Introduce `shouldFilter` in `OncePerRequestFilter`

[sic2]

Hi, I was thinking whether it makes sense to add a boolean shouldFilter(HttpServletRequest request) method in OncePerRequestFilter.

Why

Today, shouldNotFilter can be used to block filtering on specific requests.
The introduction of shouldFilter would enable for more intentional filtering.

public class BookingsFilter extends OncePerRequestFilter {
    
    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response,
				FilterChain filterChain) { ... }

    @Override
    protected boolean shouldFilter(HttpServletRequest request) throws ServletException {
        return request.getRequestURI().startsWith("/booking");
    }
}

Pseudo-implementation

protected boolean shouldFilter(HttpServletRequest request) throws ServletException {
	return true;
}

In the situation that a request is satisfied by both shouldNotFilter and shouldFilter, the shouldNotFilter will take precedence. Changes in the doFilter method would be:

- else {
+ else if (shouldFilter(httpRequest)) {
	 // Do invoke this filter...
	 request.setAttribute(alreadyFilteredAttributeName, Boolean.TRUE);

Contributing

I am happy to take this on, provided the idea is accepted.

[sic2]

I have taken some initiative, opened PR:

• Introduce shouldFilter flag in OncePerRequestFilter #35612

[sbrannen]

• Superseded by Introduce shouldFilter flag in OncePerRequestFilter #35612