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 org.sqlite.date; import java.io.IOException; import java.io.ObjectInputStream; import java.io.Serializable; import java.text.DateFormat; import java.text.DateFormatSymbols; import java.text.FieldPosition; import java.util.ArrayList; import java.util.Calendar; import java.util.Date; import java.util.GregorianCalendar; import java.util.List; import java.util.Locale; import java.util.TimeZone; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.ConcurrentMap; /** * <p>FastDatePrinter is a fast and thread-safe version of * {@link java.text.SimpleDateFormat}.</p> * * <p>To obtain a FastDatePrinter, use {@link FastDateFormat#getInstance(String, TimeZone, Locale)} * or another variation of the factory methods of {@link FastDateFormat}.</p> * * <p>Since FastDatePrinter is thread safe, you can use a static member instance:</p> * <code> * private static final DatePrinter DATE_PRINTER = FastDateFormat.getInstance("yyyy-MM-dd"); * </code> * * <p>This class can be used as a direct replacement to * {@code SimpleDateFormat} in most formatting 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> * * <p>Only formatting is supported by this class, but all patterns are compatible with * SimpleDateFormat (except time zones and some year patterns - see below).</p> * * <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> * * <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> * * <p>Starting with JDK7, ISO 8601 support was added using the pattern {@code 'X'}. * To maintain compatibility, {@code 'ZZ'} will continue to be supported, but using * one of the {@code 'X'} formats is recommended. * * <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. FastDatePrinter implements the behavior of Java 7.</p> * * @version $Id$ * @since 3.2 * @see FastDateParser */ public class FastDatePrinter implements DatePrinter, Serializable { // A lot of the speed in this class comes from caching, but some comes // from the special int to StringBuffer conversion. // // The following produces a padded 2 digit number: // buffer.append((char)(value / 10 + '0')); // buffer.append((char)(value % 10 + '0')); // // Note that the fastest append to StringBuffer is a single char (used here). // Note that Integer.toString() is not called, the conversion is simply // taking the value and adding (mathematically) the ASCII value for '0'. // So, don't change this code! It works and is very fast. /** * Required for serialization support. * * @see java.io.Serializable */ private static final long serialVersionUID = 1L; /** * 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; /** * The pattern. */ private final String mPattern; /** * The time zone. */ private final TimeZone mTimeZone; /** * The locale. */ private final Locale mLocale; /** * The parsed rules. */ private transient Rule[] mRules; /** * The estimated maximum length. */ private transient int mMaxLengthEstimate; // Constructor //----------------------------------------------------------------------- /** * <p>Constructs a new FastDatePrinter.</p> * Use {@link FastDateFormat#getInstance(String, TimeZone, Locale)} or another variation of the * factory methods of {@link FastDateFormat} to get a cached FastDatePrinter instance. * * @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 FastDatePrinter(final String pattern, final TimeZone timeZone, final Locale locale) { mPattern = pattern; mTimeZone = timeZone; mLocale = locale; init(); } /** * <p>Initializes the instance for first use.</p> */ private void init() { final List<Rule> rulesList = parsePattern(); mRules = rulesList.toArray(new Rule[rulesList.size()]); int len = 0; for (int i = mRules.length; --i >= 0;) { len += mRules[i].estimateLength(); } mMaxLengthEstimate = len; } // Parse the pattern //----------------------------------------------------------------------- /** * <p>Returns a list of Rules given a pattern.