when i start process like process= Runtime.getRuntime().exec("gnome-terminal");, it start shell execution, i want to stop shell execution and want to redirect I/O from process, can anybody tell how i can do this?

my code is:

public void start_process()
{
     try
     {
         process= Runtime.getRuntime().exec("bash");
         pw= new PrintWriter(process.getOutputStream(),true);
         br=new BufferedReader(new InputStreamReader(process.getInputStream()));
         err=new BufferedReader(new InputStreamReader(process.getErrorStream()));

     }
     catch (Exception ioe)
     {
         System.out.println("IO Exception-> " + ioe);
     }


}

public void execution_command()
{

    if(check==2)
    {
        try
        {
            boolean flag=thread.isAlive();
            if(flag==true)
                thread.stop();

            Thread.sleep(30);
            thread = new MyReader(br,tbOutput,err,check);
            thread.start();

        }catch(Exception ex){
            JOptionPane.showMessageDialog(null, ex.getMessage()+"1");
        }
    }
    else
    {
        try
        {
            Thread.sleep(30);
            thread = new MyReader(br,tbOutput,err,check);
            thread.start();
            check=2;

        }catch(Exception ex){
            JOptionPane.showMessageDialog(null, ex.getMessage()+"1");
        }

    }
}

private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {                                         
    // TODO add your handling code here:
    command=tfCmd.getText().toString().trim();

    pw.println(command);

    execution_command();

}    

when i enter some command in textfield and press execute button, nothing displayed on my output textarea, how i can stop shellexecution and can redirect Input and output?