Sending telnet commands and reading the response with Java [closed]

Answer 1

The problem with doing it down at the socket level is that you suddenly need to be a protocol expert, when all you want to do is a few telnet commands.

I wrote a driver on top of de.mud.jta, but it leaves threads open, and I don't know where, and how to fix those. Seems to me that there must be something better out there than coding at the protocol level or this old JTA stuff.

Answer 2

Why don't you simply use the Socket system ?

Open a socket to the chosen server on port 23 and send your own commands from here.

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Here is a quick example :

public class EchoClient {
    public static void main(String[] args) throws IOException {

        Socket pingSocket = null;
        PrintWriter out = null;
        BufferedReader in = null;

        try {
            pingSocket = new Socket("servername", 23);
            out = new PrintWriter(pingSocket.getOutputStream(), true);
            in = new BufferedReader(new InputStreamReader(pingSocket.getInputStream()));
        } catch (IOException e) {
            return;
        }

        out.println("ping");
        System.out.println(in.readLine());
        out.close();
        in.close();
        pingSocket.close();
    }
}

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Resources :

• oracle.com - All about sockets

Answer 3

Try Checking Netty Java Library. they have a good set of Telnet , SSH and other very useful network library

https://netty.io

Answer 4

Expect is a scripted (non-Java) possibility. It's an older tool, see the Pros and Cons at Wikipedia.

Answer 5

telnet is almost bare tcp. you can probably make a socket connection, write commands, read responses.

well - telnet does have some control commands that can be mixed with data stream. you can probably program to ignore them. or, to be perfectly protocol aware, use a java telnet client package.