Java 计算用户百分比并保留两位小数

import\ java.math.BigDecimal;\nfinal\ Long\ numberOfUsers\ =\ fromLaunchToSpecifiedMonth.get(companyEnumValue);\nfinal\ Integer\ totalUserNumber\ =\ comMap.get(companyEnumValue);\nBigDecimal\ percentage\ =\ BigDecimal.valueOf((double)numberOfUsers\ /\ totalUserNumber\ *\ 100);\npercentage\ =\ percentage.setScale(2,\ BigDecimal.ROUND_HALF_UP);\nSystem.out.println(percentage\ +\ "%");