fix: now handling more HTTP redirect types

We were handling only a limited set of redirect types, this has now been
extended to include all common and not so common 3xx redirect codes.
This includes the somewhat strange 303 See Other where the spec isn't
completely clear but the general concensus seems to be that it forces
the next request to be a GET request.

Fixes #1769

src/main/java/dev/jbang/util/Util.java

@@ -1063,16 +1063,16 @@ private static String extractFileName(URLConnection urlConnection) throws IOExce
  // extracts file name from header field
  fileName = getDispositionFilename(disposition);
  }
- if (isBlankString(fileName)) {
- // extracts file name from URL if nothing found
- int p = fileURL.indexOf("?");
- // Strip parameters from the URL (if any)
- String simpleUrl = (p > 0) ? fileURL.substring(0, p) : fileURL;
- while (simpleUrl.endsWith("/")) {
- simpleUrl = simpleUrl.substring(0, simpleUrl.length() - 1);
- }
- fileName = simpleUrl.substring(simpleUrl.lastIndexOf("/") + 1);
+ }
+ if (isBlankString(fileName)) {
+ // extracts file name from URL if nothing found
+ int p = fileURL.indexOf("?");
+ // Strip parameters from the URL (if any)
+ String simpleUrl = (p > 0) ? fileURL.substring(0, p) : fileURL;
+ while (simpleUrl.endsWith("/")) {
+ simpleUrl = simpleUrl.substring(0, simpleUrl.length() - 1);
  }
+ fileName = simpleUrl.substring(simpleUrl.lastIndexOf("/") + 1);
  }
  } else {
  fileName = fileURL.substring(fileURL.lastIndexOf("/") + 1);
@@ -1087,17 +1087,27 @@ private static HttpURLConnection handleRedirects(HttpURLConnection httpConn, Con
  while (true) {
  httpConn.setInstanceFollowRedirects(false);
  responseCode = httpConn.getResponseCode();
- if (responseCode == HttpURLConnection.HTTP_MOVED_PERM ||
+ if (responseCode == HttpURLConnection.HTTP_MULT_CHOICE ||
+ responseCode == HttpURLConnection.HTTP_MOVED_PERM ||
  responseCode == HttpURLConnection.HTTP_MOVED_TEMP ||
- responseCode == 307 /* TEMP REDIRECT */) {
+ responseCode == HttpURLConnection.HTTP_SEE_OTHER ||
+ responseCode == 307 /* TEMP REDIRECT */ ||
+ responseCode == 308 /* PERM REDIRECT */) {
  if (redirects++ > 8) {
  throw new IOException("Too many redirects");
  }
  String location = httpConn.getHeaderField("Location");
+ if (location == null) {
+ throw new IOException("No 'Location' header in redirect");
+ }
  URL url = new URL(httpConn.getURL(), location);
  url = new URL(swizzleURL(url.toString()));
  verboseMsg("Redirected to: " + url); // Should be debug info
  httpConn = (HttpURLConnection) url.openConnection();
+ if (responseCode == HttpURLConnection.HTTP_SEE_OTHER) {
+ // This response code forces the method to GET
+ httpConn.setRequestMethod("GET");
+ }
  configurator.configure(httpConn);
  continue;
  }