Reactor Netty
TCP/HTTP/UDP/QUIC client/server with Reactor over Netty
...It directly interacts with Java's functional API, CompletableFuture, Stream, and Duration. Reactor offers two reactive and composable APIs, Flux [N] and Mono [0|1], which extensively implement Reactive Extensions. Well-suited for a microservices architecture, Reactor offers backpressure-ready network engines for HTTP (including Websockets), TCP, and UDP.