Re: Socket with setSoTimeout() never times out

On Fri, 29 Feb 2008 06:22:40 -0800 (PST), phillip.s.powell@gmail.com wrote:


Perhaps. So you're trying to avoid invoking the MailAdminReader method
by testing first whether the machine is up?

Perhaps try something like this:

  try {
    Socket s = new Socket(); // note: unconnected
    // choose the *same* port here as mailAdminReader uses! 25, 110, 143 etc
    s.connect(new InetSocketAddress(addr, port), 5000);
    s.close();
    hasMail = mailAdminReader.checkMail();
  }
  catch (SocketTimeoutException) {
    // no response
  }

Or use a separate thread:

  public class MyRunnable implements Runnable {
    private boolean hasMail = false;
    private boolean gotResponse = false;

    public boolean gotResponse() {
      return gotResponse;
    }

    public boolean hasMail() {
      return hasMail;
    }

    public void run() {
      try {
        hasMail = mailAdminReader.checkMail();
        gotResponse = true;
      }
      catch (Exception e) {
        // no response
      }
    }
  }

Then:

  MyRunnable mr = new MyRunnable();
  Thread t = new Thread(mr);
  t.start();
  t.join(5000);
  if (mr.gotResponse()) {
    hasMail = mr.hasMail();
  }


Not knowing JSP, I'll hazard a guess and say the same way you'd do it
in an application.

Both of these techniques should work. The first one won't catch
situations where the mailAdminReader blocks for other reasons. The
second one will leave the thread dangling until the mailAdminReader
eventually times out, you just don't need to block waiting for that to
happen.

/gordon

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