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，我从 API 响应中接收到一个文件，其 Content-Type 是 application/octet-stream。

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

但我遇到了错误：

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 responseEntityExtractor，这与 RestTemplate.getForEntity 中的相同。

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 知道预期的内容类型，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);

试试这个在控制器方法中返回byte[]：

ResponseExtractor<ResponseEntity<byte[]>> responseExtractor = template.responseEntityExtractor(byte[].class);
ResponseEntity<byte[]> results = template.execute(url, HttpMethod.GET, requestCallback, responseExtractor, uriVariables);
return results.getBody();

或者这个返回ResponseEntity<Resource>:

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

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