Updates with If-Unmodified-Since header return 412 but update the entity [DATAREST-1234]

Stefan Fussenegger opened DATAREST-1234 and commented

Currently a request containing If-Unmodified-Since returns 412 Precondition Failed but the object state is updated. This can be verified by appending this code to example.springdata.rest.headers.WebIntegrationTests in spring-data-examples/rest/headers:

mvc.perform(get(uri).header(IF_NONE_MATCH, response.getHeader(ETAG))).//
    andExpect(status().isNotModified());

Thread.sleep(1000L);
mvc.perform(patch(uri).header(IF_UNMODIFIED_SINCE, response.getHeader(LAST_MODIFIED)).accept(MediaType.APPLICATION_JSON).contentType(MediaType.APPLICATION_JSON_UTF8).content("{\"firstname\": \"changed\"}")).//
                andExpect(status().isPreconditionFailed());

mvc.perform(get(uri).header(IF_NONE_MATCH, response.getHeader(ETAG))).//
    andExpect(status().isNotModified()); // fails with 200 OK

The reason this happens is that SDR ignores the header completely, updates the state accordingly and returns with 200 OK. Later a 412 Precondition Failed is generated by org.springframework.web.context.request.ServletWebRequest.checkNotModified(String, long) as the returned Last-Modified generated by the updated object is compared with If-Unmodified-Since.

Note that this behavior can only be observed for 200 OK response, i.e. if the response contains the body - which it does by default if an Accept header has been sent (see returnStatus == 200 in org.springframework.web.servlet.mvc.method.annotation.HttpEntityMethodProcessor.handleReturnValue(Object, MethodParameter, ModelAndViewContainer, NativeWebRequest))

1 votes, 2 watchers