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.apache.solr.handler.extraction; import java.text.ParseException; import java.text.SimpleDateFormat; import java.time.Instant; import java.time.format.DateTimeFormatter; import java.time.format.DateTimeFormatterBuilder; import java.util.ArrayList; import java.util.Arrays; import java.util.Calendar; import java.util.Collection; import java.util.Date; import java.util.Iterator; import java.util.Locale; import java.util.TimeZone; /** * This class has some code from HttpClient DateUtil. */ public class ExtractionDateUtil { //start HttpClient /** * Date format pattern used to parse HTTP date headers in RFC 1123 format. */ public static final String PATTERN_RFC1123 = "EEE, dd MMM yyyy HH:mm:ss zzz"; /** * Date format pattern used to parse HTTP date headers in RFC 1036 format. */ public static final String PATTERN_RFC1036 = "EEEE, dd-MMM-yy HH:mm:ss zzz"; /** * Date format pattern used to parse HTTP date headers in ANSI C * <code>asctime()</code> format. */ public static final String PATTERN_ASCTIME = "EEE MMM d HH:mm:ss yyyy"; //These are included for back compat private static final Collection<String> DEFAULT_HTTP_CLIENT_PATTERNS = Arrays.asList(PATTERN_ASCTIME, PATTERN_RFC1036, PATTERN_RFC1123); private static final Date DEFAULT_TWO_DIGIT_YEAR_START; static { Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("GMT"), Locale.ROOT); calendar.set(2000, Calendar.JANUARY, 1, 0, 0); DEFAULT_TWO_DIGIT_YEAR_START = calendar.getTime(); } private static final TimeZone GMT = TimeZone.getTimeZone("GMT"); //end HttpClient //--------------------------------------------------------------------------------------- /** * Differs by {@link DateTimeFormatter#ISO_INSTANT} in that it's lenient. */ public static final DateTimeFormatter ISO_8601_PARSER = new DateTimeFormatterBuilder().parseCaseInsensitive() .parseLenient().appendInstant().toFormatter(Locale.ROOT); /** * A suite of default date formats that can be parsed, and thus transformed to the Solr specific format */ public static final Collection<String> DEFAULT_DATE_FORMATS = new ArrayList<>(); static { DEFAULT_DATE_FORMATS.add("yyyy-MM-dd'T'HH:mm:ss'Z'"); DEFAULT_DATE_FORMATS.add("yyyy-MM-dd'T'HH:mm:ss"); DEFAULT_DATE_FORMATS.add("yyyy-MM-dd"); DEFAULT_DATE_FORMATS.add("yyyy-MM-dd hh:mm:ss"); DEFAULT_DATE_FORMATS.add("yyyy-MM-dd HH:mm:ss"); DEFAULT_DATE_FORMATS.add("EEE MMM d hh:mm:ss z yyyy"); DEFAULT_DATE_FORMATS.addAll(DEFAULT_HTTP_CLIENT_PATTERNS); } /** * Returns a formatter that can be use by the current thread if needed to * convert Date objects to the Internal representation. * * @param d The input date to parse * @return The parsed {@link java.util.Date} * @throws java.text.ParseException If the input can't be parsed */ public static Date parseDate(String d) throws ParseException { return parseDate(d, DEFAULT_DATE_FORMATS); } public static Date parseDate(String d, Collection<String> fmts) throws ParseException { if (d.length() > 0 && d.charAt(d.length() - 1) == 'Z') { try { return new Date(ISO_8601_PARSER.parse(d, Instant::from).toEpochMilli()); } catch (Exception e) { //ignore; perhaps we can parse with one of the formats below... } } return parseDate(d, fmts, null); } /** * Slightly modified from org.apache.commons.httpclient.util.DateUtil.parseDate * <p> * Parses the date value using the given date formats. * * @param dateValue the date value to parse * @param dateFormats the date formats to use * @param startDate During parsing, two digit years will be placed in the range * <code>startDate</code> to <code>startDate + 100 years</code>. This value may * be <code>null</code>. When <code>null</code> is given as a parameter, year * <code>2000</code> will be used. * @return the parsed date * @throws ParseException if none of the dataFormats could parse the dateValue */ public static Date parseDate(String dateValue, Collection<String> dateFormats, Date startDate) throws ParseException { if (dateValue == null) { throw new IllegalArgumentException("dateValue is null"); } if (dateFormats == null) { dateFormats = DEFAULT_HTTP_CLIENT_PATTERNS; } if (startDate == null) { startDate = DEFAULT_TWO_DIGIT_YEAR_START; } // trim single quotes around date if present // see issue #5279 if (dateValue.length() > 1 && dateValue.startsWith("'") && dateValue.endsWith("'")) { dateValue = dateValue.substring(1, dateValue.length() - 1); } //TODO upgrade to Java 8 DateTimeFormatter. But how to deal with the GMT as a default? SimpleDateFormat dateParser = null; Iterator formatIter = dateFormats.iterator(); while (formatIter.hasNext()) { String format = (String) formatIter.next(); if (dateParser == null) { dateParser = new SimpleDateFormat(format, Locale.ENGLISH); dateParser.setTimeZone(GMT); dateParser.set2DigitYearStart(startDate); } else { dateParser.applyPattern(format); } try { return dateParser.parse(dateValue); } catch (ParseException pe) { // ignore this exception, we will try the next format } } // we were unable to parse the date throw new ParseException("Unable to parse the date " + dateValue, 0); } }