Java example:

Demo.java

package expr;

import java.io.InputStream;

import static java.lang.System.in;
import static java.lang.System.out;

class Gopher implements Runnable {
  public void run() {
    try {
      out.println( "  Gopher started" );
      out.println("Type something:");
      int charInt = 0;
      while (charInt != -1) {
        charInt = in.read();
        String charStr = Character.toString( charInt );
        out.println( "Gopher int=" + charInt + "  str=" + charStr );
      }
    } catch (Exception ex) {
      out.println( "  Gopher caught:"+ ex );
    } finally {
      out.println( "  Gopher finished" );
    }
  }
}

public class Demo {
  public static void main(String[] args) {
    try {
      out.println( "Hello ProcessBuilder!" );
      out.println( "Starting Gopher... " );
      Thread th = new Thread( new Gopher() );
      th.setDaemon( false );
      th.start();
      out.println( "                    done!   daemon?  " + th.isDaemon() );

      if (false) {
        out.println( "main sleeping..." );
        Thread.sleep( 10 * 1000 );
        out.println( "main leaving" );
      }

      ProcessBuilder pb = new ProcessBuilder( "/bin/bash", "-c", "echo yolo" );
      Process proc = pb.start();
      InputStream istream = proc.getInputStream();
      byte[] bytes = istream.readAllBytes();
      String result = new String( bytes );
      out.println( "proc result='" + result + "'" );

      if (true) {
        out.println( "main sleeping..." );
        Thread.sleep( 10 * 1000 );
        out.println( "main leaving" );
      }

      // assert proc.getInputStream().read() == -1;
    } catch (Exception ex) {
    }
  }
}

contents of ./go.bash
----------------------------------
#!/bin/bash
rm src/expr/*.class
javac src/expr/*.java
ls -ldF src/expr/*.class
java -cp src expr.Demo