[
https://issues.apache.org/jira/browse/OLINGO-15?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13764266#comment-13764266
]
Michael Bolz commented on OLINGO-15:
------------------------------------
With the last commits (see list below) I refactored the *content negotiation*
and handling/setting of the {{Content-Type}} header information.
Now it is intently in the {{ContentNegotiator}} which therefore got more *OData
specific logic* in the form of {{UriInfo}} and {{ODataRequest}}.
Each {{EntityProvider}} now only provides the {{Entity}} without setting of the
{{Content-Type}}.
The {{ODataProcessor}} implementation can set the {{ContentType}} in the
{{ODataResponse}} if wished. If it is not set the {{ContentNegotiator}} will
set it (on behalf of the {{ODataRequestHandler}}.
IMHO this is a far better solution as before and hence this issue is fixed (for
me) and can be closed.
* {{99e549d}} Moved complete content type handling into ContentNegotiator
* {{31c3d8f}} Refactored content negotiation from RequestHandler into
ContentNegotiator
* {{060f9c6}} Refactoring for OLINGO-15 (ATOM/XML-Part)
* {{ce78a0b}} Refactoring for OLINGO-15 (JSON-Part)
> Content Type of response hard coded in EntityProvider
> -----------------------------------------------------
>
> Key: OLINGO-15
> URL: https://issues.apache.org/jira/browse/OLINGO-15
> Project: Olingo
> Issue Type: Improvement
> Components: odata2-core
> Affects Versions: 0.0.0, 1.0.0
> Reporter: Michael Bolz
> Fix For: 1.0.0
>
>
> Content Type Negotiation is done correctly (in most cases) but in the end the
> content type which is set is hard coded in the response (see example for JSON
> below).
> After a review of the {{AcceptHeader}} content type process flow through the
> {{Dispatcher}}, the {{RequestHandler}}, the {{Processor Implementation}}, the
> {{EntityProvider}} and back it would be better to refactor the behavior were
> the {{Content-Type Header}} of the response is set.
> Suggested is to do the content negotiation at the {{RequestHandler}}, give
> the result to the {{Dispatcher}} which simply pass through it to the
> {{Processor}} implementation. The {{EntityProvider}} based classes *MUST NOT*
> set the {{Content-Type Header}} of the {{ODataResponse}}. The only exception
> is when the resulting {{Content-Type}} can only have one valid value, which
> is e.g. the case for a {{$count}} request which only can be {{Content-Type:
> text/plain}}.
> The {{Processor}} implementation returns with the {{ODataResponse}} back to
> the {{RequestHandler}} which then checks if the {{Content-Type Header}} is
> set and *only if it is not set* the {{RequestHandler}} set the header with
> the resulted content type from the before done content negotiation. If the
> header is already set (from the {{Processor}}) it is not changed.
> With this solution the {{Content-Type}} handling and set for the response is
> not spreaded through several layers of the library. It then is clear that it
> is done by the {{RequestHandler}} and can be overwritten by the implementing
> {{Processor}}.
> In addition the {{EntityProvider}} does not have the {{Content-Type}} hard
> coded which allows a better pre defined content negotiation in the library
> (especially with parameters in the {{AcceptHeader}}).
> Appendix:
> JsonEntityProvider:
> {code}
> @Override
> public ODataResponse writeFeed(final EdmEntitySet entitySet, final
> List<Map<String, Object>> data, final EntityProviderWriteProperties
> properties) throws EntityProviderException {
> final EntityInfoAggregator entityInfo =
> EntityInfoAggregator.create(entitySet, properties.getExpandSelectTree());
> CircleStreamBuffer buffer = new CircleStreamBuffer();
> try {
> BufferedWriter writer = new BufferedWriter(new
> OutputStreamWriter(buffer.getOutputStream(), DEFAULT_CHARSET));
> new JsonFeedEntityProducer(properties).append(writer, entityInfo, data,
> true);
> writer.flush();
> buffer.closeWrite();
> ----> return
> ODataResponse.entity(buffer.getInputStream()).contentHeader(HttpContentType.APPLICATION_JSON).build();
> } catch (EntityProviderException e) {
> buffer.close();
> throw e;
> } catch (Exception e) {
> buffer.close();
> throw new
> EntityProviderException(EntityProviderException.EXCEPTION_OCCURRED.addContent(e.getClass().getSimpleName()),
> e);
> }
> }
> {code}
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira
