public void writeString(String s2) throws IOException {
  String s=s2;
  if (s == null) {
    s="";
  }
  writeString(s.getBytes());
}

public void writeString ( String s2 ) throws IOException { String s = s2 ; if ( s == null ) { s = "" ; } writeString ( s . getBytes ( ) ) ; }
write a string to the output stream using the default encoding and add terminating null
