A lib I've used often lately is Project Lombok. Lombok fills the gap between Java and some C# syntactic sugar features that makes me slightly jealous ;).

There are a lot of HTTP libraries available in the Java universe like the Apache HttpClient library. Also Java provides the HttpURLConnection class as a standard on-board. They all have in common that I (and thats just my humble opinion ;)) don't like them really because they feel like a way back in 2001.

This tutorial shows how to create a simple web server with a tiny REST "API" and a PostgreSQL database. I asume that you have installed the node.js platform and npm. I'm going to use the node-postgres client to connect to the PostgreSQL database. The installation is easily done with npm.