Java tutorial
/* * 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 com.application.utils; import java.io.IOException; import java.io.ObjectInputStream; import java.io.Serializable; import java.text.DateFormatSymbols; import java.text.ParseException; import java.text.ParsePosition; import java.util.ArrayList; import java.util.Calendar; import java.util.Date; import java.util.HashMap; import java.util.List; import java.util.Locale; import java.util.Map; import java.util.SortedMap; import java.util.TimeZone; import java.util.TreeMap; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.ConcurrentMap; import java.util.regex.Matcher; import java.util.regex.Pattern; /** * <p>FastDateParser is a fast and thread-safe version of * {@link java.text.SimpleDateFormat}.</p> * * <p>This class can be used as a direct replacement for * <code>SimpleDateFormat</code> in most parsing situations. * This class is especially useful in multi-threaded server environments. * <code>SimpleDateFormat</code> is not thread-safe in any JDK version, * nor will it be as Sun has closed the * <a href="http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4228335">bug</a>/RFE. * </p> * * <p>Only parsing is supported, but all patterns are compatible with * SimpleDateFormat.</p> * * <p>Timing tests indicate this class is as about as fast as SimpleDateFormat * in single thread applications and about 25% faster in multi-thread applications.</p> * * @version $Id: FastDateParser.java 1572877 2014-02-28 08:42:25Z britter $ * @since 3.2 */ public class FastDateParser implements DateParser, Serializable { /** * Required for serialization support. * * @see java.io.Serializable */ private static final long serialVersionUID = 2L; static final Locale JAPANESE_IMPERIAL = new Locale("ja", "JP", "JP"); // defining fields private final String pattern; private final TimeZone timeZone; private final Locale locale; private final int century; private final int startYear; // derived fields private transient Pattern parsePattern; private transient Strategy[] strategies; // dynamic fields to communicate with Strategy private transient String currentFormatField; private transient Strategy nextStrategy; /** * <p>Constructs a new FastDateParser.</p> * * @param pattern non-null {@link java.text.SimpleDateFormat} compatible * pattern * @param timeZone non-null time zone to use * @param locale non-null locale */ protected FastDateParser(final String pattern, final TimeZone timeZone, final Locale locale) { this(pattern, timeZone, locale, null); } /** * <p>Constructs a new FastDateParser.</p> * * @param pattern non-null {@link java.text.SimpleDateFormat} compatible * pattern * @param timeZone non-null time zone to use * @param locale non-null locale * @param centuryStart The start of the century for 2 digit year parsing * @since 3.3 */ protected FastDateParser(final String pattern, final TimeZone timeZone, final Locale locale, final Date centuryStart) { this.pattern = pattern; this.timeZone = timeZone; this.locale = locale; final Calendar definingCalendar = Calendar.getInstance(timeZone, locale); int centuryStartYear; if (centuryStart != null) { definingCalendar.setTime(centuryStart); centuryStartYear = definingCalendar.get(Calendar.YEAR); } else if (locale.equals(JAPANESE_IMPERIAL)) { centuryStartYear = 0; } else { // from 80 years ago to 20 years from now definingCalendar.setTime(new Date()); centuryStartYear = definingCalendar.get(Calendar.YEAR) - 80; } century = centuryStartYear / 100 * 100; startYear = centuryStartYear - century; init(definingCalendar); } /** * Initialize derived fields from defining fields. * This is called from constructor and from readObject (de-serialization) * * @param definingCalendar the {@link java.util.Calendar} instance used to initialize this FastDateParser */ private void init(Calendar definingCalendar) { final StringBuilder regex = new StringBuilder(); final List<Strategy> collector = new ArrayList<Strategy>(); final Matcher