Uploading multipart form-data linux file using Rest template : I/O error on POST request for Illegal unquoted character ((CTRL-CHAR, code 13))

Question

I'm having issues uploading a file via resttemplate client on linux

Here's what I have currently

    HttpHeaders headers = new HttpHeaders();
    headers.setContentType(MediaType.MULTIPART_FORM_DATA);
    MultiValueMap<String, Object> form = new LinkedMultiValueMap<>();
    form.add("image", new FileSystemResource(imageFile));
    HttpEntity<MultiValueMap<String, Object>> httpEntity = new HttpEntity<>(form, headers);
    UploadResponse response = restTemplate.postForEntity(uploadUrl,httpEntity, UploadResponse.class).getBody();

Code works fine on windows but returns this error on linux:

 I/O error on POST request for "https://baseurl/api/v1/upload": Illegal unquoted character ((CTRL-CHAR, code 13)): has to be escaped using backslash to be included in string value
 at [Source: (StringReader); line: 1, column: 47]; nested exception is com.fasterxml.jackson.core.JsonParseException: Illegal unquoted character ((CTRL-CHAR, code 13)): has to be escaped using backslash to be included in string value

Anyone has an idea what might be wrong?

Try to just print new FileSystemResource(imageFile) and see if it picks up the image file correctly on linux or not. — JCompetence, Nov 03 '21 at 10:49
Curious, could you try to setContentType("multipart/form-data;charset=UTF-8"); instead. Lets see how it reacts. — JCompetence, Nov 03 '21 at 11:14

JCompetence · Answer 1 · 2021-11-03T11:30:19.753

0

The solution to this seems to be to update your ObjectMapper to ignore CTRL characters, which Linux might be inferring

@Autowired
private ObjectMapper objectMapper;

@Autowired
private RestTemplate restTemplate;

private void patchRestTemplate() {

    objectMapper.configure(MapperFeature.ACCEPT_CASE_INSENSITIVE_PROPERTIES, true);

    restTemplate.getMessageConverters().forEach(httpMessageConverter -> {

        if (httpMessageConverter instanceof MappingJackson2HttpMessageConverter) {

            ((MappingJackson2HttpMessageConverter) httpMessageConverter).setObjectMapper(objectMapper);
        }
    });
}

Reference: JsonParseException : Illegal unquoted character ((CTRL-CHAR, code 10)

edited Nov 03 '21 at 11:30

answered Nov 03 '21 at 11:24

JCompetence

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Didn't work for me, got the same error – Adefisola Adigun Nov 03 '21 at 14:02
Are you actually patching the restTemplate before doing restTemplate.postForEntity?? – JCompetence Nov 03 '21 at 14:08
I've just figured out the issue. Thanks very much. Your solution helped put me on the right path. an existing internal restTemplate client interceptor logger library I was using did not cater for logging "multipart/form-data" requests. – Adefisola Adigun Nov 03 '21 at 14:14

Uploading multipart form-data linux file using Rest template : I/O error on POST request for Illegal unquoted character ((CTRL-CHAR, code 13))

1 Answers1