</p> * * @return a {@code List} of Rule objects * @throws IllegalArgumentException if pattern is invalid */ protected List<Rule> parsePattern() { final DateFormatSymbols symbols = new DateFormatSymbols(mLocale); final List<Rule> rules = new ArrayList<Rule>(); final String[] ERAs = symbols.getEras(); final String[] months = symbols.getMonths(); final String[] shortMonths = symbols.getShortMonths(); final String[] weekdays = symbols.getWeekdays(); final String[] shortWeekdays = symbols.getShortWeekdays(); final String[] AmPmStrings = symbols.getAmPmStrings(); final int length = mPattern.length(); final int[] indexRef = new int[1]; for (int i = 0; i < length; i++) { indexRef[0] = i; final String token = parseToken(mPattern, indexRef); i = indexRef[0]; final int tokenLen = token.length(); if (tokenLen == 0) { break; } Rule rule; final char c = token.charAt(0); switch (c) { case 'G': // era designator (text) rule = new TextField(Calendar.ERA, ERAs); break; case 'y': // year (number) if (tokenLen == 2) { rule = TwoDigitYearField.INSTANCE; } else { rule = selectNumberRule(Calendar.YEAR, tokenLen < 4 ? 4 : tokenLen); } break; case 'M': // month in year (text and number) if (tokenLen >= 4) { rule = new TextField(Calendar.MONTH, months); } else if (tokenLen == 3) { rule = new TextField(Calendar.MONTH, shortMonths); } else if (tokenLen == 2) { rule = TwoDigitMonthField.INSTANCE; } else { rule = UnpaddedMonthField.INSTANCE; } break; case 'd': // day in month (number) rule = selectNumberRule(Calendar.DAY_OF_MONTH, tokenLen); break; case 'h': // hour in am/pm (number, 1..12) rule = new TwelveHourField(selectNumberRule(Calendar.HOUR, tokenLen)); break; case 'H': // hour in day (number, 0..23) rule = selectNumberRule(Calendar.HOUR_OF_DAY, tokenLen); break; case 'm': // minute in hour (number) rule = selectNumberRule(Calendar.MINUTE, tokenLen); break; case 's': // second in minute (number) rule = selectNumberRule(Calendar.SECOND, tokenLen); break; case 'S': // millisecond (number) rule = selectNumberRule(Calendar.MILLISECOND, tokenLen); break; case 'E': // day in week (text) rule = new TextField(Calendar.DAY_OF_WEEK, tokenLen < 4 ? shortWeekdays : weekdays); break; case 'D': // day in year (number) rule = selectNumberRule(Calendar.DAY_OF_YEAR, tokenLen); break; case 'F': // day of week in month (number) rule = selectNumberRule(Calendar.DAY_OF_WEEK_IN_MONTH, tokenLen); break; case 'w': // week in year (number) rule = selectNumberRule(Calendar.WEEK_OF_YEAR, tokenLen); break; case 'W': // week in month (number) rule = selectNumberRule(Calendar.WEEK_OF_MONTH, tokenLen); break; case 'a': // am/pm marker (text) rule = new TextField(Calendar.AM_PM, AmPmStrings); break; case 'k': // hour in day (1..24) rule = new TwentyFourHourField(selectNumberRule(Calendar.HOUR_OF_DAY, tokenLen)); break; case 'K': // hour in am/pm (0..11) rule = selectNumberRule(Calendar.HOUR, tokenLen); break; case 'X': // ISO 8601 rule = Iso8601_Rule.getRule(tokenLen); break; case 'z': // time zone (text) if (tokenLen >= 4) { rule = new TimeZoneNameRule(mTimeZone, mLocale, TimeZone.LONG); } else { rule = new TimeZoneNameRule(mTimeZone, mLocale, TimeZone.SHORT); } break; case 'Z': // time zone (value) if (tokenLen == 1) { rule = TimeZoneNumberRule.INSTANCE_NO_COLON; } else if (tokenLen == 2) { rule = TimeZoneNumberRule.INSTANCE_ISO_8601; } else { rule = TimeZoneNumberRule.INSTANCE_COLON; } break; case '\'': // literal text final String sub = token.substring(1); if (sub.length() == 1) { rule = new CharacterLiteral(sub.charAt(0)); } else { rule = new StringLiteral(sub); } break; default: throw new IllegalArgumentException("Illegal pattern component: " + token); } rules.add(rule); } return rules; } /** * <p>Performs the parsing of tokens.</p> * * @param pattern the pattern * @param indexRef index references * @return parsed token */ protected String parseToken(final String pattern, final int[] indexRef) { final StringBuilder buf = new StringBuilder(); int i = indexRef[0]; final int length = pattern.length(); char c = pattern.charAt(i); if (c >= 'A' && c <= 'Z' || c >= 'a' && c <= 'z') { // Scan a run of the same character, which indicates a time // pattern. buf.append(c); while (i + 1 < length) { final char peek = pattern.charAt(i + 1); if (peek == c) { buf.append(c); i++; } else { break; } } } else { // This will identify token as text. buf.append('\''); boolean inLiteral = false; for (; i < length; i++) { c = pattern.charAt(i); if (c == '\'') { if (i + 1 < length && pattern.charAt(i + 1) == '\'') { // '' is treated as escaped ' i++; buf.append(c); } else { inLiteral = !inLiteral; } } else if (!inLiteral && (c >= 'A' && c <= 'Z' || c >= 'a' && c <= 'z')) { i--; break; } else { buf.append(c); } } } indexRef[0] = i; return buf.toString(); } /** * <p>Gets an appropriate rule for the padding required.