思路：
先获得当前季度的开始和结束日期，在当前日期的基础上往前推3个月即上个季度的开始和结束日期
/*** @param flag true：开始日期；false：结束日期* @return*/public static String getLastQuarterTime(boolean flag){SimpleDateFormat shortSdf = new SimpleDateFormat("yyyy-MM-dd");SimpleDateFormat longSdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");String resultDate="";Date now = null;try {Calendar calendar = Calendar.getInstance();int currentMonth = calendar.get(Calendar.MONTH) + 1;//true：开始日期；false：结束日期if(flag){if (currentMonth >= 1 && currentMonth <= 3)calendar.set(Calendar.MONTH, 0);else if (currentMonth >= 4 && currentMonth <= 6)calendar.set(Calendar.MONTH, 3);else if (currentMonth >= 7 && currentMonth <= 9)calendar.set(Calendar.MONTH, 6);else if (currentMonth >= 10 && currentMonth <= 12)calendar.set(Calendar.MONTH, 9);calendar.set(Calendar.DATE, 1);now = longSdf.parse(shortSdf.format(calendar.getTime()) + " 00:00:00");}else{if (currentMonth >= 1 && currentMonth <= 3) {calendar.set(Calendar.MONTH, 2);calendar.set(Calendar.DATE, 31);} else if (currentMonth >= 4 && currentMonth <= 6) {calendar.set(Calendar.MONTH, 5);calendar.set(Calendar.DATE, 30);} else if (currentMonth >= 7 && currentMonth <= 9) {calendar.set(Calendar.MONTH, 8);calendar.set(Calendar.DATE, 30);} else if (currentMonth >= 10 && currentMonth <= 12) {calendar.set(Calendar.MONTH, 11);calendar.set(Calendar.DATE, 31);}now = longSdf.parse(shortSdf.format(calendar.getTime()) + " 23:59:59");}calendar.setTime(now);// 设置日期calendar.add(Calendar.MONTH, -3);resultDate = longSdf.format(calendar.getTime());} catch (Exception e) {;}return resultDate;}
