bigdecimal保留两位小数

超、凢脫俗 2023-10-05 21:26 25阅读 0赞

**bigdecimal保留两位小数**

public class test1_format {
    public static void main(String[] args) {
    BigDecimal decimal = new BigDecimal("1.12345");
    System.out.println(decimal);
    BigDecimal setScale = decimal.setScale(4,BigDecimal.ROUND_HALF_DOWN);
    System.out.println(setScale);
    
    BigDecimal setScale1 = decimal.setScale(4,BigDecimal.ROUND_HALF_UP);
    System.out.println(setScale1);
    }
    }

参数定义

**ROUND\_CEILING**  
Rounding mode to round towards positive infinity.  
向正无穷方向舍入

**ROUND\_DOWN**  
Rounding mode to round towards zero.  
向零方向舍入

**ROUND\_FLOOR**  
Rounding mode to round towards negative infinity.  
向负无穷方向舍入

**ROUND\_HALF\_DOWN**  
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

**ROUND\_HALF\_EVEN**  
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

**ROUND\_HALF\_UP**  
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

**ROUND\_UNNECESSARY**  
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

**ROUND\_UP**  
Rounding mode to round away from zero.  
向远离0的方向舍入