How can I call external exe in java

Question

Hi ,
Is It Possible to call external exe in java.
I read Runtime.exe("some exe") but actually my exe expects some input to process for that how can i pass the input to my exe and how can get the response from exe to my java class.
any sample code is welcome.
Thanks
Babu H

Answer 1

example
import javax.swing.*;
import java.awt.*;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.io.*;
public class RuntimeExample extends JFrame {
    private JTextArea textArea;
    private JTextField textField;
    private PrintWriter writer;
    public RuntimeExample()
        init();
        initProcess();
    public void init()
        textArea = new JTextArea(20, 80);
        textArea.setEditable(false);
        textField = new JTextField(30);
        textField.addKeyListener(new KeyAdapter()
            public void keyPressed(KeyEvent event) {
                if (event.getKeyCode() == KeyEvent.VK_ENTER)
                    if (writer != null)
                        textArea.setText("");
                        writer.print(textField.getText() + "\r\n");
                        writer.flush();
                        textField.setText("");
        Container container = getContentPane();
        JScrollPane scrollPane = new JScrollPane();
        scrollPane.setViewportView(textArea);
        container.add(scrollPane, BorderLayout.CENTER);
        container.add(textField, BorderLayout.SOUTH);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        pack();
        textField.grabFocus();
        setVisible(true);
    public static void main(String[] args) {
        new RuntimeExample();
    public void initProcess()
        Runtime rt = Runtime.getRuntime();
        try
            //Process p = rt.exec(new String [] {"cmd", "/C", textField.getText()});
            //textArea.setText("");
            //textField.setText("");
            Process p = rt.exec("cmd");
            writer = new PrintWriter(p.getOutputStream());
            Thread thread1 = new Thread(new StreamReader(p.getErrorStream()));
            Thread thread2 = new Thread(new StreamReader(p.getInputStream()));
            thread1.start();
            thread2.start();
            System.out.println("Exit Value = " + p.waitFor());
        catch (Exception ex)
            textArea.append(ex.getMessage());
            ex.printStackTrace();
    public class StreamReader implements Runnable
        InputStream is;
        public StreamReader(InputStream is)
            this.is = is;
        public void run()
            try
                BufferedReader reader = new BufferedReader(new InputStreamReader(is));
                String data;
                while ((data = reader.readLine()) != null)
                    textArea.append(data + "\n");
                reader.close();
            catch (IOException ioEx)
                ioEx.printStackTrace();
}you can pass input to the exe by using getOutputStream() from Process and get the output from getInputStream() from Process