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
*
* 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.sqlite.date;
import java.text.DateFormat;
import java.text.FieldPosition;
import java.text.Format;
import java.text.ParseException;
import java.text.ParsePosition;
import java.util.Calendar;
import java.util.Date;
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>Since FastDateFormat is thread safe, you can use a static member instance: <code>
* private static final FastDateFormat DATE_FORMATTER = FastDateFormat.getDateTimeInstance(FastDateFormat.LONG, FastDateFormat.SHORT);
* </code>
*
* <p>This class can be used as a direct replacement to {@code SimpleDateFormat} in most formatting
* and parsing situations. This class is especially useful in multi-threaded server environments.
* {@code SimpleDateFormat} is not thread-safe in any JDK version, nor will it be as Sun have closed
* the bug/RFE.
*
* <p>All patterns are compatible with SimpleDateFormat (except time zones and some year patterns -
* see below).
*
* <p>Since 3.2, FastDateFormat supports parsing as well as printing.
*
* <p>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).
*
* <p>In addition, the pattern {@code 'ZZ'} has been made to represent ISO 8601 full 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.
*
* <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.
*
* @since 2.0
* @version $Id$
*/
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<FastDateFormat> cache =
new FormatCache<FastDateFormat>() {
@Override
protected FastDateFormat createInstance(
final String pattern, final TimeZone timeZone, final Locale locale) {
return new FastDateFormat(pattern, timeZone, locale);
}
};
private final FastDatePrinter printer;
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 {@code Date}, {@code Calendar} or {@code Long} (milliseconds) object.
*
* @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 printer.format(obj, toAppendTo, pos);
}
/**
* Formats a millisecond {@code long} value.
*
* @param millis the millisecond value to format
* @return the formatted string
* @since 2.1
*/
public String format(final long millis) {
return printer.format(millis);
}
/**
* Formats a {@code Date} object using a {@code GregorianCalendar}.
*
* @param date the date to format
* @return the formatted string
*/
public String format(final Date date) {
return printer.format(date);
}
/**
* Formats a {@code Calendar} object.
*
* @param calendar the calendar to format
* @return the formatted string
*/
public String format(final Calendar calendar) {
return printer.format(calendar);
}
/**
* Formats a millisecond {@code long} value into the supplied {@code StringBuffer}.
*
* @param millis the millisecond value to format
* @param buf the buffer to format into
* @return the specified string buffer
* @since 2.1
*/
public StringBuffer format(final long millis, final StringBuffer buf) {
return printer.format(millis, buf);
}
/**
* Formats a {@code Date} object into the supplied {@code StringBuffer} using a {@code
* GregorianCalendar}.
*
* @param date the date to format
* @param buf the buffer to format into
* @return the specified string buffer
*/
public StringBuffer format(final Date date, final StringBuffer buf) {
return printer.format(date, buf);
}
/**
* Formats a {@code Calendar} object into the supplied {@code StringBuffer}.
*
* @param calendar the calendar to format
* @param buf the buffer to format into
* @return the specified string buffer
*/
public StringBuffer format(final Calendar calendar, final StringBuffer buf) {
return printer.format(calendar, buf);
}
// Parsing
// -----------------------------------------------------------------------
/* (non-Javadoc)
* @see DateParser#parse(java.lang.String)
*/
public Date parse(final String source) throws ParseException {
return parser.parse(source);
}
/* (non-Javadoc)
* @see DateParser#parse(java.lang.String, java.text.ParsePosition)
*/
public Date parse(final String source, final ParsePosition pos) {
return parser.parse(source, pos);
}
/* (non-Javadoc)
* @see java.text.Format#parseObject(java.lang.String, java.text.ParsePosition)
*/
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
*/
public String getPattern() {
return printer.getPattern();
}
/**
* Gets the time zone used by this formatter.
*
* <p>This zone is always used for {@code Date} formatting.
*
* @return the time zone
*/
public TimeZone getTimeZone() {
return printer.getTimeZone();
}
/**
* Gets the locale used by this formatter.
*
* @return the locale
*/
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.
*
* @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 == false) {
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 hashcode compatible with equals.
*
* @return a hashcode 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
*/
protected StringBuffer applyRules(final Calendar calendar, final StringBuffer buf) {
return printer.applyRules(calendar, buf);
}
}