How to best get a byte array from a ClientResponse from Spring WebClient?

Question

I\'m trying out the new WebClient from Spring 5 (5.0.0.RC2) in a codebase that uses reactive programming and I\'ve had success mapping the JSON response from an

Answer 1

Oleg Estekhin's answer gives the OP what he asked for, but it's loading the entire response content in the memory, which is an issue for large responses. To get a chunk of bytes at a time instead, we can do the following:

client.get()
  .uri("uri")
  .exchange()
  .flatMapMany { it.body(BodyExtractors.toDataBuffers()) }

The size of these buffers would be 8192 kb by default; see this answer for changing that if needed.

Note that attempting to do dataBuffer.asByteBuffer().array() thrwos an exception if the ByteBuffer is not backed by an array.