使用 restTemplate 下载内容类型八位字节流的文件

Question

在我的应用程序中，我收到来自 API 响应的文件，其Content-Type为application/octet-stream 。

我正在尝试将此文件作为ResponseEntity<Resource>返回到前端。

但我收到错误：

RestClientException: Could not extract response: no suitable HttpMessageConverter found for response type [class org.springframework.http.ResponseEntity] and content type [application/octet-stream]

通过浏览一些文档，我想到了使用与RestTemplate.getForEntity相同的responseEntityExtractor 。

我的代码：

RequestCallback requestCallback = request -> {
HttpHeaders headers1 = request
        .getHeaders();
headers1.set("Authorization", "Bearer " + template.getAccessToken());
headers1
        .setAccept(Arrays.asList(MediaType.APPLICATION_OCTET_STREAM, MediaType.ALL));
};

ResponseExtractor<ResponseEntity<Resource>> responseExtractor = template.responseEntityExtractor(ResponseEntity.class);
template.execute(url, HttpMethod.GET, requestCallback, responseExtractor, uriVariables);

可以理解的是，通过在请求回调中设置setAccept ，我们让restTemplate知道期望什么类型的内容，并且responseEntityExtractor()将返回ResponseExtractor<ResponseEntity<T>> 。

我错过了什么？

Answer 1

代替：

ResponseExtractor<ResponseEntity<Resource>> responseExtractor = template.responseEntityExtractor(ResponseEntity.class);

试试这个在 controller 方法中返回byte[] ：

ResponseExtractor<ResponseEntity<byte[]>> responseExtractor = template.responseEntityExtractor(byte[].class);
ResponseEntity<byte[]> results = template.responseEntityExtractor(byte[].class);
return results.getBody();

或返回ResponseEntity<Resource> ：

ResponseExtractor<ResponseEntity<byte[]>> responseExtractor = template.responseEntityExtractor(byte[].class);
ResponseEntity<byte[]> results = template.responseEntityExtractor(byte[].class);

ByteArrayResource byteArrayResource = new ByteArrayResource(results.getBody());
return new ResponseEntity<Resource>(byteArrayResource, null, HttpStatus.OK);