Problem running putty.exe in a seperate thread

Question

Hi All - I have an issue when using a new thread to run an external .exe file (Putty in this case)
When I don't use a new thread Putty will start and stay open and let me do what I need to as normal, however it then hangs the rest of the application so you can't use it until you are finished with Putty - So I thought I would put it in a new thread. I use this method quite a bit in my application and don't have any issues so i'm wondering what I have done wrong here, I call other external .exe files and also start some external Java processes using a new thread and they work OK (using the same method)
It seems to me that the putty process doesn't seem to give any output and so the thread assumes it has closed and shuts down, or I need to inform the thread to wait and send it a message to clean up when I am finished. If I connect to a host and need to add the RSA key to the cache then Putty will stay open in the new thread until I click OK to save the key, then as soon as I have done that it closes
Can anyone point me in the right direction?
Below is some code for working and not working scenarios, the code below has been altered to run from a button click as in my app it's done from a popup menu and I don't think the issue is with the calling function (but I could be wrong)......
Working:
    private void jbtnTestButtonActionPerformed(java.awt.event.ActionEvent evt) {                                              
        try {
            String myPuttyDir;
            File myFile = new File("C:\\Putty\\putty.exe");
            myPuttyDir = myFile.toString();   
            String myPuttyArgs = " -ssh [email protected] -pw PASSWD";
            String myProcStart = myPuttyDir + myPuttyArgs;
            Process proc = Runtime.getRuntime().exec(myProcStart);
            BufferedReader bri = new BufferedReader(new InputStreamReader(proc.getInputStream()));
            BufferedReader bre = new BufferedReader(new InputStreamReader(proc.getErrorStream()));
            String line;
            while ((line = bri.readLine()) != null) {
                System.out.println(line);
            bri.close();
            while ((line = bre.readLine()) != null) {
                System.out.println(line);
            bre.close();
            proc.waitFor();
            System.out.println("Putty Closed!");         
            catch (Exception ex)
                System.out.println("Exception error :"+ex.getMessage());
                ex.printStackTrace();
       //no issue with this method, putty stays open until I close it and then it prints the closed message and exits cleanly
    }And here is the code with a new thread:
private void jbtnTestButtonActionPerformed(java.awt.event.ActionEvent evt) {                                              
        final Thread t = new Thread() {
            public void run() {
                try {
                   String myPuttyDir;
                    File myFile = new File("C:\\Putty\\putty.exe");
                    myPuttyDir = myFile.toString();
                    String myPuttyArgs = " -ssh [email protected] -pw PASSWD";
                    String myProcStart = myPuttyDir + myPuttyArgs;
                    Process proc = Runtime.getRuntime().exec(myProcStart);
                    BufferedReader bri = new BufferedReader(new InputStreamReader(proc.getInputStream()));
                    BufferedReader bre = new BufferedReader(new InputStreamReader(proc.getErrorStream()));
                    String line;
                    while ((line = bri.readLine()) != null) {
                        System.out.println(line);
                    bri.close();
                    while ((line = bre.readLine()) != null) {
                        System.out.println(line);
                    bre.close();
                    proc.waitFor();
                    System.out.println("Putty Closed!");
                } catch (Exception ex) {
                    System.out.println("Exception error :" + ex.getMessage());
                    ex.printStackTrace();
        t.start();//start the thread
        //This method opens Putty for a second, you just see it, and then it closes
}   Thanks in advance for any help! I'm new to threading in Java having come from a .NET environment and I think I need to listen to the thread somehow but i'm a bit lost......

Answer 1

Hi Gimbal2 - google is my friend (other search engines are available.....) and I have looked at loads of results but none of them gets close to what i'm looking for, nearly all the telnet/ssh libraries don't do interactive window stuff (although I admit I do want the moon on a stick....)
The best I looked at so far is Gritty (seems to be base on JSch terminal) but it just can't handle telnet or ANSI formatting and doesn't do VT100 emulation, although the plain SSH terminal is OK and usable
The rest are SSH/Telnet libraries and I will need to write a terminal emulator and some other stuff to make them do what I need....TBH i'm not good enough a programmer to do that. I just make small apps that make my life at work easier (and also my work mates) i'm not a professional programmer and nothing is for commercial reasons
I use the Reflections .NET control in my old .NET app and it has absolutely everything built in, all functions of Reflections are callable via native code so it makes life so easy - I was hoping for that kind of solution in Java, because basically i'm lazy!! The reason is that the equipment I connect to uses Telnet and SSH but they aren't 'normal' servers as such, I work in 'comms and each vendor has their own language that you need to use over the Telnet/SSH session so I need a plain terminal emulator that handles XTERM/VT100/VT102, ANSI etc. Reflections did this for me and had a great way to send commands in just about any format and then store results etc
Anyway - apologies if i've been spamming the forum with stupid questions, I do try to work through google answers before posting here....
BTW, I tried the google search with SSH terminal and got way more/better results than searching for "Java Telnet" or "Java Terminal Emulator" so am going to have a look at some of those as well, thanks for your help!
Edited by: Matt_C on Oct 25, 2012 6:07 AM