String settings = "# test" + "/n" + "cource=java" + "/n" + "last_open_date = 2020-06-14";      
   ByteArrayInputStream input = new ByteArrayInputStream(settings.getBytes("UTF-8"));       
   Properties props = new Properties();        
  props.load(input);        
  System.out.println("course: " + props.getProperty("course"));        
  System.out.println("last_open_date: " + props.getProperty("last_open_date"));      
  System.out.println("last_open_file: " + props.getProperty("last_open_file"));        
  System.out.println("auto_save: " + props.getProperty("auto_save", "60"));

我这样写的，为啥cource和last_open_date 打印出来都是null呢？