Execute command on remote linux and return output?

Question

Guys,
I'm new to Java and still working hard on my way thru.
I used a client software "putty" to logon to a linux machine. as the window is exactly like what it is in linux. in "/proc" I typed in "grep cpu stat" which returned 2 lines result of the cpu status on the screen.
now, I have to do the same thing in Java. To execute a line of command "grep cpu stat" on the remote linux. then return the 2 lines result to my code and store them in string variebles. Can anyone please help me with this and show me some sample code of doing this Please.
Thanks, and thanks big time
, Jimbo

Answer 1

Hi,
look at this code, maybe it will help you...
//this is only method
public int exec(String[] command, OutputStream outStream) {
     Process p;
     int exitValue = -1;
     ByteArrayOutputStream tmpErr = new ByteArrayOutputStream(OUTPUT_BUFFER_SIZE);
     try {
          p = Runtime.getRuntime().exec(command);
          BufferedInputStream out = new BufferedInputStream(p.getOutputStream());
          ThreadStreamPumper pumper = new ThreadStreamPumper(out, tmp);               pumper.start();
          p.waitFor();
          exitValue = p.exitValue();
          pumper.join();
          out.close();
          p.destroy();
          tmp.close();
          tmp.writeTo(outStream);
     } catch (IOException ioe) {
          return -3;
     } catch (InterruptedException ie) {
          return -4;
     boolean isOkay = exitValue == 0;
     if (tmp.size() > 0) {
          return -5;
     return exitValue;
//this is class
*  class for continually pumping the input stream during Process's
*  runtime.
class ThreadStreamPumper extends Thread {
     private BufferedInputStream stream;
     private boolean endOfStream = false;
     private boolean stopSignal = false;
     private int SLEEP_TIME = 5;
     private OutputStream out;
      *  Creates new <code>ThreadStreamPumper</code>
      *@param  is   From where to pump datas
      *@param  out  Where to send datas
     public ThreadStreamPumper(BufferedInputStream is, OutputStream out) {
          this.stream = is;
          this.out = out;
      *  Gets datas from <code>in</code> and sends them to <code>out</code>.
      *@exception  IOException  When some IO error occurs
     public void pumpStream()
           throws IOException {
          byte[] buf = new byte[BUFFER_SIZE];
          if (!endOfStream) {
               int bytesRead = stream.read(buf, 0, BUFFER_SIZE);
               if (bytesRead > 0) {
                    out.write(buf, 0, bytesRead);
               } else if (bytesRead == -1) {
                    endOfStream = true;
      *  Main processing method for the <code>ThreadStreamPumper</code>
     public void run() {
          try {
               //while (!endOfStream || !stopSignal) {
               while (!endOfStream) {
                    pumpStream();
                    sleep(SLEEP_TIME);
          } catch (InterruptedException ie) {
          } catch (IOException ioe) {