How to customise "Invalid CORS request" message thrown by Spring DefaultCorsProcessor?

Question

When we enable CORS for a Spring Boot application, it throws "Invalid CORS request" message for the REST API calls with invalid origin header. This is thrown by DefaultCorsProcessor's below method. Is there a way to customize this message?

protected void rejectRequest(ServerHttpResponse response) throws IOException {
        response.setStatusCode(HttpStatus.FORBIDDEN);
        response.getBody().write("Invalid CORS request".getBytes(StandardCharsets.UTF_8));
        response.flush();
}

Tried various options like custom exception handler but didn't help.

Answer 1

I think you could inject a custom CorsProcessor like that:

    import java.io.IOException;
    
    import org.springframework.boot.autoconfigure.web.servlet.WebMvcRegistrations;
    import org.springframework.http.server.ServerHttpResponse;
    import org.springframework.stereotype.Component;
    import org.springframework.web.cors.DefaultCorsProcessor;
    import org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping;
    
    @Component
    public class CustomWebMvcRegistrations implements WebMvcRegistrations {
        @Override
        public RequestMappingHandlerMapping getRequestMappingHandlerMapping() {
            RequestMappingHandlerMapping rhm = new RequestMappingHandlerMapping();
            rhm.setCorsProcessor(new DefaultCorsProcessor() {
                @Override
                protected void rejectRequest(ServerHttpResponse response) throws IOException {
                    // DO WHATEVER YOU WANT
                    super.rejectRequest(response);
                }
            });
            return rhm;
        }
    }