Running Interactive commands in java and displaying the output.

Question

Hi All,
I'm running a sample code to execute a user defined command (cmd1) and display the results. The output of the command when executed in command prompt is
(1) Executing the command cmd1
(2) Do you want to continue(Y/N)_ <waits for user input>
(3) Based on user input
(Y) Displays the results
(N) Interrupted
But i'm facing problem when i execute the below code. When the results are being displayed instead of displaying line(1) and (2) and then waiting for the input- the code waits for the input and then only displays the results.
O/p
inside output
inside input
y (------ gets the input and then only displays the results).
Executing the command cmd1
Do you want to continue(Y/N)
results
Please help out how to resolve this issue.
Thanks.
Sample Code for reference.
import java.util.*;
import java.io.*;
public class SampleCheck {
     public static void main(String[] args) throws Exception {
          (new SampleCheck()).test();
     void test() throws Exception {
          Process proc = Runtime.getRuntime().exec("cmd1");
          // any error from the process?
          StreamHandlerErr errorStream = new StreamHandlerErr(proc
                    .getErrorStream(), System.err);
          // any output from the process?
          StreamHandlerOutput outputStream = new StreamHandlerOutput(proc
                    .getInputStream(), null);
          // any input to the process?
          // FileInputStream fin = new FileInputStream(new File("textfile1.txt"));
          StreamHandlerInput inputStream = new StreamHandlerInput(System.in, proc
                    .getOutputStream());
          // start the stream threads
          // errorStream.start();
          outputStream.start();
          inputStream.start();
          // wait till it returns
          int exitVal = proc.waitFor();
          System.exit(exitVal);
     class StreamHandlerInput extends Thread {
          InputStream is;
          OutputStream os;
          StreamHandlerInput(InputStream is, OutputStream os) {
               this.is = is;
               this.os = os;
          public void run() {
               System.out.println("inside input");
               try {
                    int c;
                    while ((c = is.read()) != -1) {
                         os.write(c);
                         System.out.println("c= " + c);
                         os.flush();
               } catch (IOException e) {
               System.out.println("End of Run Method..Input");
     class StreamHandlerOutput extends Thread {
          InputStream is;
          OutputStream os;
          File f=new File("jbsrt_output.txt");
          StreamHandlerOutput(InputStream is, OutputStream os) {
               this.is = is;
               this.os = os;
          public void run() {
               System.out.println("inside output");
               try {
                    int c;
                    FileOutputStream fs=new FileOutputStream(f);
                    /*PrintStream ps =new PrintStream(;
                    ps.print(arg0)
                    ps.close();*/
                    InputStreamReader ir = new InputStreamReader(is);
                    //System.out.println(ir.read());
                    BufferedReader br = new BufferedReader(ir);
                    String line = null;
                    while((line=br.readLine())!=null)
                         System.out.println(line);
               } catch (Exception e) {
               System.out.println("End of Run Method..Output");
     class StreamHandlerErr extends Thread {
          InputStream is;
          OutputStream os;
          StreamHandlerErr(InputStream is, OutputStream os) {
               this.is = is;
               this.os = os;
          public void run() {
               System.out.println("inside Err");
               try {
                    int c;
                    while ((c = is.read()) != -1) {
                         os.write(c);
                         os.flush();
               } catch (IOException e) {
               System.out.println("End of Run Method..Err");
}

Answer 1

Console input is line buffered. This means you only get the first character a line after the newline has been inputed.
The same thing happen if you just type on the console.
I am not aware of any simple way around this.
IDEs get around this by changing the application run so that the input/output is captured as it happens and sent over a socket connection.