RequestContextHolder support for reactive Spring Applications

ReactiveRequestContextFilter.java

import lombok.extern.slf4j.Slf4j;
import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import org.springframework.web.server.WebFilter;
import org.springframework.web.server.WebFilterChain;
import reactor.core.publisher.Mono;
import reactor.util.context.Context;

@Component
@Order(value = Ordered.HIGHEST_PRECEDENCE)
@ConditionalOnWebApplication(type = ConditionalOnWebApplication.Type.REACTIVE)
public class ReactiveRequestContextFilter implements WebFilter {

    @Override
    public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
        ServerHttpRequest request = exchange.getRequest();
        return chain.filter(exchange)
                .contextWrite(ctx -> ctx.put(ReactiveRequestContextHolder.CONTEXT_KEY, request));
    }
}

ReactiveRequestContextHolder.java

import org.springframework.http.server.reactive.ServerHttpRequest;
import reactor.core.publisher.Mono;

public class ReactiveRequestContextHolder {
    public static final Class<ServerHttpRequest> CONTEXT_KEY = ServerHttpRequest.class;

    public static Mono<ServerHttpRequest> getRequest() {
        return Mono.deferContextual(ctx ->
                Mono.just(ctx.get(CONTEXT_KEY)));
    }
}