patternMatcher = formatPattern.matcher(pattern); if (!patternMatcher.lookingAt()) { throw new IllegalArgumentException( "Illegal pattern character '" + pattern.charAt(patternMatcher.regionStart()) + "'"); } currentFormatField = patternMatcher.group(); Strategy currentStrategy = getStrategy(currentFormatField, definingCalendar); for (;;) { patternMatcher.region(patternMatcher.end(), patternMatcher.regionEnd()); if (!patternMatcher.lookingAt()) { nextStrategy = null; break; } final String nextFormatField = patternMatcher.group(); nextStrategy = getStrategy(nextFormatField, definingCalendar); if (currentStrategy.addRegex(this, regex)) { collector.add(currentStrategy); } currentFormatField = nextFormatField; currentStrategy = nextStrategy; } if (patternMatcher.regionStart() != patternMatcher.regionEnd()) { throw new IllegalArgumentException( "Failed to parse \"" + pattern + "\" ; gave up at index " + patternMatcher.regionStart()); } if (currentStrategy.addRegex(this, regex)) { collector.add(currentStrategy); } currentFormatField = null; strategies = collector.toArray(new Strategy[collector.size()]); parsePattern = Pattern.compile(regex.toString()); } // Accessors //----------------------------------------------------------------------- /* (non-Javadoc) * @see org.apache.commons.lang3.time.DateParser#getPattern() */ @Override public String getPattern() { return pattern; } /* (non-Javadoc) * @see org.apache.commons.lang3.time.DateParser#getTimeZone() */ @Override public TimeZone getTimeZone() { return timeZone; } /* (non-Javadoc) * @see org.apache.commons.lang3.time.DateParser#getLocale() */ @Override public Locale getLocale() { return locale; } /** * Returns the generated pattern (for testing purposes). * * @return the generated pattern */ Pattern getParsePattern() { return parsePattern; } // Basics //----------------------------------------------------------------------- /** * <p>Compare another object for equality with this object.</p> * * @param obj the object to compare to * @return <code>true</code>if equal to this instance */ @Override public boolean equals(final Object obj) { if (!(obj instanceof FastDateParser)) { return false; } final FastDateParser other = (FastDateParser) obj; return pattern.equals(other.pattern) && timeZone.equals(other.timeZone) && locale.equals(other.locale); } /** * <p>Return a hashcode compatible with equals.</p> * * @return a hashcode compatible with equals */ @Override public int hashCode() { return pattern.hashCode() + 13 * (timeZone.hashCode() + 13 * locale.hashCode()); } /** * <p>Get a string version of this formatter.</p> * * @return a debugging string */ @Override public String toString() { return "FastDateParser[" + pattern + "," + locale + "," + timeZone.getID() + "]"; } // Serializing //----------------------------------------------------------------------- /** * Create the object after serialization. This implementation reinitializes the * transient properties. * * @param in ObjectInputStream from which the object is being deserialized. * @throws IOException if there is an IO issue. * @throws ClassNotFoundException if a class cannot be found. */ private void readObject(final ObjectInputStream in) throws IOException, ClassNotFoundException { in.defaultReadObject(); final Calendar definingCalendar = Calendar.getInstance(timeZone, locale); init(definingCalendar); } /* (non-Javadoc) * @see org.apache.commons.lang3.time.DateParser#parseObject(java.lang.String) */ @Override public Object parseObject(final String source) throws ParseException { return parse(source); } /* (non-Javadoc) * @see org.apache.commons.lang3.time.DateParser#parse(java.lang.String) */ @Override public Date parse(final String source) throws ParseException { final Date date = parse(source, new ParsePosition(0)); if (date == null) { // Add a note re supported date range if (locale.equals(JAPANESE_IMPERIAL)) { throw new ParseException( "(The " + locale + " locale does not support dates before 