protected int _countPeriods(String str)
    {
        int commas = 0;
        for (int i = 0, end = str.length(); i < end; ++i) {
            int ch = str.charAt(i);
            if (ch < '0' || ch > '9') {
                if (ch == '.') {
                    ++commas;
                } else {
                    return -1;
                }
            }
        }
        return commas;
    }
protected int _countPeriods ( String str ) { int commas = 0 ; for ( int i = 0 , end = str . length ( ) ; i < end ; ++ i ) { int ch = str . charAt ( i ) ; if ( ch < '0' || ch > '9' ) { if ( ch == '.' ) { ++ commas ; } else { return - 1 ; } } } return commas ; }
Helper method to find Strings of form "all digits" and "digits-comma-digits"