BigDecimal取整
Java中BigDecimal取整方法BigDecimal bd = new BigDecimal("12.1");long l = bd.setScale( 0, BigDecimal.ROUND_UP ).longValue(); // 向上取整long l = bd.setScale( 0, BigDecimal.ROUND_DOWN ).longValue(); // 向下取整* 对于正数而言，ROUND_UP = ROUND_CEILING，ROUND_DOW
