Results 1 to 3 of 3
  1. #1
    bilbodeb is offline Member
    Join Date
    Mar 2009
    Posts
    1
    Rep Power
    0

    Default implementing a console

    Hi all,
    I'm developing an application (within a GUI) that needs to incorporate a system console, that means the application has a text area (jtextpane, jtexteditor, whatever...) in which the user can type commands or watch the output of the different commands.
    I was trying running a proccess as follows:
    Java Code:
                    Process p=Runtime.getRuntime().exec ("cmd");
    		 //and then I catch the output
    		InputStream is = p.getInputStream();
    		InputStream iserror = p.getErrorStream();
    		//and now, the errors (if there are)
    		BufferedReader br = new BufferedReader (new InputStreamReader (is));
    		BufferedReader berr = new BufferedReader (new InputStreamReader (iserror));
                    String aux = berr.readLine();
     
                    while (aux != null){
                           mycode......
                   }
    but this code is only working when I execute command that finish, if I try to execute a command that is waiting the user's answer then it doesn't work (I think readLine() never is reached).

    Can someone help me or give me any idea?
    Thanks in advance.

  2. #2
    Steve11235's Avatar
    Steve11235 is offline Senior Member
    Join Date
    Dec 2008
    Posts
    1,046
    Rep Power
    7

    Default

    If the external process is waiting on the user, then your readLine() may be returning null, as there is nothing to return. Then your program ends.

    You need a better way of determining when the process is complete. You should also put a Thread.sleep() in your while loop. Assume it does more reads...

  3. #3
    toadaly is offline Senior Member
    Join Date
    Jan 2009
    Posts
    671
    Rep Power
    6

    Default

    When reading/writing to process pipes, you generally need to use threads, because InputStream.read blocks.

Similar Threads

  1. IMplementing the DES algo
    By jkuzhuppallil in forum Advanced Java
    Replies: 3
    Last Post: 10-01-2008, 09:24 PM
  2. implementing shape
    By sidkdbl07 in forum Java 2D
    Replies: 1
    Last Post: 01-12-2008, 07:42 PM
  3. Implementing an interface
    By bugger in forum Advanced Java
    Replies: 1
    Last Post: 01-09-2008, 02:35 PM
  4. Implementing more than one interfaces
    By eva in forum New To Java
    Replies: 2
    Last Post: 12-24-2007, 10:50 AM
  5. Implementing and Extending together
    By eva in forum New To Java
    Replies: 2
    Last Post: 12-24-2007, 10:49 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •