Mega Code Archive
Parses a string representing a date by trying a variety of different parsers
<![CDATA[
import java.math.BigDecimal;
import java.math.BigInteger;
import java.text.ParseException;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
/**
* 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.
*/
/**
* <p>A suite of utilities surrounding the use of the
* {@link java.util.Calendar} and {@link java.util.Date} object.</p>
*
* <p>DateUtils contains a lot of common methods considering manipulations
* of Dates or Calendars. Some methods require some extra explanation.
* The truncate and round methods could be considered the Math.floor(),
* Math.ceil() or Math.round versions for dates
* This way date-fields will be ignored in bottom-up order.
* As a complement to these methods we've introduced some fragment-methods.
* With these methods the Date-fields will be ignored in top-down order.
* Since a date without a year is not a valid date, you have to decide in what
* kind of date-field you want your result, for instance milliseconds or days.
* </p>
*
*
*
* @author <a href="mailto:sergek@lokitech.com">Serge Knystautas</a>
* @author Stephen Colebourne
* @author Janek Bogucki
* @author <a href="mailto:ggregory@seagullsw.com">Gary Gregory</a>
* @author Phil Steitz
* @author Robert Scholte
* @since 2.0
* @version $Id: DateUtils.java 634096 2008-03-06 00:58:11Z niallp $
*/
public class Main {
//-----------------------------------------------------------------------
/**
* <p>Parses a string representing a date by trying a variety of different parsers.</p>
*
* <p>The parse will try each parse pattern in turn.
* A parse is only deemed sucessful if it parses the whole of the input string.
* If no parse patterns match, a ParseException is thrown.</p>
*
* @param str the date to parse, not null
* @param parsePatterns the date format patterns to use, see SimpleDateFormat, not null
* @return the parsed date
* @throws IllegalArgumentException if the date string or pattern array is null
* @throws ParseException if none of the date patterns were suitable
*/
public static Date parseDate(String str, String[] parsePatterns) throws ParseException {
if (str == null || parsePatterns == null) {
throw new IllegalArgumentException("Date and Patterns must not be null");
}
SimpleDateFormat parser = null;
ParsePosition pos = new ParsePosition(0);
for (int i = 0; i < parsePatterns.length; i++) {
if (i == 0) {
parser = new SimpleDateFormat(parsePatterns[0]);
} else {
parser.applyPattern(parsePatterns[i]);
}
pos.setIndex(0);
Date date = parser.parse(str, pos);
if (date != null && pos.getIndex() == str.length()) {
return date;
}
}
throw new ParseException("Unable to parse the date: " + str, -1);
}
}
]]>