How to deserialize ISO8601 duration string to Duration and Period objects with Jackson

Question

I have a string value containing ISO8601 duration string (P3Y6M4DT12H30M5S). How to deserialize it to Duration and Period object using Jackson ? I know that Duration accepts days, hours, minutes, seconds and Period years and months.

Answer 1

tl;dr

org.threeten.extra.PeriodDuration.parse( "P3Y6M4DT12H30M5S" ) ;

Details

• A Period represents a span of time on the scale of years, months, days.
• A Duration represents a span of time on the scale of hours, minutes, seconds, and nanoseconds.

A note of caution: Combining those two concepts into one, as seen in your example input string, rarely makes sense in practice.

PeriodDuration class

However, if you insist on using such values, there is a class for that. Add the ThreeTen-Extra library to your project. You can then access the PeriodDuration class.

No need to define a formatting pattern. Your input complies with the ISO 8601 standard. The java.time classes use the standard formats by default when parsing/generating text.

org.threeten.extra.PeriodDuration pd = PeriodDuration.parse( "P3Y6M4DT12H30M5S" ) ;

Generate text in standard ISO 8601 format.

String output = pd.toString() ;

You’ll find several handy methods on that class for construction, normalizing, math (addition, subtraction, negation), and more.

As for Jackson, I’m not a user. I don’t know how to use a third-party class as an automatic formatter in Jackson.

Answer 2

I didnt want use external dependency to use such simple approach so I implemented it by myself.

I created PeriodDuration class which contain Period and Duration fields.

Next I created deserializer which extends StdDeserializer and annotated PeriodDuration class with @JsonDeserializer(using = "nameOfMyCustomDeserializer.class). That deserializer split iso8601 duration string into two string, before 'T' and after 'T'. If period part is empty then set Period.ZERO but if duration partis empty then set Duration.ZERO.

Answer 3

Add com.fasterxml.jackson.datatype.jsr310.JavaTimeModule to your JsonMapper/ObjectMapper - see https://github.com/FasterXML/jackson-modules-java8.

For serialization, you will need to disable SerializationFeature.WRITE_DATES_AS_TIMESTAMPS - this is enabled, by default. When disabled the duration is output is ISO-8601 format (eg PT12H for 12 hours).