+++ /dev/null
-package org.apache.lucene.document;
-
-/**
- * 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.
- */
-
-import org.apache.lucene.search.NumericRangeQuery; // for javadocs
-import org.apache.lucene.util.NumericUtils; // for javadocs
-
-import java.text.ParseException;
-import java.text.SimpleDateFormat;
-import java.util.Calendar;
-import java.util.Date;
-import java.util.Locale;
-import java.util.TimeZone;
-
-/**
- * Provides support for converting dates to strings and vice-versa.
- * The strings are structured so that lexicographic sorting orders
- * them by date, which makes them suitable for use as field values
- * and search terms.
- *
- * <P>This class also helps you to limit the resolution of your dates. Do not
- * save dates with a finer resolution than you really need, as then
- * RangeQuery and PrefixQuery will require more memory and become slower.
- *
- * <P>Compared to {@link DateField} the strings generated by the methods
- * in this class take slightly more space, unless your selected resolution
- * is set to <code>Resolution.DAY</code> or lower.
- *
- * <P>
- * Another approach is {@link NumericUtils}, which provides
- * a sortable binary representation (prefix encoded) of numeric values, which
- * date/time are.
- * For indexing a {@link Date} or {@link Calendar}, just get the unix timestamp as
- * <code>long</code> using {@link Date#getTime} or {@link Calendar#getTimeInMillis} and
- * index this as a numeric value with {@link NumericField}
- * and use {@link NumericRangeQuery} to query it.
- */
-public class DateTools {
-
- final static TimeZone GMT = TimeZone.getTimeZone("GMT");
-
- private static final ThreadLocal<Calendar> TL_CAL = new ThreadLocal<Calendar>() {
- @Override
- protected Calendar initialValue() {
- return Calendar.getInstance(GMT, Locale.US);
- }
- };
-
- //indexed by format length
- private static final ThreadLocal<SimpleDateFormat[]> TL_FORMATS = new ThreadLocal<SimpleDateFormat[]>() {
- @Override
- protected SimpleDateFormat[] initialValue() {
- SimpleDateFormat[] arr = new SimpleDateFormat[Resolution.MILLISECOND.formatLen+1];
- for (Resolution resolution : Resolution.values()) {
- arr[resolution.formatLen] = (SimpleDateFormat)resolution.format.clone();
- }
- return arr;
- }
- };
-
- // cannot create, the class has static methods only
- private DateTools() {}
-
- /**
- * Converts a Date to a string suitable for indexing.
- *
- * @param date the date to be converted
- * @param resolution the desired resolution, see
- * {@link #round(Date, DateTools.Resolution)}
- * @return a string in format <code>yyyyMMddHHmmssSSS</code> or shorter,
- * depending on <code>resolution</code>; using GMT as timezone
- */
- public static String dateToString(Date date, Resolution resolution) {
- return timeToString(date.getTime(), resolution);
- }
-
- /**
- * Converts a millisecond time to a string suitable for indexing.
- *
- * @param time the date expressed as milliseconds since January 1, 1970, 00:00:00 GMT
- * @param resolution the desired resolution, see
- * {@link #round(long, DateTools.Resolution)}
- * @return a string in format <code>yyyyMMddHHmmssSSS</code> or shorter,
- * depending on <code>resolution</code>; using GMT as timezone
- */
- public static String timeToString(long time, Resolution resolution) {
- final Date date = new Date(round(time, resolution));
- return TL_FORMATS.get()[resolution.formatLen].format(date);
- }
-
- /**
- * Converts a string produced by <code>timeToString</code> or
- * <code>dateToString</code> back to a time, represented as the
- * number of milliseconds since January 1, 1970, 00:00:00 GMT.
- *
- * @param dateString the date string to be converted
- * @return the number of milliseconds since January 1, 1970, 00:00:00 GMT
- * @throws ParseException if <code>dateString</code> is not in the
- * expected format
- */
- public static long stringToTime(String dateString) throws ParseException {
- return stringToDate(dateString).getTime();
- }
-
- /**
- * Converts a string produced by <code>timeToString</code> or
- * <code>dateToString</code> back to a time, represented as a
- * Date object.
- *
- * @param dateString the date string to be converted
- * @return the parsed time as a Date object
- * @throws ParseException if <code>dateString</code> is not in the
- * expected format
- */
- public static Date stringToDate(String dateString) throws ParseException {
- try {
- return TL_FORMATS.get()[dateString.length()].parse(dateString);
- } catch (Exception e) {
- throw new ParseException("Input is not a valid date string: " + dateString, 0);
- }
- }
-
- /**
- * Limit a date's resolution. For example, the date <code>2004-09-21 13:50:11</code>
- * will be changed to <code>2004-09-01 00:00:00</code> when using
- * <code>Resolution.MONTH</code>.
- *
- * @param resolution The desired resolution of the date to be returned
- * @return the date with all values more precise than <code>resolution</code>
- * set to 0 or 1
- */
- public static Date round(Date date, Resolution resolution) {
- return new Date(round(date.getTime(), resolution));
- }
-
- /**
- * Limit a date's resolution. For example, the date <code>1095767411000</code>
- * (which represents 2004-09-21 13:50:11) will be changed to
- * <code>1093989600000</code> (2004-09-01 00:00:00) when using
- * <code>Resolution.MONTH</code>.
- *
- * @param resolution The desired resolution of the date to be returned
- * @return the date with all values more precise than <code>resolution</code>
- * set to 0 or 1, expressed as milliseconds since January 1, 1970, 00:00:00 GMT
- */
- @SuppressWarnings("fallthrough")
- public static long round(long time, Resolution resolution) {
- final Calendar calInstance = TL_CAL.get();
- calInstance.setTimeInMillis(time);
-
- switch (resolution) {
- //NOTE: switch statement fall-through is deliberate
- case YEAR:
- calInstance.set(Calendar.MONTH, 0);
- case MONTH:
- calInstance.set(Calendar.DAY_OF_MONTH, 1);
- case DAY:
- calInstance.set(Calendar.HOUR_OF_DAY, 0);
- case HOUR:
- calInstance.set(Calendar.MINUTE, 0);
- case MINUTE:
- calInstance.set(Calendar.SECOND, 0);
- case SECOND:
- calInstance.set(Calendar.MILLISECOND, 0);
- case MILLISECOND:
- // don't cut off anything
- break;
- default:
- throw new IllegalArgumentException("unknown resolution " + resolution);
- }
- return calInstance.getTimeInMillis();
- }
-
- /** Specifies the time granularity. */
- public static enum Resolution {
-
- YEAR(4), MONTH(6), DAY(8), HOUR(10), MINUTE(12), SECOND(14), MILLISECOND(17);
-
- final int formatLen;
- final SimpleDateFormat format;//should be cloned before use, since it's not threadsafe
-
- Resolution(int formatLen) {
- this.formatLen = formatLen;
- // formatLen 10's place: 11111111
- // formatLen 1's place: 12345678901234567
- this.format = new SimpleDateFormat("yyyyMMddHHmmssSSS".substring(0,formatLen),Locale.US);
- this.format.setTimeZone(GMT);
- }
-
- /** this method returns the name of the resolution
- * in lowercase (for backwards compatibility) */
- @Override
- public String toString() {
- return super.toString().toLowerCase(Locale.ENGLISH);
- }
-
- }
-
-}
fnp / pylucene.git / blobdiff