Passing Ping Command Through Telnet

[ranua agarwal]

HI,
I am using following program to ping a remote server--

import java.io.InputStream;
import java.io.PrintStream;

import org.apache.commons.net.telnet.TelnetClient;

public class Test {
	
	private TelnetClient telnet = new TelnetClient();
	private InputStream in;
	private PrintStream out;
	private String prompt = "#";

	public Test(String server, String user, String password) {
		try {
			// Connect to the specified server
			telnet.connect(server, 22);

			// Get input and output stream references
			in = telnet.getInputStream();
			out = new PrintStream(telnet.getOutputStream());

			// Log the user on
			readUntil("login: ");
			write(user);
			readUntil("Password: ");
			write(password);

			// Advance to a prompt
			readUntil(prompt + " ");
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public void su(String password) {
		try {
			write("su");
			readUntil("Password: ");
			write(password);
			prompt = "#";
			readUntil(prompt + " ");
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public String readUntil(String pattern) {
		try {
			char lastChar = pattern.charAt(pattern.length() - 1);
			StringBuffer sb = new StringBuffer();
			boolean found = false;
			char ch = (char) in.read();
			while (true) {
				System.out.print(ch);
				sb.append(ch);
				if (ch == lastChar) {
					if (sb.toString().endsWith(pattern)) {
						return sb.toString();
					}
				}
				ch = (char) in.read();
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}

	public void write(String value) {
		try {
			out.println(value);
			out.flush();
			System.out.println(value);
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public String sendCommand(String command) {
		try {
			write(command);
			return readUntil(prompt + " ");
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
	}

	public void disconnect() {
		try {
			telnet.disconnect();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	public static void main(String[] args) {
		try {
			Test telnet = new Test("144.188.99.12", "user_name", "pwd");
			telnet.sendCommand("ping");
			telnet.disconnect();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}    

But i am getting this output :
SSH-2.0-4.1.0.34 SSH Secure Shell

Can anybody point out where is the problem?

Thanks,
Ranu.

[Sagar Rohankar]

Have you consult the JavaDocs for the same ?

[Rob Spoor]

You are using SSH (port 22) but treat it as Telnet. That's not going to work. Either switch to port 23, or use an SSH client.

[ranua agarwal]

Thank you Rob for the response.
Well, i changed the port as 23, but getting exception--

java.net.ConnectException: Connection refused: connect
	at java.net.PlainSocketImpl.socketConnect(Native Method)
	at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
	at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
	at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
	at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
	at java.net.Socket.connect(Socket.java:516)
	at java.net.Socket.connect(Socket.java:466)
	at java.net.Socket.<init>(Socket.java:366)
	at java.net.Socket.<init>(Socket.java:179)
	at org.apache.commons.net.DefaultSocketFactory.createSocket(DefaultSocketFactory.java:53)
	at org.apache.commons.net.SocketClient.connect(SocketClient.java:162)
	at com.text.Test.<init>(Test.java:18)
	at com.text.Test.main(Test.java:102)
java.lang.NullPointerException
	at com.text.Test.write(Test.java:73)
	at com.text.Test.sendCommand(Test.java:84)
	at com.text.Test.main(Test.java:103)
java.lang.NullPointerException
	at com.text.Test.readUntil(Test.java:54)
	at com.text.Test.sendCommand(Test.java:85)
	at com.text.Test.main(Test.java:103)
java.lang.NullPointerException
	at org.apache.commons.net.telnet.TelnetClient.disconnect(TelnetClient.java:125)
	at com.text.Test.disconnect(Test.java:94)
	at com.text.Test.main(Test.java:104)

As you suggested, now i am looking for SSH client. Meanwhile is there any api available that implemented this?

Thank you Sagar for showing interest in the problem.
Well, i went through java docs, but not in depth.
Anything mising?

[ranua agarwal]

Can Mbean will be another choice?

[Rob Spoor]

ranua agarwal wrote:Thank you Rob for the response.
Well, i changed the port as 23, but getting exception--

java.net.ConnectException: Connection refused: connect

That means that Telnet is not enabled, and SSH is your only option.

As you suggested, now i am looking for SSH client. Meanwhile is there any api available that implemented this?

java ssh