</p> * * @param field the field to get a rule for * @param padding the padding required * @return a new rule with the correct padding */ protected NumberRule selectNumberRule(final int field, final int padding) { switch (padding) { case 1: return new UnpaddedNumberField(field); case 2: return new TwoDigitNumberField(field); default: return new PaddedNumberField(field, padding); } } // Format methods //----------------------------------------------------------------------- /** * <p>Formats a {@code Date}, {@code Calendar} or * {@code Long} (milliseconds) object.</p> * * @param obj the object to format * @param toAppendTo the buffer to append to * @param pos the position - ignored * @return the buffer passed in */ public StringBuffer format(final Object obj, final StringBuffer toAppendTo, final FieldPosition pos) { if (obj instanceof Date) { return format((Date) obj, toAppendTo); } else if (obj instanceof Calendar) { return format((Calendar) obj, toAppendTo); } else if (obj instanceof Long) { return format(((Long) obj).longValue(), toAppendTo); } else { throw new IllegalArgumentException( "Unknown class: " + (obj == null ? "<null>" : obj.getClass().getName())); } } /* (non-Javadoc) * @see org.apache.commons.lang3.time.DatePrinter#format(long) */ public String format(final long millis) { final Calendar c = newCalendar(); // hard code GregorianCalendar c.setTimeInMillis(millis); return applyRulesToString(c); } /** * Creates a String representation of the given Calendar by applying the rules of this printer to it. * @param c the Calender to apply the rules to. * @return a String representation of the given Calendar. */ private String applyRulesToString(final Calendar c) { return applyRules(c, new StringBuffer(mMaxLengthEstimate)).toString(); } /** * Creation method for ne calender instances. * @return a new Calendar instance. */ private GregorianCalendar newCalendar() { // hard code GregorianCalendar return new GregorianCalendar(mTimeZone, mLocale); } /* (non-Javadoc) * @see org.apache.commons.lang3.time.DatePrinter#format(java.util.Date) */ public String format(final Date date) { final Calendar c = newCalendar(); // hard code GregorianCalendar c.setTime(date); return applyRulesToString(c); } /* (non-Javadoc) * @see org.apache.commons.lang3.time.DatePrinter#format(java.util.Calendar) */ public String format(final Calendar calendar) { return format(calendar, new StringBuffer(mMaxLengthEstimate)).toString(); } /* (non-Javadoc) * @see org.apache.commons.lang3.time.DatePrinter#format(long, java.lang.StringBuffer) */ public StringBuffer format(final long millis, final StringBuffer buf) { return format(new Date(millis), buf); } /* (non-Javadoc) * @see org.apache.commons.lang3.time.DatePrinter#format(java.util.Date, java.lang.StringBuffer) */ public StringBuffer format(final Date date, final StringBuffer buf) { final Calendar c = newCalendar(); // hard code GregorianCalendar c.setTime(date); return applyRules(c, buf); } /* (non-Javadoc) * @see org.apache.commons.lang3.time.DatePrinter#format(java.util.Calendar, java.lang.StringBuffer) */ public StringBuffer format(final Calendar calendar, final StringBuffer buf) { return applyRules(calendar, buf); } /** * <p>Performs the formatting by applying the rules to the * specified calendar.</p> * * @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) { for (final Rule rule : mRules) { rule.appendTo(buf, calendar); } return buf; } // Accessors //----------------------------------------------------------------------- /* (non-Javadoc) * @see org.apache.commons.lang3.time.DatePrinter#getPattern() */ public String getPattern() { return mPattern; } /* (non-Javadoc) * @see org.apache.commons.lang3.time.DatePrinter#getTimeZone() */ public TimeZone getTimeZone() { return mTimeZone; } /* (non-Javadoc) * @see org.apache.commons.lang3.time.DatePrinter#getLocale() */ public Locale getLocale() { return mLocale; } /** * <p>Gets an estimate for the maximum string length that the * formatter will produce.