Java - Convert OffsetDateTime/ timestamp to RegularTimePeriod to plot time series graph (Jfreechart)

问题

I currently trying to plot a graph using Jfreechart, and it accept only RegularTimePeriod

My date String is: zzz ***Wed Jan 15 10:00:03 +08 2020

From this Question I learned to parse such a string into an OffsetDateTime object. By calling OffsetDateTime I get this string:

2020-01-15T10:00:03+08:00

Then I was trying to make it into RegularTimePeriod, specifically "second". I'm lost and confused about the conversion.

Here is my code:

TimeSeries s1 = new TimeSeries("Something");

DateTimeFormatter f = DateTimeFormatter.ofPattern( "'zzz ***'EEE MMM dd HH:mm:ss x uuuu" ).withLocale( Locale.US );
OffsetDateTime moment = OffsetDateTime.parse( "zzz ***Wed Jan 15 10:00:03 +08 2020" , f );
Timestamp timestamp =Timestamp.valueOf(LocalDateTime.ofInstant(moment.toInstant(), ZoneOffset.UTC));

s1.add(timestamp,value);

error: Timestamp cannot be converted to RegularTimePeriod

Javadoc from JFree project:

• RegularTimePeriod
• TimeSeries

来源：https://stackoverflow.com/questions/59766445/java-convert-offsetdatetime-timestamp-to-regulartimeperiod-to-plot-time-serie