CODEWITHSUNDEEP
javaspringhttpservlets
alex.p
alex.p

Reputation: 2739

Implementing If-Match HTTP Header in Spring

The ShallowEtagHeaderFilter which is part of Spring processes the If-None-Match header on an Http request. As part of the Http 1.1 spec this returns an Http status of 304 - Not Modified if the contents of the If-None-Match header sent on the request is the same as the Etag header. This is helpful for caching as it means that if the Etag is the same on the client and server then the contents will be identical.

This is fine.

However my question is this - does Spring have support for the If-Match header (again part of HTTP 1.1) rather than If-None-Match because as far as the docs go it looks like the ShallowEtagHeaderFilter only processes the If-None-Match header. I need the If-Match header to prevent simultaneous requests from overwriting the previous one. IE I only want the request to be processed if the Etags are the same and hence they have the latest version of the entity.

Upvotes: 3

Views: 3038

Answers (1)

Eugen
Eugen

Reputation: 8783

It doesn't look like the ShallowEtagHeaderFilter supports If-Match: 

curl "Accept: application/json" -H 'If-Match: "somevalue"' -i http://localhost:8080/rest-sec/api/resources/1

HTTP/1.1 200 OK
Server: Apache-Coyote/1.1
ETag: "03cb37ca667706c68c0aad4cb04c3a211"
Content-Type: application/json;charset=UTF-8
Content-Length: 56
Date: Fri, 11 Jan 2013 14:58:40 GMT

I opened a JIRA issue to track this: https://jira.springsource.org/browse/SPR-10164

Upvotes: 1

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