Vert.x Simple Telnet Server - NIO Server

gistfile1.groovy

// general configuration
settings = [port: 1234];

// Vert.x server and event-bus
def server = vertx.createNetServer()
def bus = vertx.eventBus

// Connection handler. Here requests are captured, parsed, and executed.
server.connectHandler { sock ->
    // upon a new connection, assigning a new connection id (cid)
    String cid = registerConnection();
    println "[$cid]# got a new connection id: $cid - currently ${_connections.size()} are alive.";

    // welcome the user with a message
    sock.write(welcome())

    // handle the connection close.
    sock.closedHandler { 
        _connections.remove(cid); 
        println "[$cid]# The connection is now closed"
    }

    // handle incoming requests from a single connection
    // a request, might contains multiple commands, splitting them by line.
    sock.dataHandler { buffer ->
        def lines = new String(buffer.bytes).trim().split("\r\n").collect { it.trim() }
        lines.each {
            println "[$cid]> $it"
            if (it == "") return

            // if a command is found send it to the commands-handler
            bus.send("commands", [command: it, cid: cid]) {
                resp ->
                // once you get a response for a command
                // then send it back to the user
                String outMessage = prepareOutput(resp.body.message)
                if (outMessage != "") {
                    sock.write("$outMessage\r\n") {
                        println "[$cid]< " + outMessage.replaceAll("\n", "\n[$cid]< ")
                    }
                }

                // if the command was "quit", close the connection.
                if (resp.body.status == "ACTION" && resp.body.action == "QUIT")
                    sock.close()
            }
        }
    }
}.listen( settings.port );

println """
---------------------------------------------------------------------
                   Simple Vert.x Telnet Server
---------------------------------------------------------------------
(*) Server started at $BASE_DIR and listening on port: $settings.port
"""