1868 AD)\n" + "Unparseable date: \"" + source + "\" does not match " + parsePattern.pattern(), 0); } throw new ParseException( "Unparseable date: \"" + source + "\" does not match " + parsePattern.pattern(), 0); } return date; } /* (non-Javadoc) * @see org.apache.commons.lang3.time.DateParser#parseObject(java.lang.String, java.text.ParsePosition) */ @Override public Object parseObject(final String source, final ParsePosition pos) { return parse(source, pos); } /* (non-Javadoc) * @see org.apache.commons.lang3.time.DateParser#parse(java.lang.String, java.text.ParsePosition) */ @Override public Date parse(final String source, final ParsePosition pos) { final int offset = pos.getIndex(); final Matcher matcher = parsePattern.matcher(source.substring(offset)); if (!matcher.lookingAt()) { return null; } // timing tests indicate getting new instance is 19% faster than cloning final Calendar cal = Calendar.getInstance(timeZone, locale); cal.clear(); for (int i = 0; i < strategies.length;) { final Strategy strategy = strategies[i++]; strategy.setCalendar(this, cal, matcher.group(i)); } pos.setIndex(offset + matcher.end()); return cal.getTime(); } // Support for strategies //----------------------------------------------------------------------- /** * Escape constant fields into regular expression * * @param regex The destination regex * @param value The source field * @param unquote If true, replace two success quotes ('') with single quote (') * @return The <code>StringBuilder</code> */ private static StringBuilder escapeRegex(final StringBuilder regex, final String value, final boolean unquote) { regex.append("\\Q"); for (int i = 0; i < value.length(); ++i) { char c = value.charAt(i); switch (c) { case '\'': if (unquote) { if (++i == value.length()) { return regex; } c = value.charAt(i); } break; case '\\': if (++i == value.length()) { break; } /* * If we have found \E, we replace it with \E\\E\Q, i.e. we stop the quoting, * quote the \ in \E, then restart the quoting. * * Otherwise we just output the two characters. * In each case the initial \ needs to be output and the final char is done at the end */ regex.append(c); // we always want the original \ c = value.charAt(i); // Is it followed by E ? if (c == 'E') { // \E detected regex.append("E\\\\E\\"); // see comment above c = 'Q'; // appended below } break; default: break; } regex.append(c); } regex.append("\\E"); return regex; } private static String[] getDisplayNameArray(int field, boolean isLong, Locale locale) { DateFormatSymbols dfs = new DateFormatSymbols(locale); switch (field) { case Calendar.AM_PM: return dfs.getAmPmStrings(); case Calendar.DAY_OF_WEEK: return isLong ? dfs.getWeekdays() : dfs.getShortWeekdays(); case Calendar.ERA: return dfs.getEras(); case Calendar.MONTH: return isLong ? dfs.getMonths() : dfs.getShortMonths(); } return null; } private static void insertValuesInMap(Map<String, Integer> map, String[] values) { if (values == null) { return; } for (int i = 0; i < values.length; ++i) { if (values[i] != null && values[i].length() > 0) { map.put(values[i], i); } } } private static Map<String, Integer> getDisplayNames(int field, Locale locale) { Map<String, Integer> result = new HashMap<String, Integer>(); insertValuesInMap(result, getDisplayNameArray(field, false, locale)); insertValuesInMap(result, getDisplayNameArray(field, true, locale)); return result.isEmpty() ? null : result; } /** * Get the short and long values displayed for a field * * @param field The field of interest * @param definingCalendar The calendar to obtain the short and long values * @param locale The locale of display names * @return A Map of the field key / value pairs */ private static Map<String, Integer> getDisplayNames(final int field, final Calendar definingCalendar, final Locale locale) { return getDisplayNames(field, locale); } /** * Adjust dates to be within appropriate century * * @param twoDigitYear The year to adjust * @return A value between