question: public static long hexStringToLong ( final String hexString ) { Preconditions . checkNotNull ( hexString , "Error: Unicode string can't be null" ) ; Preconditions . checkArgument ( isHexString ( hexString ) , String . format ( "Error: Hex string '%s' is not a vaild hex string" , hexString ) ) ; if ( ( hexString . length ( ) == 16 ) && ( hexString . charAt ( 0 ) >= 8 ) ) { final String strAddr1 = hexString . substring ( 0 , hexString . length ( ) - 8 ) ; final String strAddr2 = hexString . substring ( hexString . length ( ) - 8 ) ; return ( Long . parseLong ( strAddr1 , 16 ) << 32 ) + Long . parseLong ( strAddr2 , 16 ) ; } return Long . parseLong ( hexString , 16 ) ; }
target:  Converts an hex string to long.