Apache Http 4.5 StringBody Constructor Not Exporting Content Type in Request

Question

Using Apache Http 4.5 MultipartEntityBuilder and can't seem to figure out why the StringBody(String, ContentType) constructor doesn't actually output the Content-Type in the request form body.

public HttpRequestBase build() throws UnsupportedEncodingException {
    HttpPost httpPost = new HttpPost("https://{server}/restapi/{apiVersion}/accounts/{accountId}/envelopes");

    MultipartEntityBuilder builder = MultipartEntityBuilder.create();
    builder.setContentType(ContentType.MULTIPART_FORM_DATA);
    builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);
    builder.setBoundary("AAA");

    //add form body
    builder.addPart(generateJsonFormBodyPart());

    //add file body
    builder.addPart(generateFileFormBodyPart()); //<--intentionally omitted

    HttpEntity multipart = builder.build();

    httpPost.setEntity(multipart);

    return httpPost;

}

private FormBodyPart generateJsonFormBodyPart() throws UnsupportedEncodingException{
        StringBody json = new StringBody(packageJson(), ContentType.APPLICATION_JSON); //<--THIS DOESN'T SEEM TO WORK    
        StringBuilder buffer = new StringBuilder();
        buffer.append("form-data");

        String contentDisposition = buffer.toString();

        FormBodyPartBuilder partBuilder = FormBodyPartBuilder.create("application/json", json);
        partBuilder.setField(MIME.CONTENT_DISPOSITION, contentDisposition);

        FormBodyPart fbp = partBuilder.build();

        return fbp;
    }

The file portion outputs ok but I get a "Bad Request" return from the peer which I assume is because it has very specific request parameters.

Required Request Output

Accept: application/json Content-Type: multipart/form-data; boundary=AAA

--AAA Content-Type: application/json Content-Disposition: form-data

json removed

--AAA Content-Type: application/pdf Content-Disposition: file; filename="test1.pdf";documentid=1

document removed

Actual Apache Http 4.5 Output

X-Docusign-Act-As-User: [email protected] Accept-Encoding: gzip,deflate User-Agent: Apache-HttpClient/4.5 (Java/1.8.0_65) Connect-Time: 0 Host: requestb.in Connection: close Content-Length: 3178 Authorization: bearer xxxxrandomoauthtokenxxxxx Content-Type: multipart/form-data; boundary=AAA; charset=ISO-8859-1 Via: 1.1 vegur X-Request-Id: 89cd1cf5-3615-41e8-84ba-cd076a03af67 Total-Route-Time: 0

--AAA Content-Disposition: form-data //<--the problem. should be application/json no?

{"status":"created","emailBlurb":"Welcome to Confluence","emailSubject":"Welcome to Confluence","documents":{"name":"Welcome to Confluence.html","documentId":"1","order":"1"},"recipients":{}}

--AAA Content-Disposition: file; filename="Welcome.html";documentid=1 Content-Type: text/html; charset=ISO-8859-1

h t m l string removed

Q: So why does the ContentType in the StringBody constructor get ignored? Is there a workaround or am I doing it wrong?

Kling Kling · Accepted Answer · 2016-03-04T12:40:22

I'm convinced this is a bug in Apache Http Mime for the FormBodyPart.build() when processing a StringBody. Evidence from release notes of 4.5.2 indicating bug fixes for other "body" types not outputting "Content-Type" supports this. I will be logging a defect.

The Workaround:

private FormBodyPart generateJsonFormBodyPart() throws UnsupportedEncodingException{
    StringBody json = new StringBody(getMyJsonStuff(), ContentType.APPLICATION_JSON); //<--THE GOGGLES, THEY DO NOTHING!!

    StringBuilder buffer = new StringBuilder();
    buffer.append("form-data");
    buffer.append("\r\n");
    buffer.append("Content-Type: application/json"); //<--tack this on to the 

    String kludgeForDispositionAndContentType = buffer.toString();

    FormBodyPartBuilder partBuilder = FormBodyPartBuilder.create("stuff", json);
    partBuilder.setField(MIME.CONTENT_DISPOSITION, kludgeForDispositionAndContentType);

    FormBodyPart fbp = partBuilder.build();

    return fbp;
}

Works like a charm.

Apache Http 4.5 StringBody Constructor Not Exporting Content Type in Request

1 Answers