转载地址:http://blog.csdn.net/jobjava/article/details/6764623
金额的数据类型是BigDecimal
通过BigDecimal的divide方法进行除法时当不整除,出现无限循环小数时,就会抛异常的,异常如下:Java.lang.ArithmeticException:
Non-terminating decimal expansion; no exact representable decimal result. at java.math.BigDecimal.divide(Unknown Source)
应用场景:一批*客户的单价是1000元/年,如果按月计算的话1000/12=83.3333333333....
解决之道:就是给divide设置精确的小数点divide(xxxxx,2, BigDecimal.ROUND_HALF_EVEN)
在 java中, 四舍五入通过 BigDecimal 来实现。一定要注意:BigDecimal is Immutable。
也就是跟String一样,对前一个的修改,比如setScale(), add()等都会返回一个新的BigDecimal.
四舍五入舍入模式是 BigDecimal.ROUND_HALF_UP
BigDecimal定义了一下舍入模式,只有在作除法运算或四舍五入时才用到舍入模式,
下面简单介绍,详细请查阅J2se API文档
static int |
Rounding mode to round towards zero. 向零方向舍入 |
static int |
Rounding mode to round towards negative infinity. 向负无穷方向舍入 |
static int |
Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round down. 向(距离)最近的一边舍入,除非两边(的距离)是相等,如果是这样,向下舍入,例如1.55保留一位 小数结果为1.5 |
static int |
Rounding mode to round towards the "nearest neighbor" unless both neighbors are equidistant, in which case, round towards the even neighbor. 向(距离)最近的一边舍入,除非两边(的距离)是相等,如果是这样,如果保留位数是奇数, 使用ROUND_HALF_UP,如果是偶数,使用ROUND_HALF_DOWN |
static int |
Rounding mode to round towards "nearest neighbor" unless both neighbors are equidistant, in which case round up. 向(距离)最近的一边舍入,除非两边(的距离)是相等,如果是这样,向上舍入, 1.55保留一位 小数结果为1.6 |
static int |
Rounding mode to assert that the requested operation has an exact result, hence no rounding is necessary. 计算结果是精确的,不需要舍入模式 |
static int |
Rounding mode to round away from zero. 向远离0的方向舍入 |