Support for union types about jsonschema2pojo HOT 2 CLOSED

From [email protected] on May 07, 2012 22:19:27
The only time I have used union types is to allow null for a field. Note that the schema calls out this use case specifically in section 5.1 :
" null Value MUST be null. Note this is mainly for purpose of
being able use union types to define nullability. If this type
is not included in a union, null values are not allowed (the
primitives listed above do not allow nulls on their own)."

A lot of the types for my fields look like: {"type": ["string","null"]}
I only speak from my experience so I don't know how commonly used this is but it should be simple to add a special case for it. It would work seamlessly as long as boxed types are being used.

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From [email protected] on May 08, 2012 21:55:44
This issue has been around for a while and I'm now leaning away from the 3rd option described above. It would be nice to have a simple implementation for now that doesn't impose any additional requirements on the json (like extra 'type' properties).

I've fixed this as per Option 1: if an array is encountered (a union type) just use the first type in the array. Maybe a more sophisticated handling of union types could be applied to a later version, but in general if you want to do data-binding to a statically typed language like Java it's best to avoid such constructs.

This should satisfy your use-case Patrick, just make sure the "null" type comes last.

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