Using LATEST java SAP Cloud Sdk
We are trying to perform an update to OutboundDelivery in S/4 system. We are using API_OUTBOUND_DELIVERY_SRV version 2 for it. The service requires us to use etag, i.e. it requires us to provide a header - if-match with the corresponding value of the etag.
We are using VDM for performing the update and are making use of com.sap.cloud.sdk.s4hana.datamodel.odata.namespaces.outbounddeliveryv2.batch.OutboundDeliveryV2ServiceBatch. Please find the code snippet used for update, below:
...
OutboundDeliveryV2ServiceBatch service = // Instantiate service;
List<OutbDeliverItem> itemsToUpdate = new ArrayList<>();
items.add(OutbDeliveryItem.builder()
.deliveryDocument("some key")
.deliveryDocumentItem("some key")
.build());
// Assume more additions to items
...
...
...
OutboundDeliveryV2ServiceBatchChangeSet changeSet = service.beginChangeSet();
items.forEach(changeSet::updateOutbDeliveryItem);
changeSet.endChangeSet();
BatchResponse response = service.execute(someDestination);
...
As soon as service.execute(someDestination) is executed, the update is not performed on S/4 and the logs on S/4 give following error:
The Data Service Request is required to be conditional. Try using the "If-Match" header.
My questions:
Please note that we have to use the batch operation itself due to performance reasons.
The ETags are missing because the items to be updated are programmatically created in your application using the builder pattern. Therefore, no ETags are present on them when you execute update and the SDK has none available to set the "If-Match" header when building up the request.
The solution is to fetch the items from the server first. This also ensures that you have the latest version of them for the update which is a prerequisite for updating them.
Thank you for your answer @MatKuhr. Actually we have to update a lot of items (in range of about ~1000 items). It is not efficient for us to read so much items first due to performance reasons. Also the java SDK doesn't provide batch read functionality via VDM as of now (correct me if I am wrong). In addition to this, does the SDK always require me to read an item first and then update it? Isn't it possible to simply update an item with a given key?
You can fetch all items by using the
getAllOutbDeliveryItem()method exposed by the service. This will fetch all of the items with the correct etags. There is no way around fetching first because you need to fetch the latest ETag in order to perform update or delete operations.Thank you very much. Combining
getAllOutbDeliveryItem()withfilter()on a specific property, I am able to limit the response and get eTags too. Thank you!Great! Could you please mark the answer as accepted so that others can see it easier?