ISO 8601 date parsing utility. : Date Parser « Data Type « Java





ISO 8601 date parsing utility.

     

/*
 * Copyright 1999,2004 The Apache Software Foundation.
 * 
 * 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.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;


/**
 * ISO 8601 date parsing utility.  Designed for parsing the ISO subset used in
 * Dublin Core, RSS 1.0, and Atom.
 * 
 * @author <a href="mailto:burton@apache.org">Kevin A. Burton (burtonator)</a>
 * @version $Id: ISO8601DateParser.java,v 1.2 2005/06/03 20:25:29 snoopdave Exp $
 */
public class ISO8601DateParser {

    // 2004-06-14T19:GMT20:30Z
    // 2004-06-20T06:GMT22:01Z

    // http://www.cl.cam.ac.uk/~mgk25/iso-time.html
    //    
    // http://www.intertwingly.net/wiki/pie/DateTime
    //
    // http://www.w3.org/TR/NOTE-datetime
    //
    // Different standards may need different levels of granularity in the date and
    // time, so this profile defines six levels. Standards that reference this
    // profile should specify one or more of these granularities. If a given
    // standard allows more than one granularity, it should specify the meaning of
    // the dates and times with reduced precision, for example, the result of
    // comparing two dates with different precisions.

    // The formats are as follows. Exactly the components shown here must be
    // present, with exactly this punctuation. Note that the "T" appears literally
    // in the string, to indicate the beginning of the time element, as specified in
    // ISO 8601.

    //    Year:
    //       YYYY (eg 1997)
    //    Year and month:
    //       YYYY-MM (eg 1997-07)
    //    Complete date:
    //       YYYY-MM-DD (eg 1997-07-16)
    //    Complete date plus hours and minutes:
    //       YYYY-MM-DDThh:mmTZD (eg 1997-07-16T19:20+01:00)
    //    Complete date plus hours, minutes and seconds:
    //       YYYY-MM-DDThh:mm:ssTZD (eg 1997-07-16T19:20:30+01:00)
    //    Complete date plus hours, minutes, seconds and a decimal fraction of a
    // second
    //       YYYY-MM-DDThh:mm:ss.sTZD (eg 1997-07-16T19:20:30.45+01:00)

    // where:

    //      YYYY = four-digit year
    //      MM   = two-digit month (01=January, etc.)
    //      DD   = two-digit day of month (01 through 31)
    //      hh   = two digits of hour (00 through 23) (am/pm NOT allowed)
    //      mm   = two digits of minute (00 through 59)
    //      ss   = two digits of second (00 through 59)
    //      s    = one or more digits representing a decimal fraction of a second
    //      TZD  = time zone designator (Z or +hh:mm or -hh:mm)
    public static Date parse( String input ) throws java.text.ParseException {

        //NOTE: SimpleDateFormat uses GMT[-+]hh:mm for the TZ which breaks
        //things a bit.  Before we go on we have to repair this.
        SimpleDateFormat df = new SimpleDateFormat( "yyyy-MM-dd'T'HH:mm:ssz" );
        
        //this is zero time so we need to add that TZ indicator for 
        if ( input.endsWith( "Z" ) ) {
            input = input.substring( 0, input.length() - 1) + "GMT-00:00";
        } else {
            int inset = 6;
        
            String s0 = input.substring( 0, input.length() - inset );
            String s1 = input.substring( input.length() - inset, input.length() );

            input = s0 + "GMT" + s1;
        }
        
        return df.parse( input );
        
    }

    public static String toString( Date date ) {
        
        SimpleDateFormat df = new SimpleDateFormat( "yyyy-MM-dd'T'HH:mm:ssz" );
        
        TimeZone tz = TimeZone.getTimeZone( "UTC" );
        
        df.setTimeZone( tz );

        String output = df.format( date );

        int inset0 = 9;
        int inset1 = 6;
        
        String s0 = output.substring( 0, output.length() - inset0 );
        String s1 = output.substring( output.length() - inset1, output.length() );

        String result = s0 + s1;

        result = result.replaceAll( "UTC", "+00:00" );
        
        return result;
        
    }

}

   
    
    
    
    
  










Related examples in the same category

1.Date parser for ISO 8601 format
2.Date Utils
3.Date To String
4.Perform date validations
5.Parses a string representing a date by trying a variety of different parsers.
6.Parses a time period into a long. Translates possible [msec|sec|min|h] suffixes
7.A method to get the current date as an array of components 0 = year, 1 = month, 2 = day
8.ISO 8601 date parsing utility. Designed for parsing the ISO subset used in Dublin Core, RSS 1.0, and Atom.
9.A simple XML parser that starts parsing right away and validates along the way.