[NET-350] "java.net.SocketException: Broken pipe" when calling "TelnetClient.sendAYT()"

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.2
• Fix Version/s: 3.0
• Component/s: Telnet

Environment

Ubuntu 10.10 (x32)
Java JDK 1.6.0.22

• Assignee: Unassigned
• Reporter: Age Bosma
• Created: 16/Jan/11 16:43
• Updated: 04/Jun/11 19:26
• Resolved: 10/Mar/11 02:31

Description

I'm trying to write some code to have a reliable way to determine if a telnet connection is still available and not closed on the remote server. Even though I first call TelnetClient.isConnected(), the followed TelnetClient.sendAYT() gives me SocketException. The problem occurs when I provide invalid login credentials on purpose when logging in to the telnet server.

Code snippet:

    private boolean isConnected() {
        return isConnected(100);
    }

    private boolean isConnected(int timeOut) {
        boolean connected = false;

        if (telnetClient.isConnected()) {
            try {
                connected = telnetClient.sendAYT(timeOut);
            } catch (IOException ex) {
                Logger.getLogger(ForceLogin.class.getName()).log(Level.SEVERE, null, ex);
            } catch (IllegalArgumentException ex) {
                Logger.getLogger(ForceLogin.class.getName()).log(Level.SEVERE, null, ex);
            } catch (InterruptedException ex) {
                Logger.getLogger(ForceLogin.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
        
        System.out.println("Still connected? " + connected);

        return connected;
    }

What I do is execute the following:

succesfulLogin = forceLogin.isConnected();

if (succesfulLogin) {
        succesfulLogin = forceLogin.isConnected(1000);
}

When I try to fail the telnet login (providing invalid credentials), the first "isConnected()" call sometimes gives me TRUE, sometimes gives me FALSE. When it's TRUE I want to make sure that we are really still connected using a longer "TelnetClient.sendAYT()" timeout. This is where the exception occurs.

Resulting exception:

16-Jan-2011 16:44:04 force.ForceLogin isConnected
SEVERE: null
java.net.SocketException: Broken pipe
        at java.net.SocketOutputStream.socketWrite0(Native Method)
        at java.net.SocketOutputStream.socketWrite(SocketOutputStream.java:92)
        at java.net.SocketOutputStream.write(SocketOutputStream.java:136)
        at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:65)
        at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:123)
        at org.apache.commons.net.telnet.Telnet._sendAYT(Telnet.java:1095)
        at org.apache.commons.net.telnet.TelnetClient.sendAYT(TelnetClient.java:206)
        at force.ForceLogin.isConnected(ForceLogin.java:95)
        at force.ForceLogin.main(ForceLogin.java:160)