URL is accessable with browser but still FileNotFoundException with URLConnection

Question

I use a HttpURLConnection to connect to a website and receive an ResponseCode=404 (HTTP_NOT_FOUND). However I have no problem opening the website in my browser (IE).

Answer 1

I had a similar scenario where the web service processed POST requests from the browser (in my case Postman, an API testing Chrome extension) correctly, but HttpURLConnection kept failing with a 404 for large payloads. I mistakenly assumed that the problem must be in my HttpURLConnection client code.

When I later tried to replicate the request from cUrl with a large payload, I got the same 404 error. Even though I used the cUrl code generated by Postman, which therefore should be identical to Postman's request, there was a difference in how the web service reacted to both requests. Some client middleware on Postman may have intercepted and modified the requests.

TL;DR

Check the web service. It may be the culprit. Try another non-browser barebones Http client like cUrl to see how the web service reacts to it.