如何防止自动解码 Spring controller 中的 RequestParam 字符串

Question

I have an HTTP GET request controller endpoint where I take in a fileName as a query param and pass that on to another service. For this request the param the filename could include any sort of special characters and I would like to keep these values encoded when passing them on. 2 Characters that have been causing issues are spaces (%20) and +(%2B).

How can I keep these characters encoded in the request params.

So far I have tried using the @RequestParam annotation as well as retrieving the params via HttpServletRequest.getParameterValues(String) but both return the decoded values as spaces.

Any help is appreciated thanks!

Answer 1

Yes, these are automatically decoded by the servlet API. You should be able to re-encode them -

encodedValue = URLEncoder.encode(value, StandardCharsets.UTF_8);

Answer 2

I found out that I could get the actual value passed in by using the HttpServletRequest.getQueryString() method. Parsing this query string I was able to get the un-decoded version of the fileName being passed in. I hope this helps someone in the future.