The Apache Commons Net library implements the client side of many basic
 Internet protocols. The purpose of the library is to provide fundamental
 protocol access, not higher-level abstractions. Therefore, some of the
 design violates object-oriented design principles. The philosophy is to
 make the global functionality of a protocol accessible (e.g., TFTP send
 file and receive file) when possible, but also provide access to the
 fundamental protocols where applicable so that a programmer may construct
 his own custom implementations (e.g, the TFTP packet classes and the TFTP
 packet send and receive methods are exposed).
 .
 The supported protocols include:
  * 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