Cannot read the output from windows command.

Question

Hello
I have the following classes
package cmd;
import java.io.IOException;
public class CMD {
    public CMD(){
        ProcessBuilder pb = new ProcessBuilder()
        .command("cmd.exe","/c","del *.*")
        .redirectErrorStream(false);
        Process p;
        try {
            p = pb.start();
            StreamGobbler errorGobbler = new StreamGobbler(p.getErrorStream(), "ERROR");
            // any output?
            StreamGobbler outputGobbler = new StreamGobbler(p.getInputStream(), "OUTPUT");
            // start gobblers
            outputGobbler.start();
            errorGobbler.start();
        } catch (IOException e) {
            // TODO Auto-generated catch block
        System.out.println("eee "+e.getMessage());;
    public static void main(String[] args) {
        System.out.println("x");
        new CMD();
        System.out.println("x");
and
package cmd;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
public class StreamGobbler extends Thread {
    InputStream is;
    String type;
    StreamGobbler(InputStream is, String type) {
        this.is = is;
        this.type = type;
    @Override
    public void run() {
        try {
            InputStreamReader isr = new InputStreamReader(is);
            BufferedReader br = new BufferedReader(isr);
            String line = null;
            while ((line = br.readLine()) != null)
                System.out.println(type + "> " + line);
        catch (IOException ioe) {
            ioe.printStackTrace();
Please note that I cannot seee the output from wndows command : del *.* and the java class execution does not finished.
I I will replace the above command with the dir command then the output of the command is visible.
Would you give me a hint about how to modify the above clases in order to parse the output of the del *.* ?
Please note that the above example is important because I am developping a tool and it is mandatory for that tool to parse the output from a windows batch command.
Best regards,

Answer 1

Please note that I cannot seee the output from wndows command : del *.* and the java class execution does not finished.
I I will replace the above command with the dir command then the output of the command is visible.
Would you give me a hint about how to modify the above clases in order to parse the output of the del *.* ?
No - but I will give you a hint about ProcessBuilder and how to develop software properly.
Hint #1: Don't try to automate something that you don't know, or understand, how to do manually.
a. Do you know how to execute 'del *.*' manually in a command window?
b. Did you try that manually to see what happens?
My guess is 'no'. If you had you would know that the response to a 'del *.*' command is going to be this:
Are you sure (Y/N)?
And your 'java class execution' doesn't finish because the 'del' command is waiting for you to answer that question.
Hint #2: Don't try to use ProcessBuilder for an application that requires console input unless you first know how to provide that console input via your Java code.
Your code will wait forever since it does NOT answer that question.
Search the net and The Java Tutorials and  you can find examples of executing command line utilities. Then try those examples first and make sure that:
1. They work for you
2. You understand HOW they work
Then you can modify those examples to do what you want to do.