Spring WebFlux：使用 headers 为 Mixed-Replace HTTP 响应流式传输原始 HTTP 响应字符串

Question

使用 Spring WebFlux 我想 return Mixed-Replace 看起来像这样的 HTTP 响应：

HTTP/1.1 200 Ok
Content-Type: multipart/x-mixed-replace; boundary=--icecream

--icecream
Content-Type: image/jpeg
Content-Length: [length]

[data]

--icecream
Content-Type: image/jpeg
Content-Length: [length]

[data]

数据从 Flux 流式传输（想想 Flux.interval(1000).map(fetchImageFrame)），但我找不到如何流式传输原始 HTTP 响应数据的方法，大多数示例都让我可以访问 HTTP body只有，但不是我可以控制 HTTP 的整个响应 headers.

Answer 1

您是否尝试过将 Flux 响应包装在 ResponseEntity 中并在 ResponseEntity 上设置所需的 headers？

类似于：

@GetMapping(value = "/stream")
ResponseEntity<Flux<byte[]>> streamObjects() {
    Flux<byte[]> flux = Flux.fromStream(fetchImageFrame()).delayElements(Duration.ofSeconds(5));
    HttpHeaders headers = HttpHeaders.writableHttpHeaders(HttpHeaders.EMPTY);
    headers.add("Content-Type", "multipart/x-mixed-replace; boundary=--icecream");
    return new ResponseEntity<>(flux, headers, HttpStatus.OK);
}

private Stream<byte[]> fetchImageFrame() {
    return List.of(
            load("image1.jpg"),
            load("image2.jpg"),
            load("image3.jpg"),
            load("image4.jpg")
    ).stream();
}

private byte[] load(String name) {
    try {
        byte[] raw = Files.readAllBytes(Paths.get(name));
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        String headers =
                "--icecream\r\n" +
                "Content-Type: image/jpeg\r\n" +
                "Content-Length: " + raw.length + "\r\n\r\n";
        bos.write(headers.getBytes());
        bos.write(raw);
        return bos.toByteArray();
    } catch (IOException e) {
        throw new RuntimeException(e);
    }
}

Spring WebFlux：使用 headers 为 Mixed-Replace HTTP 响应流式传输原始 HTTP 响应字符串

Spring WebFlux: Stream raw HTTP response string with headers for Mixed-Replace HTTP Response

spring-webflux