如何使用 spring webflux 上传和读取文本文件？

Question

I need to upload a file and read the content, with spring mvc that is easy, but with spring webflux I have no idea how to deal with a FilePart and a Flux of DataBuffer

I'm expecting something like this return:

    @PostMapping("/upload")
    fun readFile(@RequestPart("file", required = true) file: Mono<FilePart>): Mono<ResponseEntity<String>> {
        return Mono.just("my text content")
                .map {
                    ResponseEntity.ok()
                            .body(it)
                }
    }

Answer 1

I made it work using the following code:

    @PostMapping("/upload")
fun readFile(@RequestPart("file", required = true) file: Mono<FilePart>): Mono<ResponseEntity<String>> {

    return file.flatMap {
        it.content().map { dataBuffer ->
            IOUtils.inputStreamAsString(dataBuffer.asInputStream(), "UTF-8")
        }.toMono()
    }.map {
        ResponseEntity.ok()
                .body(it)
    }
}