centuryStart(inclusive) to centuryStart+100(exclusive) */ private int adjustYear(final int twoDigitYear) { int trial = century + twoDigitYear; return twoDigitYear >= startYear ? trial : trial + 100; } /** * Is the next field a number? * * @return true, if next field will be a number */ boolean isNextNumber() { return nextStrategy != null && nextStrategy.isNumber(); } /** * What is the width of the current field? * * @return The number of characters in the current format field */ int getFieldWidth() { return currentFormatField.length(); } /** * A strategy to parse a single field from the parsing pattern */ private static abstract class Strategy { /** * Is this field a number? * The default implementation returns false. * * @return true, if field is a number */ boolean isNumber() { return false; } /** * Set the Calendar with the parsed field. * <p/> * The default implementation does nothing. * * @param parser The parser calling this strategy * @param cal The <code>Calendar</code> to set * @param value The parsed field to translate and set in cal */ void setCalendar(final FastDateParser parser, final Calendar cal, final String value) { } /** * Generate a <code>Pattern</code> regular expression to the <code>StringBuilder</code> * which will accept this field * * @param parser The parser calling this strategy * @param regex The <code>StringBuilder</code> to append to * @return true, if this field will set the calendar; * false, if this field is a constant value */ abstract boolean addRegex(FastDateParser parser, StringBuilder regex); } /** * A <code>Pattern</code> to parse the user supplied SimpleDateFormat pattern */ private static final Pattern formatPattern = Pattern.compile( "D+|E+|F+|G+|H+|K+|M+|S+|W+|Z+|a+|d+|h+|k+|m+|s+|w+|y+|z+|''|'[^']++(''[^']*+)*+'|[^'A-Za-z]++"); /** * Obtain a Strategy given a field from a SimpleDateFormat pattern * * @param formatField A sub-sequence of the SimpleDateFormat pattern * @param definingCalendar The calendar to obtain the short and long values * @return The Strategy that will handle parsing for the field */ private Strategy getStrategy(final String formatField, final Calendar definingCalendar) { switch (formatField.charAt(0)) { case '\'': if (formatField.length() > 2) { return new CopyQuotedStrategy(formatField.substring(1, formatField.length() - 1)); } //$FALL-THROUGH$ default: return new CopyQuotedStrategy(formatField); case 'D': return DAY_OF_YEAR_STRATEGY; case 'E': return getLocaleSpecificStrategy(Calendar.DAY_OF_WEEK, definingCalendar); case 'F': return DAY_OF_WEEK_IN_MONTH_STRATEGY; case 'G': return getLocaleSpecificStrategy(Calendar.ERA, definingCalendar); case 'H': return MODULO_HOUR_OF_DAY_STRATEGY; case 'K': return HOUR_STRATEGY; case 'M': return formatField.length() >= 3 ? getLocaleSpecificStrategy(Calendar.MONTH, definingCalendar) : NUMBER_MONTH_STRATEGY; case 'S': return MILLISECOND_STRATEGY; case 'W': return WEEK_OF_MONTH_STRATEGY; case 'a': return getLocaleSpecificStrategy(Calendar.AM_PM, definingCalendar); case 'd': return DAY_OF_MONTH_STRATEGY; case 'h': return MODULO_HOUR_STRATEGY; case 'k': return HOUR_OF_DAY_STRATEGY; case 'm': return MINUTE_STRATEGY; case 's': return SECOND_STRATEGY; case 'w': return WEEK_OF_YEAR_STRATEGY; case 'y': return formatField.length() > 2 ? LITERAL_YEAR_STRATEGY : ABBREVIATED_YEAR_STRATEGY; case 'Z': case 'z': return getLocaleSpecificStrategy(Calendar.ZONE_OFFSET, definingCalendar); } } @SuppressWarnings("unchecked") // OK because we are creating an array with no entries private static final ConcurrentMap<Locale, Strategy>[] caches = new ConcurrentMap[Calendar.FIELD_COUNT]; /** * Get a cache of Strategies for a particular field * * @param field The Calendar field * @return a cache of Locale to Strategy */ private static ConcurrentMap<Locale, Strategy> getCache(final int field) { synchronized (caches) { if (caches[field] == null) { caches[field] = new ConcurrentHashMap<Locale, Strategy>(3); } return caches[field]; } } /** * Construct