Feign 10.1, '+' in query param is not encoded

[grusell]

I would expect a '+' inside a query parameter value to be encoded to '%2B'. With feign 10.1, it seems the '+' is left untouched when the param is encoded.

[cecchisandrone]

I noticed the same while migrating from 9.3.1 to 10.0.1.

In particular the suspect code is in UriUtils:

private static String urlEncode(String value, Charset charset) {
    try {
      String encoded = URLEncoder.encode(value, charset.toString());

      /*
       * url encoding is not equivalent to URI encoding, there are few differences, namely dealing
       * with spaces, !, ', (, ), and ~ characters. we will need to manually process those values.
       */
      return encoded.replaceAll("\\+", "%20")
          .replaceAll("\\%21", "!")
          .replaceAll("\\%27", "'")
          .replaceAll("\\%28", "(")
          .replaceAll("\\%29", ")")
          .replaceAll("\\%7E", "~")
          .replaceAll("\\%2B", "+");

    } catch (UnsupportedEncodingException uee) {
      /* since the encoding is not supported, return the original value */
      return value;
    }

For example the value +asd for a path parameter is first encoded to %2Basd and after restored to +asd.

I think this must considered duplicate of #879

[kdavisk6]

It is a duplicate. It has been fixed via #882