public static void main(String[] args) {
        String s = "-北京 2.4 1.3 12.34534 0.123 -上海 3.1 0 0 12.345 2.1";
        Pattern p = Pattern.compile("(\\s\\d+(\\.\\d+)?){4}");
        Matcher m = p.matcher(s);
        while(m.find())
        {
            int start = m.start();
            int end = m.end();
            System.out.println(s.substring(start-2,start));
            String[] strs = s.substring(start, end).trim().split("\\s");
            for(String s1:strs)
            {
                System.out.println(s1);
            }
        }
    }