Non-blocking read from an InputStream??

Question

Hello all, I have a bit of a problem. I have a GUI based app that, through the mindterm SSH classes, runs a "tail -f /var/log/somelog" command on a *nix server. The purpose of the app is to make looking through the log's easier for the non-computer lay-person. The problem is that if they click the stop button to stop the output of the tail it doesn't actually stop that thread until the next line is appended to the end of the log file. That could be a second or an hour. So what I need is a way to somehow stop that tail -f command when the user hits stop and not have to wait for the read to occur.
What I'm working with is a com.mindbright.util.InputStreamPipe that is a subclass of java.io.InputStream. I've tried several things. Such as the seda.nbio.NonblockingInputStream which gives me a runtime classCastException when trying to cast the com.mindbright.util.InputStreamPipe to a seda.nbio.NonblockingInputStream. I've tried creating a java.nio.channels.ReadableByteChannel and using it's read method but that also blocks.
So my question is, does anyone have any clever solutions to this particular problem? I thought the way to beat it was to find some mechanism to do a read that will just get passed by if there's nothing to read then have it wait an arbitrary amount of time before reading again. So the longest the user would have to wait would be that arbitrary amount of time. But I don't know how to implement this or if it's even a good way to do it.
Thanks in advance!

Answer 1

Thanks for the help dubwai. I actually found a way to accomplish this without any non-blocking balony.
public void run () {
                        try {
                                java.io.InputStream is = tbs.getConsoleOut();
                                java.io.BufferedReader in = new java.io.BufferedReader(new java.io.InputStreamReader(is));
                                String line = null;
                                // continue is a volatile boolean that gets set to false when user clicks stop
                                while ( cont ) {
                                        if ( is.available() > 0 ) {
                                                line = in.readLine();
                                                System.out.println("in while: "+line);
                                        } // end
                                        else {
                                                try {
                                                        java.lang.Thread.sleep(500);
} // end try
                                                catch ( java.lang.InterruptedException ie ) {
                                                        System.err.println("Error sleeping: "+ie);
                                                } // end catch
                                        } // end else
                                } // end while
                                is.close(); in.close();
                                System.out.println("After while");
                                System.exit(0);
                        } // end try
                        catch ( Exception e ) {
                                System.err.println("Error reading lines: "+e);
                        } // end catch
                } // end runThis seems to work on a few trial runs.. Does anyone see any possible random timing issues from this??