question: public static long parseCommitCounterFile ( final String name , final String ext ) throws NumberFormatException { if ( name == null ) throw new IllegalArgumentException ( ) ; if ( ext == null ) throw new IllegalArgumentException ( ) ; final int len = name . length ( ) - ext . length ( ) ; final String fileBaseName = name . substring ( 0 , len ) ; final long commitCounter = Long . parseLong ( fileBaseName ) ; return commitCounter ; }
target:  Parse out the commitCounter from the file name.