从文本文件中获取格式化数字的简单方法？

ifstream file(\"data/maps/ssdebug1.cfg\");
    string line;
float startx = 0;
    sscanf (line.c_str(), \"start-x = %f;\", &startx);

FileInputStream fis = new FileInputStream(\"data/maps/ssdebug1.cfg\");
Properties prop = new Properties();
prop.load(fis);
fis.close();

// you can have any number of properties with comments. 
// However, it is not assumed aline ends with a \';\'
String start_x = prop.getProperty(\"start-x\");
double startx = Double.parseDouble(start_x);

 Scanner in = new Scanner(new File(\"data/maps/ssdebug1.cfg\"));
      while (in.hasNextLong()) {
          long my = in.nextLong();
      }