如何在spring mvc rest controller中返回二进制数据而不是base64编码的byte []

我想通过spring-mvc-rest控制器返回生成的pdf文件.这是我目前正在使用的代码的缩短版本:

@RestController
@RequestMapping("/x")
public class XController {
    @RequestMapping(value = "/", method = RequestMethod.GET)
    public ResponseEntity find() throws IOException {
        byte[] pdf = createPdf();

        HttpHeaders headers = new HttpHeaders();
        headers.setContentType(new MediaType("application", "pdf"));
        headers.setContentDispositionFormData("attachment", "x.pdf");
        headers.setContentLength(pdf.length);
        return new ResponseEntity(pdf, headers, HttpStatus.OK);
    }
}

这工作得很好,它只是返回实际的字节数组作为base64编码:(

curl -i 'http://127.0.0.1:8080/app/x'

Server: Apache-Coyote/1.1
Content-Disposition: form-data; name="attachment"; filename=x.pdf"
Content-Type: application/pdf
Content-Length: 138654
Date: Fri, 08 Jan 2016 11:25:38 GMT

"JVBERi0xLjYNJeLjz9MNCjMyNCAwIG9iag [...]

(顺便说一下,响应甚至不包含结束":)

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