Spring WebClient: How to stream large byte[] to file?

Question

It seems like it the Spring RestTemplate isn\'t able to stream a response directly to file without buffering it all in memory. What is the proper to achieve this us

Answer 1

I'm not sure if you have access to RestTemplate in your current usage of spring, but this one have worked for me.

RestTemplate restTemplate // = ...;

RequestCallback requestCallback = request -> request.getHeaders()
        .setAccept(Arrays.asList(MediaType.APPLICATION_OCTET_STREAM, MediaType.ALL));

// Streams the response
ResponseExtractor responseExtractor = response -> {
    // Here I write the response to a file but do what you like
    Path path = Paths.get("http://some/path");
    Files.copy(response.getBody(), path);
    return null;
};
restTemplate.execute(URI.create("www.something.com"), HttpMethod.GET, requestCallback, responseExtractor);