Expose GridFSFile through [Reactive]GridFsResource [DATAMONGO-2240]

[spring-projects-issues]

Juergen Zimmermann opened DATAMONGO-2240 and commented

ReactiveGridFsResource has no method to retrieve the value of _contentType or at least metadata. For example in a REST application the response header of a GET request cannot be set to the correct content type.

My ugly workaround is a Kotlin extension function:

import com.mongodb.client.gridfs.model.GridFSFile
import org.springframework.data.mongodb.gridfs.ReactiveGridFsResource
import org.springframework.util.ReflectionUtils.findField
import org.springframework.util.ReflectionUtils.getField
import org.springframework.util.ReflectionUtils.makeAccessible

fun ReactiveGridFsResource.contentType(): String {
  val fileProp = findField(ReactiveGridFsResource::class.java, "file")!!
  makeAccessible(fileProp)
  val file = getField(fileProp, this) as GridFSFile
  return file.metadata?.get("_contentType") as String
}

---

Affects: 2.2 M2 (Moore)

Referenced from: pull request #741

[spring-projects-issues]

Mark Paluch commented

This is by design. Please note that GridFsResource.getContentType() is deprecated and therefore we didn't carry over the method to the newly introduced ReactiveGridFsResource.

A ReactiveGridFsResource gets created through ReactiveGridFsTemplate.getResource(GridFSFile). Care to elaborate why you don't use GridFSFile directly?

[spring-projects-issues]

Juergen Zimmermann commented

Mark Paluch I'm using public Mono<ReactiveGridFsResource> getResource(String location) from ReactiveGridFsTemplate. Therefore, I have ReactiveGridFsResource directly

[spring-projects-issues]

Juergen Zimmermann commented

IMO having ReactiveGridFsResource.getFile() would be sufficient

[spring-projects-issues]

Mark Paluch commented

Exposing GridFSFile seems reasonable. In some cases, that one can be null, but we can cover that API-wise

[spring-projects-issues]

Juergen Zimmermann commented

Mark Paluch Do see a chance that this will be available in M3?