</p> * * <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 mMaxLengthEstimate; } // Basics //----------------------------------------------------------------------- /** * <p>Compares two objects for equality.</p> * * @param obj the object to compare to * @return {@code true} if equal */ @Override public boolean equals(final Object obj) { if (obj instanceof FastDatePrinter == false) { return false; } final FastDatePrinter other = (FastDatePrinter) obj; return mPattern.equals(other.mPattern) && mTimeZone.equals(other.mTimeZone) && mLocale.equals(other.mLocale); } /** * <p>Returns a hashcode compatible with equals.</p> * * @return a hashcode compatible with equals */ @Override public int hashCode() { return mPattern.hashCode() + 13 * (mTimeZone.hashCode() + 13 * mLocale.hashCode()); } /** * <p>Gets a debugging string version of this formatter.</p> * * @return a debugging string */ @Override public String toString() { return "FastDatePrinter[" + mPattern + "," + mLocale + "," + mTimeZone.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(); init(); } /** * Appends digits to the given buffer. * * @param buffer the buffer to append to. * @param value the value to append digits from. */ private static void appendDigits(final StringBuffer buffer, final int value) { buffer.append((char) (value / 10 + '0')); buffer.append((char) (value % 10 + '0')); } // Rules //----------------------------------------------------------------------- /** * <p>Inner class defining a rule.</p> */ private interface Rule { /** * Returns the estimated length of the result. * * @return the estimated length */ int estimateLength(); /** * Appends the value of the specified calendar to the output buffer based on the rule implementation. * * @param buffer the output buffer * @param calendar calendar to be appended */ void appendTo(StringBuffer buffer, Calendar calendar); } /** * <p>Inner class defining a numeric rule.</p> */ private interface NumberRule extends Rule { /** * Appends the specified value to the output buffer based on the rule implementation. * * @param buffer the output buffer * @param value the value to be appended */ void appendTo(StringBuffer buffer, int value); } /** * <p>Inner class to output a constant single character.</p> */ private static class CharacterLiteral implements Rule { private final char mValue; /** * Constructs a new instance of {@code CharacterLiteral} * to hold the specified value. * * @param value the character literal */ CharacterLiteral(final char value) { mValue = value; } /** * {@inheritDoc} */ public int estimateLength() { return 1; } /** * {@inheritDoc} */ public void appendTo(final StringBuffer buffer, final Calendar calendar) { buffer.append(mValue); } } /** * <p>Inner class to output a constant string.</p> */ private static class StringLiteral implements Rule { private final String mValue; /** * Constructs a new instance of {@code StringLiteral} * to hold the specified value. * * @param value the string literal */ StringLiteral(final String value) { mValue = value; } /** * {@inheritDoc} */ public int estimateLength() { return mValue.length(); } /** * {@inheritDoc} */ public void appendTo(final StringBuffer buffer, final Calendar calendar) { buffer.append(mValue); } } /** * <p>Inner class to output one of a set of values.</p> */ private static class TextField implements Rule { private final int mField; private final String[] mValues; /** * Constructs an instance of {@code TextField} * with the specified field and values. * * @param field the field * @param values the field values */ TextField(final int field, final String[] values) { mField = field; mValues = values; } /** * {@inheritDoc} */ public int estimateLength() { int max = 0; for (int i = mValues.length; --i >= 0;) { final int len = mValues[i].length(); if (len > max) { max = len; } } return max; } /** * {@inheritDoc} */ public void appendTo(final StringBuffer buffer, final Calendar calendar) { buffer.append(mValues[calendar.get(mField)]); } } /** * <p>Inner class to output an unpadded number.