Java Networking

This page collects clients, servers and utilities useful for implementing networking functionality in Java and Android

Active Directory

DDC

CIFS

The jCIFS client library is obsolete, use jcifs-ng instead. This also works on Android.
smbj

DNS

DNSJava (client library, also works on Android and supports DoH)
JmDNS implements multi-cast DNS. It supports service discovery and service registration. It is fully interoperable with Apple's Bonjour.
RxDNSSD implements DNS-SD for Android, addressing some issues with Android's built-in JavaDoc:android.net.nsd.NsdManager

FTP

Apache Mina (server)

HTTP

Apache Tomcat (server)
Eclipse Jetty (server)
OkHttp (client library)

Guide to OkHttp

Apache HttpComponents (client library)
Apache Commons FileUpload (server library for handling file uploads)
Using the HttpClient and FileUpload libraries together
sardine and JackRabbit are (or have) WebDAV client libraries

Mail

Aspirin, a send-only SMTP server
James, an email server written in Java
Jakarta Mail, a mail client library
java-utils-mail-dkim adds DKIM support to Jakarta Mail

SNMP

SNMP4J

Introduction

SSH

UPnP

clinq, a client library for Java and Android

Android-uPnP-Discovery, an app that shows how to use clinq on Android

Wake-on-LAN or WOL

MagicPacket is an Android app, but the networking part is universally applicable

Miscellaneous

Apache Commons Net is a client library for many protocols: FTP/FTPS, FTP over HTTP (experimental), NNTP, SMTP(S), POP3(S), IMAP(S), Telnet, TFTP, Finger, Whois, rexec/rcmd/rlogin, Time (rdate) and Daytime, Echo, Discard, NTP/SNTP

WhoisLookup is a more full-fledged Whois client based on Commons Net

Apache Commons Validator has some useful validation routines

IPAddress is a library for handling IP addresses and subnets, both IPv4 and IPv6
Ping & Net implements many networking clients in a single handy Android app written by me :-)
Get the Mime Type from a File

Transparently improve Java 7 mime-type recognition with Apache Tika