org.linkedin.util-core/src/main/java/org/linkedin/util/concurrent/ExternalCommand.java
public void start() throws IOException
  {
    _process = _processBuilder.start();
    _out = new InputReader(new BufferedInputStream(_process.getInputStream()));
    _err = new InputReader(new BufferedInputStream(_process.getErrorStream()));

    _out.start();
    _err.start();
  }
public void start() throws IOException
  {
    _process = _processBuilder.start();
    _out = new InputReader(new BufferedInputStream(_process.getInputStream()));
    _err = new InputReader(new BufferedInputStream(_process.getErrorStream()));

    _out.start();
    _err.start();
  }
After creating the command, you have to start it...

@throws IOException