https://edgblog.wordpress.com/2014/02/17/jodatime-goodies-flexible-parsing/

JodaTime goodies – flexible parsing

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Parsing dates in Java with JodaTime is easy.

1. instantiate a date time formatter

1 2	DateTimeFormatter dateTimeFormatter = DateTimeFormat.forPattern("yyyyMMddHH:mm:ss.SSS") ;

2. …and parse the date time

1	dateTimeFormatter.parseDateTime("20120515 09:30:25.123") ;

3. but when  the date time format changes (say to include a timezone)…alarm bells.

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dateTimeFormatter.parseDateTime("20120515 09:30:25.123 +0000") ; //results in// java.lang.IllegalArgumentException: Invalid format: "20120515 09:30:25.123 +0000" is malformed at " +0000"

4. Fortunately the JodaTime api includes a DateTimeFormatterBuilder which can be used to build a dateTimeFormatter customised with multiple printers and parsers.

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DateTimeFormatter dateTimeFormatter= DateTimeFormat.forPattern("yyyyMMddHH:mm:ss.SSS") ;   DateTimeFormatter dateTimeFormatterWithTimeZone= DateTimeFormat.forPattern("yyyyMMdd HH:mm:ss.SSS Z");   DateTimeFormatter optionalTimeZoneFormatter= new DateTimeFormatterBuilder()  .append(null, //because no printing is required  new DateTimeParser[]{dateTimeFormatter.getParser(), dateTimeFormatterWithTimeZone.getParser()}).toFormatter();

5. now the same DateTimeFormatter handles different date time formats

1 2	optionalTimeZoneFormatter.parseDateTime("20120515 09:30:25.123") ; optionalTimeZoneFormatter.parseDateTime("20120515 09:30:25.123 +0000") ;