question: private int readEpoch ( File epochFile ) { int epoch = - 1 ; if ( ! epochFile . exists ( ) ) { return epoch ; } try { Scanner scanner = new Scanner ( epochFile ) ; epoch = scanner . nextInt ( ) ; log . debug ( "Got epoch {} from file {}" , epoch , epochFile . getName ( ) ) ; } catch ( IOException e ) { log . error ( "read epoch from file({}) failed. e=" , epochFile . getName ( ) , e ) ; } return epoch ; }
target:  Read epoch from epoch file