BigDecimal.setScale()方法实用技巧

import java.math.BigDecimal;
/** * @author yanghao * @version SetScale.java, v 0.1 2019-12-24 19:56 */
public class SetScale { 

public static void main(String[] args){ 

BigDecimal money = new BigDecimal("2.35");
//格式化小数点
System.out.println("scale == " + money.scale());
//直接删除多余的小数位，如2.35会变成2.3
System.out.println("ROUND_DOWN == " + money.setScale(1, BigDecimal.ROUND_DOWN));
//进位处理（无论小数如何），2.35变成2.4
System.out.println("ROUND_UP == " + money.setScale(1, BigDecimal.ROUND_UP));
//四舍五入，2.35变成2.4（目前最常用的金额处理方法）
System.out.println("ROUND_HALF_UP == " + money.setScale(1, BigDecimal.ROUND_HALF_UP));
//四舍五入，2.35变成2.3，如果是5则向下舍（6及以上则向上入）
System.out.println("ROUND_HALF_DOWN == " + money.setScale(1, BigDecimal.ROUND_HALF_DOWN));
}
}

scale == 2
ROUND_DOWN == 2.3
ROUND_UP == 2.4
ROUND_HALF_UP == 2.4
ROUND_HALF_DOWN == 2.3