been made to represent ISO 8601 extended format time zones (for example, {@code +08:00} or {@code -11:00}). This introduces
* a minor incompatibility with Java 1.4, but at a gain of useful functionality.
* </p>
*
* <p>
* Javadoc cites for the year pattern: <i>For formatting, if the number of pattern letters is 2, the year is truncated to 2 digits; otherwise it is interpreted
* as a number.</i> 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.
* </p>
*
* @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 AbstractFormatCache<FastDateFormat> CACHE = new AbstractFormatCache<FastDateFormat>() {
@Override
protected FastDateFormat createInstance(final String pattern, final TimeZone timeZone, final Locale locale) {
return new FastDateFormat(pattern, timeZone, locale);
}
};
/**
* Clears the cache.
*/
static void clear() {
AbstractFormatCache.clear();
CACHE.clearInstance();
}
/**
* Gets a date formatter instance using the specified style in the default time zone and locale.
*
* @param style date style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #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: {@link #FULL}, LO{@link #FULL},{@link #MEDIUM}, or {@link #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: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #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: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #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 date/time formatter instance using the specified style in the default time zone and locale.
*
* @param dateStyle date style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #SHORT}.
* @param timeStyle time style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #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: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #SHORT}.
* @param timeStyle time style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #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: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #SHORT}.
* @param timeStyle time style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #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: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #SHORT}.
* @param timeStyle time style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #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);
}
/**
* 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 and time zone.
*
* @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 locale using the default time zone.
*
* @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 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, 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 time formatter instance using the specified style in the default time zone and locale.
*
* @param style time style: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #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: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #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: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #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: {@link #FULL}, {@link #LONG}, {@link #MEDIUM}, or {@link #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);
}
/** Our fast printer. */
private final FastDatePrinter printer;
/** Our fast parser. */
private final FastDateParser parser;
// 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);
}
/**
* 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);
}
/**
* 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.format(calendar, buf);
}
// 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);
}
/**
* 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 {@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 extends Appendable> B format(final Calendar calendar, final B buf) {
return printer.format(calendar, 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 {@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 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 extends Appendable> B format(final Date date, final B buf) {
return printer.format(date, 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 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 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 extends Appendable> B format(final long millis, final B buf) {
return printer.format(millis, 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 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}, {@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 given buffer.
*/
@Override
public StringBuffer format(final Object obj, final StringBuffer toAppendTo, final FieldPosition pos) {
return toAppendTo.append(printer.format(obj));
}
/**
* 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.
*
* <p>
* The actual formatted length will almost always be less than or equal to this amount.
* </p>
*
* @return the maximum formatted length.
*/
public int getMaxLengthEstimate() {
return printer.getMaxLengthEstimate();
}
/**
* 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.
*
* <p>
* This zone is always used for {@link Date} formatting.
* </p>
*
* @return the time zone.
*/
@Override
public TimeZone getTimeZone() {
return printer.getTimeZone();
}
/**
* Returns a hash code compatible with equals.
*
* @return a hash code compatible with equals.
*/
@Override
public int hashCode() {
return printer.hashCode();
}
/*
* (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);
}
/**
* Gets a debugging string version of this formatter.
*
* @return a debug string.
*/
@Override
public String toString() {
return "FastDateFormat[" + printer.getPattern() + "," + printer.getLocale() + "," + printer.getTimeZone().getID() + "]";
}
}