It appears that currently to register support for extra datatypes we must use the 'customDeserializers' and/or 'customSerializers' properties of the JsonItemReader / JsonItemWriter (see http://jberet.gitbooks.io/jberet-user-guide/content/jsonitemreader_and_jsonitemwriter/README.html ).

So to register a custom deserializer for Joda LocalDate (from https://github.com/FasterXML/jackson-datatype-joda) we need to add "com.fasterxml.jackson.datatype.joda.deser.LocalDateDeserializer" to the customDeserializers property.

But Jackson allows a simpler mechanism for registering datatypes:

objectMapper.registerModule(new JodaModule());

So I suggest that a new property "customDataTypeModules" is added where Jackson SimpleModule sub-classes can be listed, such as com.fasterxml.jackson.datatype.joda.JodaModule.