Handling a body response as a file can be accomplished using BodyHandlers.ofFile(), as shown in the following snippet of code:

HttpResponse<Path> responseOfFile = client.send(
  request, HttpResponse.BodyHandlers.ofFile(
    Path.of("response.json")));

System.out.println("Status code: " + responseOfFile.statusCode());
System.out.println("Body: " + responseOfFile.body());

For specifying the open options, call ofFile(Path file, OpenOption... openOptions).