How to get Spring Boot to map query parameters separately from form data? - spring-boot

Question

#RequestMapping(value = "/**", consumes = MediaType.ALL_VALUE)
#ResponseBody
public Object mirror(HttpServletRequest req, #Nullable #RequestBody Map<String, String> form) {
...
}
I just want the plain key and value for all form data entries here but it also includes query parameters in the map.
I need to be able to tell the difference between what came from the form and what came from the query.
Getting the query parameters separately is easily done using URI parsing but it's not so easy to remove the query parameters from the form map. Especially in the case they have the same keys.
Changing the parameter to MultiValueMap adds values with the same key into an array. Using just a Map causes the query parameters to overwrite the form data with equal keys.
I found where this is happening, for the MockHttpServletRequest at least: buildRequest method:
String query = this.url.getRawQuery();
if (!this.queryParams.isEmpty()) {
String s = UriComponentsBuilder.newInstance().queryParams(this.queryParams).build().encode().getQuery();
query = StringUtils.isEmpty(query) ? s : query + "&" + s;
}
if (query != null) {
request.setQueryString(query);
}
addRequestParams(request, UriComponentsBuilder.fromUri(this.url).build().getQueryParams());
this.parameters.forEach((name, values) -> {
for (String value : values) {
request.addParameter(name, value);
}
});
It's combining the form data and query data into one map. So is there an alternative way to parse the form data ONLY or exclude query params from the map!?

Answer 1

From the javadoc for #RequestParam:
In Spring MVC, "request parameters" map to query parameters, form data, and parts in multipart requests. This is because the Servlet API combines query parameters and form data into a single map called "parameters", and that includes automatic parsing of the request body.
Not sure if there's a more elegant way, but you could possibly use Spring's UriComponentsBuilder class to parse the URI string and get back the query parameters.