public boolean mkdir(){
  SecurityManager security=System.getSecurityManager();
  if (security != null) {
    security.checkWrite(path);
  }
  if (isInvalid()) {
    return false;
  }
  return fs.createDirectory(this);
}

public boolean mkdir ( ) { SecurityManager security = System . getSecurityManager ( ) ; if ( security != null ) { security . checkWrite ( path ) ; } if ( isInvalid ( ) ) { return false ; } return fs . createDirectory ( this ) ; }
creates the directory named by this abstract pathname .
