How to check if an HTTPS URL redirects to an HTTP URL?

Question

I have a list of HTTPS URLs and I want to make sure they are accessible. I use HttpURLConnection to follow redirects by checking for any 300/301/302 responses, following the redirect, and so on until I get a 200 or anything else.

How do I check along the way that none of the redirects are to a HTTP (non-secure) endpoint?

Does it ever fail if the redirect from an HTTPS goes to HTTP, or do I have to manually check?

Answer 1

HttpURLConnection won't follow redirects when switching protocol (http -> https, https -> http). So you'll know when such redirects happen. If you want to be 100% safe, call

• HttpURLConnection.setFollowRedirects(false) or
• conn.setInstanceFollowRedirects(false) .