RestTemplate Spring Boot receive the file

Question

In my Spring Boot application I have implemented the RestController method that returns the file in response.getOutputStream() :

@RequestMapping(value = "/{fileId}", method = RequestMethod.GET)
@ResponseStatus(value = HttpStatus.OK)
public void getFile(@PathVariable @NotBlank String fileId, HttpServletResponse response) throws IOException, TelegramApiException {

    File file = fileService.getFile(fileId);
    InputStream inputStream = new BufferedInputStream(new FileInputStream(file));

    response.setContentType(FileUtils.detectMimeType(inputStream));

    response.setHeader(HttpHeaders.CONTENT_DISPOSITION, String.format("inline; filename=%s", file.getName()));
    response.setContentLength((int) file.length());

    FileCopyUtils.copy(inputStream, response.getOutputStream());
}

I would like to implement the integration test and use RestTemplate in order to invoke this endpoint and receive the file.

Something like:

restTemplate.getForObject(String.format("%s/v1.0/files/%s", getBaseApiUrl(), fileId), SOMECLASS.class);

Could you please show an example how it can be properly archived with Spring RestTemplate ?

Answer 1

I am assuming you want to start the server and call that API to see if it really works. Using spring-test, you can do this:

@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
public class HttpRequestTest {

    @LocalServerPort
    private int port;

    @Autowired
    private TestRestTemplate restTemplate;

    @Test
    public void greetingShouldReturnDefaultMessage() throws Exception {
    assertThat(this.restTemplate.getForObject("http://localhost:" + port + "/" + 1234, // File ID
            String.class)).contains("File Content Here");
   }
}

But you can actually test your logic only without start the server itself. Please refer to https://spring.io/guides/gs/testing-web/ for more info.

Answer 2

I have found the solution:

ResponseEntity<Resource> responseEntity = restTemplate.exchange(String.format("%s/v1.0/files/%s", getBaseApiUrl(), fileId), HttpMethod.GET, null, Resource.class);

return responseEntity.getBody().getInputStream();