</p> */ private static class UnpaddedNumberField implements NumberRule { private final int mField; /** * Constructs an instance of {@code UnpadedNumberField} with the specified field. * * @param field the field */ UnpaddedNumberField(final int field) { mField = field; } /** * {@inheritDoc} */ public int estimateLength() { return 4; } /** * {@inheritDoc} */ public void appendTo(final StringBuffer buffer, final Calendar calendar) { appendTo(buffer, calendar.get(mField)); } /** * {@inheritDoc} */ public final void appendTo(final StringBuffer buffer, final int value) { if (value < 10) { buffer.append((char) (value + '0')); } else if (value < 100) { appendDigits(buffer, value); } else { buffer.append(value); } } } /** * <p>Inner class to output an unpadded month.</p> */ private static class UnpaddedMonthField implements NumberRule { static final UnpaddedMonthField INSTANCE = new UnpaddedMonthField(); /** * Constructs an instance of {@code UnpaddedMonthField}. * */ UnpaddedMonthField() { super(); } /** * {@inheritDoc} */ public int estimateLength() { return 2; } /** * {@inheritDoc} */ public void appendTo(final StringBuffer buffer, final Calendar calendar) { appendTo(buffer, calendar.get(Calendar.MONTH) + 1); } /** * {@inheritDoc} */ public final void appendTo(final StringBuffer buffer, final int value) { if (value < 10) { buffer.append((char) (value + '0')); } else { appendDigits(buffer, value); } } } /** * <p>Inner class to output a padded number.</p> */ private static class PaddedNumberField implements NumberRule { private final int mField; private final int mSize; /** * Constructs an instance of {@code PaddedNumberField}. * * @param field the field * @param size size of the output field */ PaddedNumberField(final int field, final int size) { if (size < 3) { // Should use UnpaddedNumberField or TwoDigitNumberField. throw new IllegalArgumentException(); } mField = field; mSize = size; } /** * {@inheritDoc} */ public int estimateLength() { return mSize; } /** * {@inheritDoc} */ public void appendTo(final StringBuffer buffer, final Calendar calendar) { appendTo(buffer, calendar.get(mField)); } /** * {@inheritDoc} */ public final void appendTo(final StringBuffer buffer, int value) { // pad the buffer with adequate zeros for (int digit = 0; digit < mSize; ++digit) { buffer.append('0'); } // backfill the buffer with non-zero digits int index = buffer.length(); for (; value > 0; value /= 10) { buffer.setCharAt(--index, (char) ('0' + value % 10)); } } } /** * <p>Inner class to output a two digit number.</p> */ private static class TwoDigitNumberField implements NumberRule { private final int mField; /** * Constructs an instance of {@code TwoDigitNumberField} with the specified field. * * @param field the field */ TwoDigitNumberField(final int field) { mField = field; } /** * {@inheritDoc} */ public int estimateLength() { return 2; } /** * {@inheritDoc} */ public void appendTo(final StringBuffer buffer, final Calendar calendar) { appendTo(buffer, calendar.get(mField)); } /** * {@inheritDoc} */ public final void appendTo(final StringBuffer buffer, final int value) { if (value < 100) { appendDigits(buffer, value); } else { buffer.append(value); } } } /** * <p>Inner class to output a two digit year.</p> */ private static class TwoDigitYearField implements NumberRule { static final TwoDigitYearField INSTANCE = new TwoDigitYearField(); /** * Constructs an instance of {@code TwoDigitYearField}. */ TwoDigitYearField() { super(); } /** * {@inheritDoc} */ public int estimateLength() { return 2; } /** * {@inheritDoc} */ public void appendTo(final StringBuffer buffer, final Calendar calendar) { appendTo(buffer, calendar.get(Calendar.YEAR) % 100); } /** * {@inheritDoc} */ public final void appendTo(final StringBuffer buffer, final int value) { appendDigits(buffer, value); } } /** * <p>Inner class to output a two digit month.</p> */ private static class TwoDigitMonthField implements NumberRule { static final TwoDigitMonthField INSTANCE = new TwoDigitMonthField(); /** * Constructs an instance of {@code TwoDigitMonthField}. */ TwoDigitMonthField() { super(); } /** * {@inheritDoc} */ public int estimateLength() { return 2; } /** * {@inheritDoc} */ public void appendTo(final StringBuffer buffer, final Calendar calendar) { appendTo(buffer, calendar.get(Calendar.MONTH) + 1); } /** * {@inheritDoc} */ public final void appendTo(final StringBuffer buffer, final int value) { appendDigits(buffer, value); } } /** * <p>Inner class to output the twelve hour field.