/**
* 解决精度的问题
*/
@Test
void testBigDecimal() {
/**
* no problem
*/
System.out.println(new BigDecimal("1225.12").setScale(2));
System.out.println(new BigDecimal("1225.1").setScale(2));
System.out.println(new BigDecimal("1225").setScale(2));
/**
* has problem
*/
System.out.println(new BigDecimal("1225.120").setScale(2)); // ok
/**
* error : java.lang.ArithmeticException: Rounding necessary
* solution : 设置舍入模式, 使用 setScale(int newScale, RoundingMode roundingMode); 方法
*/
System.out.println(new BigDecimal("1225.121").setScale(2)); // error
System.out.println(new BigDecimal("1225.121").setScale(2, BigDecimal.ROUND_HALF_UP)); // right
System.out.println(new BigDecimal("1225.121").setScale(2, RoundingMode.HALF_UP)); // right
}