/**     * 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    }