</p> */ private static class TwelveHourField implements NumberRule { private final NumberRule mRule; /** * Constructs an instance of {@code TwelveHourField} with the specified * {@code NumberRule}. * * @param rule the rule */ TwelveHourField(final NumberRule rule) { mRule = rule; } /** * {@inheritDoc} */ public int estimateLength() { return mRule.estimateLength(); } /** * {@inheritDoc} */ public void appendTo(final StringBuffer buffer, final Calendar calendar) { int value = calendar.get(Calendar.HOUR); if (value == 0) { value = calendar.getLeastMaximum(Calendar.HOUR) + 1; } mRule.appendTo(buffer, value); } /** * {@inheritDoc} */ public void appendTo(final StringBuffer buffer, final int value) { mRule.appendTo(buffer, value); } } /** * <p>Inner class to output the twenty four hour field.</p> */ private static class TwentyFourHourField implements NumberRule { private final NumberRule mRule; /** * Constructs an instance of {@code TwentyFourHourField} with the specified * {@code NumberRule}. * * @param rule the rule */ TwentyFourHourField(final NumberRule rule) { mRule = rule; } /** * {@inheritDoc} */ public int estimateLength() { return mRule.estimateLength(); } /** * {@inheritDoc} */ public void appendTo(final StringBuffer buffer, final Calendar calendar) { int value = calendar.get(Calendar.HOUR_OF_DAY); if (value == 0) { value = calendar.getMaximum(Calendar.HOUR_OF_DAY) + 1; } mRule.appendTo(buffer, value); } /** * {@inheritDoc} */ public void appendTo(final StringBuffer buffer, final int value) { mRule.appendTo(buffer, value); } } //----------------------------------------------------------------------- private static final ConcurrentMap<TimeZoneDisplayKey, String> cTimeZoneDisplayCache = new ConcurrentHashMap<TimeZoneDisplayKey, String>( 7); /** * <p>Gets the time zone display name, using a cache for performance.</p> * * @param tz the zone to query * @param daylight true if daylight savings * @param style the style to use {@code TimeZone.LONG} or {@code TimeZone.SHORT} * @param locale the locale to use * @return the textual name of the time zone */ static String getTimeZoneDisplay(final TimeZone tz, final boolean daylight, final int style, final Locale locale) { final TimeZoneDisplayKey key = new TimeZoneDisplayKey(tz, daylight, style, locale); String value = cTimeZoneDisplayCache.get(key); if (value == null) { // This is a very slow call, so cache the results. value = tz.getDisplayName(daylight, style, locale); final String prior = cTimeZoneDisplayCache.putIfAbsent(key, value); if (prior != null) { value = prior; } } return value; } /** * <p>Inner class to output a time zone name.</p> */ private static class TimeZoneNameRule implements Rule { private final Locale mLocale; private final int mStyle; private final String mStandard; private final String mDaylight; /** * Constructs an instance of {@code TimeZoneNameRule} with the specified properties. * * @param timeZone the time zone * @param locale the locale * @param style the style */ TimeZoneNameRule(final TimeZone timeZone, final Locale locale, final int style) { mLocale = locale; mStyle = style; mStandard = getTimeZoneDisplay(timeZone, false, style, locale); mDaylight = getTimeZoneDisplay(timeZone, true, style, locale); } /** * {@inheritDoc} */ public int estimateLength() { // We have no access to the Calendar object that will be passed to // appendTo so base estimate on the TimeZone passed to the // constructor return Math.max(mStandard.length(), mDaylight.length()); } /** * {@inheritDoc} */ public void appendTo(final StringBuffer buffer, final Calendar calendar) { final TimeZone zone = calendar.getTimeZone(); if (calendar.get(Calendar.DST_OFFSET) != 0) { buffer.append(getTimeZoneDisplay(zone, true, mStyle, mLocale)); } else { buffer.append(getTimeZoneDisplay(zone, false, mStyle, mLocale)); } } } /** * <p>Inner class to output a time zone as a number {@code +/-HHMM} * or {@code +/-HH:MM}.