Comments on: Optimistic Locking mit dem ETag Header

By: Jens

Jens — Fri, 20 Sep 2024 06:42:50 +0000

In reply to Jens. I have found some code about the initialization of the HandlerMethodReturnValueHandler. It uses a custom InitializingBean an the EtagHeaderResultReturnValueHandler wraps two HandlerMethodReturnValueHandler from the RequestMappingHandlerAdapter.


private HandlerMethodReturnValueHandler wrap(HandlerMethodReturnValueHandler handler) {
  if (handler instanceof RequestResponseBodyMethodProcessor
     || handler instanceof RepresentationModelProcessorHandlerMethodReturnValueHandler) {
    return new EtagHeaderResultReturnValueHandler(handler);
  }
  return handler; 
}

Hope this helps.

By: Jens

Jens — Thu, 19 Sep 2024 13:53:09 +0000

In reply to Lucca.

I am sorry but there is no puplic repository where you have access to the source code.
Registering the custom HandlerMethodReturnValueHandler was/is tricky.
As far as I remember, you have to use the RequestMappingHandlerAdapter and get the List of all HandlerMethodReturnValueHandler and inject the custom one at a appropiate place.
But I will look throw my private repositories for further information.

By: Lucca

Lucca — Thu, 19 Sep 2024 13:32:47 +0000

Is there a git repo where you can inspect the entire implementation. I am struggling to get the custom return value handler to work. I cant even get the handler to be registered and be called on a normal get request.

Greetings Lucca