Getting this code to run in Java was harder than I thought. I got it up and running in Postman with the information provided, but for some reason I couldn't get it working in Java. Since this is inevitabily going to be something that others are going to try here is the code that worked for me.

private <T> T restPostFileFormData(String sessionId, String endpoint, ContentBody contentBody, Class<T> returnType) {

try {

URL url = new URL(<baseURL> + endpoint);

HttpURLConnection connection = (HttpURLConnection) url.openConnection();

connection.setDoOutput(true);

connection.setUseCaches(false);

connection.setRequestMethod("POST");

connection.addRequestProperty("token", sessionId);

connection.setRequestProperty("Connection", "Keep-Alive");

connection.setRequestProperty("Cache-Control", "no-cache");

String boundary = "--" + UUID.randomUUID() + "--";

MultipartEntityBuilder builder = MultipartEntityBuilder.create();

builder.setMode(HttpMultipartMode.BROWSER_COMPATIBLE);

builder.setBoundary(boundary);

connection.addRequestProperty("content-type", "multipart/form-data; boundary=" + boundary);

// Binary file content

builder.addPart("file", contentBody);

HttpEntity entity = builder.build();

entity.writeTo(connection.getOutputStream());

connection.connect();

if (connection.getResponseCode() != HttpURLConnection.HTTP_OK) {

throw new InterchangeException(

"Status Code: " + connection.getResponseMessage() +

"\r\nMessage: " + connection.getResponseCode());

}

ObjectMapper mapper = new ObjectMapper();

return mapper.readValue(connection.getInputStream(), returnType);

} catch (Exception e) {

LOG.warn(Utils.getDetailedErrorMessage(e));

}

return null;

}

In order to make this code work you will need to create a Class that is structured like the response. You will also need to correctly input the base URL to get to the application for your needs.