a Strategy that parses a Text field * * @param field The Calendar field * @param definingCalendar The calendar to obtain the short and long values * @return a TextStrategy for the field and Locale */ private Strategy getLocaleSpecificStrategy(final int field, final Calendar definingCalendar) { final ConcurrentMap<Locale, Strategy> cache = getCache(field); Strategy strategy = cache.get(locale); if (strategy == null) { strategy = field == Calendar.ZONE_OFFSET ? new TimeZoneStrategy(locale) : new TextStrategy(field, definingCalendar, locale); final Strategy inCache = cache.putIfAbsent(locale, strategy); if (inCache != null) { return inCache; } } return strategy; } /** * A strategy that copies the static or quoted field in the parsing pattern */ private static class CopyQuotedStrategy extends Strategy { private final String formatField; /** * Construct a Strategy that ensures the formatField has literal text * * @param formatField The literal text to match */ CopyQuotedStrategy(final String formatField) { this.formatField = formatField; } /** * {@inheritDoc} */ @Override boolean isNumber() { char c = formatField.charAt(0); if (c == '\'') { c = formatField.charAt(1); } return Character.isDigit(c); } /** * {@inheritDoc} */ @Override boolean addRegex(final FastDateParser parser, final StringBuilder regex) { escapeRegex(regex, formatField, true); return false; } } /** * A strategy that handles a text field in the parsing pattern */ private static class TextStrategy extends Strategy { private final int field; private final Map<String, Integer> keyValues; /** * Construct a Strategy that parses a Text field * * @param field The Calendar field * @param definingCalendar The Calendar to use * @param locale The Locale to use */ TextStrategy(final int field, final Calendar definingCalendar, final Locale locale) { this.field = field; this.keyValues = getDisplayNames(field, definingCalendar, locale); } /** * {@inheritDoc} */ @Override boolean addRegex(final FastDateParser parser, final StringBuilder regex) { regex.append('('); for (final String textKeyValue : keyValues.keySet()) { escapeRegex(regex, textKeyValue, false).append('|'); } regex.setCharAt(regex.length() - 1, ')'); return true; } /** * {@inheritDoc} */ @Override void setCalendar(final FastDateParser parser, final Calendar cal, final String value) { final Integer iVal = keyValues.get(value); if (iVal == null) { final StringBuilder sb = new StringBuilder(value); sb.append(" not in ("); for (final String textKeyValue : keyValues.keySet()) { sb.append(textKeyValue).append(' '); } sb.setCharAt(sb.length() - 1, ')'); throw new IllegalArgumentException(sb.toString()); } cal.set(field, iVal.intValue()); } } /** * A strategy that handles a number field in the parsing pattern */ private static class NumberStrategy extends Strategy { private final int field; /** * Construct a Strategy that parses a Number field * * @param field The Calendar field */ NumberStrategy(final int field) { this.field = field; } /** * {@inheritDoc} */ @Override boolean isNumber() { return true; } /** * {@inheritDoc} */ @Override boolean addRegex(final FastDateParser parser, final StringBuilder regex) { // See LANG-954: We use {Nd} rather than {IsNd} because Android does not support the Is prefix if (parser.isNextNumber()) { regex.append("(\\p{Nd}{").append(parser.getFieldWidth()).append("}+)"); } else { regex.append("(\\p{Nd}++)"); } return true; } /** * {@inheritDoc} */ @Override void setCalendar(final FastDateParser parser, final Calendar cal, final String value) { cal.set(field, modify(Integer.parseInt(value))); } /** * Make any modifications to parsed integer * * @param iValue The parsed integer * @return The modified value */ int modify(final int iValue) { return iValue; } } private static final Strategy ABBREVIATED_YEAR_STRATEGY = new NumberStrategy(Calendar.YEAR) { /** * {@inheritDoc} */ @Override void setCalendar(final FastDateParser parser, final Calendar cal, final String