Add version property to ResponseBody if the returned response is of collection type [DATAREST-636]

[spring-projects-issues]

Rakesh opened DATAREST-636 and commented

Currently, the version property is being stripped of from payload through PersistentEntityJackson2Module. The ETag support is available when individual entities are pulled. But, obviously it doesn't make sense for a collection (A collection of search results for example). Now, when the client intends to update an entity from a search result, it is counter productive to make a server call just to know the ETag of that entity.

In such a case, providing support for adding version number in the payload could be of some help.

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Reference URL: http://stackoverflow.com/questions/31843179/jackson-jpa-version-not-serialized/31855381

[spring-projects-issues]

Oliver Drotbohm commented

The HTTP specification for If-None-Match and If-Match states:

A client that has one or more entities previously obtained from the resource can verify that none of those entities is current by including a list of their associated entity tags in the If-None-Match header field.

As you can see this includes both "previously obtained" and "entity tags". Hence, to use this functionality an ETag has to be obtained. You can use a HEAD request
to obtain the ETag for an item resource to save bandwidth