</p> */ private static class TimeZoneNumberRule implements Rule { static final TimeZoneNumberRule INSTANCE_COLON = new TimeZoneNumberRule(true, false); static final TimeZoneNumberRule INSTANCE_NO_COLON = new TimeZoneNumberRule(false, false); static final TimeZoneNumberRule INSTANCE_ISO_8601 = new TimeZoneNumberRule(true, true); final boolean mColon; final boolean mISO8601; /** * Constructs an instance of {@code TimeZoneNumberRule} with the specified properties. * * @param colon add colon between HH and MM in the output if {@code true} * @param iso8601 create an ISO 8601 format output */ TimeZoneNumberRule(final boolean colon, final boolean iso8601) { mColon = colon; mISO8601 = iso8601; } /** * {@inheritDoc} */ public int estimateLength() { return 5; } /** * {@inheritDoc} */ public void appendTo(final StringBuffer buffer, final Calendar calendar) { if (mISO8601 && calendar.getTimeZone().getID().equals("UTC")) { buffer.append("Z"); return; } int offset = calendar.get(Calendar.ZONE_OFFSET) + calendar.get(Calendar.DST_OFFSET); if (offset < 0) { buffer.append('-'); offset = -offset; } else { buffer.append('+'); } final int hours = offset / (60 * 60 * 1000); appendDigits(buffer, hours); if (mColon) { buffer.append(':'); } final int minutes = offset / (60 * 1000) - 60 * hours; appendDigits(buffer, minutes); } } /** * <p>Inner class to output a time zone as a number {@code +/-HHMM} * or {@code +/-HH:MM}.</p> */ private static class Iso8601_Rule implements Rule { // Sign TwoDigitHours or Z static final Iso8601_Rule ISO8601_HOURS = new Iso8601_Rule(3); // Sign TwoDigitHours Minutes or Z static final Iso8601_Rule ISO8601_HOURS_MINUTES = new Iso8601_Rule(5); // Sign TwoDigitHours : Minutes or Z static final Iso8601_Rule ISO8601_HOURS_COLON_MINUTES = new Iso8601_Rule(6); /** * Factory method for Iso8601_Rules. * * @param tokenLen a token indicating the length of the TimeZone String to be formatted. * @return a Iso8601_Rule that can format TimeZone String of length {@code tokenLen}. If no such * rule exists, an IllegalArgumentException will be thrown. */ static Iso8601_Rule getRule(int tokenLen) { switch (tokenLen) { case 1: return Iso8601_Rule.ISO8601_HOURS; case 2: return Iso8601_Rule.ISO8601_HOURS_MINUTES; case 3: return Iso8601_Rule.ISO8601_HOURS_COLON_MINUTES; default: throw new IllegalArgumentException("invalid number of X"); } } final int length; /** * Constructs an instance of {@code Iso8601_Rule} with the specified properties. * * @param length The number of characters in output (unless Z is output) */ Iso8601_Rule(final int length) { this.length = length; } /** * {@inheritDoc} */ public int estimateLength() { return length; } /** * {@inheritDoc} */ public void appendTo(final StringBuffer buffer, final Calendar calendar) { int zoneOffset = calendar.get(Calendar.ZONE_OFFSET); if (zoneOffset == 0) { buffer.append("Z"); return; } int offset = zoneOffset + calendar.get(Calendar.DST_OFFSET); if (offset < 0) { buffer.append('-'); offset = -offset; } else { buffer.append('+'); } final int hours = offset / (60 * 60 * 1000); appendDigits(buffer, hours); if (length < 5) { return; } if (length == 6) { buffer.append(':'); } final int minutes = offset / (60 * 1000) - 60 * hours; appendDigits(buffer, minutes); } } // ---------------------------------------------------------------------- /** * <p>Inner class that acts as a compound key for time zone names.</p> */ private static class TimeZoneDisplayKey { private final TimeZone mTimeZone; private final int mStyle; private final Locale mLocale; /** * Constructs an instance of {@code TimeZoneDisplayKey} with the specified properties. * * @param timeZone the time zone * @param daylight adjust the style for daylight saving time if {@code true} * @param style the timezone style * @param locale the timezone locale */ TimeZoneDisplayKey(final TimeZone timeZone, final boolean daylight, final int style, final Locale locale) { mTimeZone = timeZone; if (daylight) { mStyle = style | 0x80000000; } else { mStyle = style; } mLocale = locale; } /** * {@inheritDoc} */ @Override public int hashCode() { return (mStyle * 31 + mLocale.hashCode()) * 31 + mTimeZone.hashCode(); } /** * {@inheritDoc} */ @Override public boolean equals(final Object obj) { if (this == obj) { return true; } if (obj instanceof TimeZoneDisplayKey) { final TimeZoneDisplayKey other = (TimeZoneDisplayKey) obj; return mTimeZone.equals(other.mTimeZone) && mStyle == other.mStyle && mLocale.equals(other.mLocale); } return false; } } }