BigDecimal decimal = new BigDecimal("6.544355");
decimal = decimal.setScale(1,BigDecimal.ROUND_HALF_UP);//四舍五入
//jdk8 时间类 Localtime LocalDate LocalDateTime DateTimeFormatter
LocalDate now = LocalDate.now();
LocalTime time = LocalTime.now();
System.out.println(time);
System.out.println(now);
LocalDateTime dateTime = LocalDateTime.now();
System.out.println(dateTime);
DateTimeFormatter pattern = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm");
String format = dateTime.format(pattern);
System.out.println(format);