question: public PidFile ( final File directory , final String filename ) throws FileNotFoundException { if ( ! directory . isDirectory ( ) && directory . exists ( ) ) { throw new IllegalArgumentException ( "Argument '" + directory + "' must be an existing directory!" ) ; } final File file = new File ( directory , filename ) ; if ( ! file . exists ( ) || file . isDirectory ( ) ) { throw new FileNotFoundException ( "Unable to find PID file '" + filename + "' in directory " + directory ) ; } this . pidFile = file ; }
target:  Constructs a PidFile for reading pid stored in a file.