value) { int iValue = Integer.parseInt(value); if (iValue < 100) { iValue = parser.adjustYear(iValue); } cal.set(Calendar.YEAR, iValue); } }; /** * A strategy that handles a timezone field in the parsing pattern */ private static class TimeZoneStrategy extends Strategy { private final String validTimeZoneChars; private final SortedMap<String, TimeZone> tzNames = new TreeMap<String, TimeZone>( String.CASE_INSENSITIVE_ORDER); /** * Index of zone id */ private static final int ID = 0; /** * Index of the long name of zone in standard time */ private static final int LONG_STD = 1; /** * Index of the short name of zone in standard time */ private static final int SHORT_STD = 2; /** * Index of the long name of zone in daylight saving time */ private static final int LONG_DST = 3; /** * Index of the short name of zone in daylight saving time */ private static final int SHORT_DST = 4; /** * Construct a Strategy that parses a TimeZone * * @param locale The Locale */ TimeZoneStrategy(final Locale locale) { final String[][] zones = DateFormatSymbols.getInstance(locale).getZoneStrings(); for (String[] zone : zones) { if (zone[ID].startsWith("GMT")) { continue; } final TimeZone tz = TimeZone.getTimeZone(zone[ID]); if (!tzNames.containsKey(zone[LONG_STD])) { tzNames.put(zone[LONG_STD], tz); } if (!tzNames.containsKey(zone[SHORT_STD])) { tzNames.put(zone[SHORT_STD], tz); } if (tz.useDaylightTime()) { if (!tzNames.containsKey(zone[LONG_DST])) { tzNames.put(zone[LONG_DST], tz); } if (!tzNames.containsKey(zone[SHORT_DST])) { tzNames.put(zone[SHORT_DST], tz); } } } final StringBuilder sb = new StringBuilder(); sb.append("(GMT[+\\-]\\d{0,1}\\d{2}|[+\\-]\\d{2}:?\\d{2}|"); for (final String id : tzNames.keySet()) { escapeRegex(sb, id, false).append('|'); } sb.setCharAt(sb.length() - 1, ')'); validTimeZoneChars = sb.toString(); } /** * {@inheritDoc} */ @Override boolean addRegex(final FastDateParser parser, final StringBuilder regex) { regex.append(validTimeZoneChars); return true; } /** * {@inheritDoc} */ @Override void setCalendar(final FastDateParser parser, final Calendar cal, final String value) { TimeZone tz; if (value.charAt(0) == '+' || value.charAt(0) == '-') { tz = TimeZone.getTimeZone("GMT" + value); } else if (value.startsWith("GMT")) { tz = TimeZone.getTimeZone(value); } else { tz = tzNames.get(value); if (tz == null) { throw new IllegalArgumentException(value + " is not a supported timezone name"); } } cal.setTimeZone(tz); } } private static final Strategy NUMBER_MONTH_STRATEGY = new NumberStrategy(Calendar.MONTH) { @Override int modify(final int iValue) { return iValue - 1; } }; private static final Strategy LITERAL_YEAR_STRATEGY = new NumberStrategy(Calendar.YEAR); private static final Strategy WEEK_OF_YEAR_STRATEGY = new NumberStrategy(Calendar.WEEK_OF_YEAR); private static final Strategy WEEK_OF_MONTH_STRATEGY = new NumberStrategy(Calendar.WEEK_OF_MONTH); private static final Strategy DAY_OF_YEAR_STRATEGY = new NumberStrategy(Calendar.DAY_OF_YEAR); private static final Strategy DAY_OF_MONTH_STRATEGY = new NumberStrategy(Calendar.DAY_OF_MONTH); private static final Strategy DAY_OF_WEEK_IN_MONTH_STRATEGY = new NumberStrategy(Calendar.DAY_OF_WEEK_IN_MONTH); private static final Strategy HOUR_OF_DAY_STRATEGY = new NumberStrategy(Calendar.HOUR_OF_DAY); private static final Strategy MODULO_HOUR_OF_DAY_STRATEGY = new NumberStrategy(Calendar.HOUR_OF_DAY) { @Override int modify(final int iValue) { return iValue % 24; } }; private static final Strategy MODULO_HOUR_STRATEGY = new NumberStrategy(Calendar.HOUR) { @Override int modify(final int iValue) { return iValue % 12; } }; private static final Strategy HOUR_STRATEGY = new NumberStrategy(Calendar.HOUR); private static final Strategy MINUTE_STRATEGY = new NumberStrategy(Calendar.MINUTE); private static final Strategy SECOND_STRATEGY = new NumberStrategy(Calendar.SECOND); private static final Strategy MILLISECOND_STRATEGY = new NumberStrategy(Calendar.MILLISECOND); }