Java Parse Date parseDate(String str)

Description

Parse the given string as a date, using one of the accepted ISO-8601 date patterns.

License

Apache License

Exception

Parameter	Description
ParseException	If the given string is not a valid ISO-8601 date.

Declaration

public static Date parseDate(String str) throws ParseException 

Method Source Code

//package com.java2s;
/*//w ww.ja  v a  2 s  . com
 *      Copyright (C) 2012-2015 DataStax Inc.
 *
 *   Licensed 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 java.text.ParseException;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;

public class Main {
    /**
     * Valid ISO-8601 patterns for CQL timestamp literals.
     */
    private static final String[] iso8601Patterns = new String[] { "yyyy-MM-dd HH:mm", "yyyy-MM-dd HH:mm:ss",
            "yyyy-MM-dd HH:mmZ", "yyyy-MM-dd HH:mm:ssZ", "yyyy-MM-dd HH:mm:ss.SSS", "yyyy-MM-dd HH:mm:ss.SSSZ",
            "yyyy-MM-dd'T'HH:mm", "yyyy-MM-dd'T'HH:mmZ", "yyyy-MM-dd'T'HH:mm:ss", "yyyy-MM-dd'T'HH:mm:ssZ",
            "yyyy-MM-dd'T'HH:mm:ss.SSS", "yyyy-MM-dd'T'HH:mm:ss.SSSZ", "yyyy-MM-dd", "yyyy-MM-ddZ" };

    /**
     * Parse the given string as a date, using one of the accepted ISO-8601 date patterns.
     * <p/>
     * This method is adapted from Apache Commons {@code DateUtils.parseStrictly()} method (that is used Cassandra side
     * to parse date strings)..
     *
     * @throws ParseException If the given string is not a valid ISO-8601 date.
     * @see <a href="https://cassandra.apache.org/doc/cql3/CQL-2.2.html#usingtimestamps">'Working with timestamps' section of CQL specification</a>
     */
    public static Date parseDate(String str) throws ParseException {
        SimpleDateFormat parser = new SimpleDateFormat();
        parser.setLenient(false);
        // set a default timezone for patterns that do not provide one
        parser.setTimeZone(TimeZone.getTimeZone("UTC"));
        // Java 6 has very limited support for ISO-8601 time zone formats,
        // so we need to transform the string first
        // so that accepted patterns are correctly handled,
        // such as Z for UTC, or "+00:00" instead of "+0000".
        // Note: we cannot use the X letter in the pattern
        // because it has been introduced in Java 7.
        str = str.replaceAll("(\\+|\\-)(\\d\\d):(\\d\\d)$", "$1$2$3");
        str = str.replaceAll("Z$", "+0000");
        ParsePosition pos = new ParsePosition(0);
        for (String parsePattern : iso8601Patterns) {
            parser.applyPattern(parsePattern);
            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);
    }

    /**
     * Parse the given string as a date, using the supplied date pattern.
     * <p/>
     * This method is adapted from Apache Commons {@code DateUtils.parseStrictly()} method (that is used Cassandra side
     * to parse date strings)..
     *
     * @throws ParseException If the given string cannot be parsed with the given pattern.
     * @see <a href="https://cassandra.apache.org/doc/cql3/CQL-2.2.html#usingtimestamps">'Working with timestamps' section of CQL specification</a>
     */
    public static Date parseDate(String str, String pattern) throws ParseException {
        SimpleDateFormat parser = new SimpleDateFormat();
        parser.setLenient(false);
        // set a default timezone for patterns that do not provide one
        parser.setTimeZone(TimeZone.getTimeZone("UTC"));
        // Java 6 has very limited support for ISO-8601 time zone formats,
        // so we need to transform the string first
        // so that accepted patterns are correctly handled,
        // such as Z for UTC, or "+00:00" instead of "+0000".
        // Note: we cannot use the X letter in the pattern
        // because it has been introduced in Java 7.
        str = str.replaceAll("(\\+|\\-)(\\d\\d):(\\d\\d)$", "$1$2$3");
        str = str.replaceAll("Z$", "+0000");
        ParsePosition pos = new ParsePosition(0);
        parser.applyPattern(pattern);
        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);
    }
}

Related

1. parseDate(String source, String format)
2. parseDate(String src, String pattern)
3. parseDate(String srtDate, String pattern)
4. parseDate(String str)
5. parseDate(String str)
6. parseDate(String str)
7. parseDate(String str)
8. parseDate(String str)
9. parseDate(String str, boolean strict, String... parsePatterns)