ScriptExecutor.java

import org.apache.log4j.Logger;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Arrays;

/**
 * Created by thangpn7 on 12/15/2017
 */
public class ScriptExecutor {
    private Logger logger = Logger.getLogger(ScriptExecutor.class);
    private PrintWriter writer;

    public ScriptExecutor() throws IOException {
        Process process = Runtime.getRuntime().exec("cmd");
        OutputStream pStdin = process.getOutputStream(); // <- Eh? write to this
        redirectProcessOutputs(process);
        writer = new PrintWriter(pStdin);
    }

    private void redirectProcessOutputs(Process process) {
        InputStream pStdout = process.getInputStream();
        InputStream pStderr = process.getErrorStream();

        Thread errorPipe = new Thread(new SyncPipe(pStderr, System.err));
        errorPipe.start();
        Thread outputPipe = new Thread(new SyncPipe(pStdout, System.out));
        outputPipe.start();
    }

    public void executeCmd(String... commands) throws IOException {
        logger.debug("Executing " + Arrays.toString(commands));
        for (String cmd : commands) {
            writer.println(cmd);
            writer.flush();
        }
    }

    public void close() throws IOException {
        writer.println("exit");
        writer.flush();
    }
}

SyncPipe.java

import java.io.InputStream;
import java.io.OutputStream;

/**
 * Created by thangpn7 on 12/15/2017
 */
public class SyncPipe implements Runnable {
    private final OutputStream out;
    private final InputStream in;

    public SyncPipe(InputStream in, OutputStream out) {
        this.in = in;
        this.out = out;
    }

    @Override
    public void run() {
        try {
            final byte[] buffer = new byte[1024];

            int length;
            while ((length = in.read(buffer)) != -1) {
                out.write(buffer, 0, length);
            }

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}