http-kit is a minimalist, event-driven, high-performance Clojure HTTP server/client library with WebSocket and asynchronous support
Feign makes writing java http clients easier
The easy HTTP client for Groovy (and Java).
Convenient http client for java, inspired by python request module
Fast Parallel Async HTTP/SSH/TCP/UDP/Ping Client Java Library. Aggregate 100,000 APIs & send anywhere in 20 lines of code. Ping/HTTP Calls 8000 servers in 12 seconds. (Akka) www.parallec.io
a curl-inspired but java based http command line client
Unirest in Java: Simplified, lightweight HTTP client library.
Type-safe HTTP client for Android and Java by Square, Inc.