使用Calendar类可以很方便的定位到历史或将来的某个日期:
简单演示如下:
String startDate = "";
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Calendar calendar = Calendar.getInstance();
//在当月的基础上向前推2月
calendar.add(Calendar.MONTH, -2);
//设置日为对应月份的第3天
calendar.set(Calendar.DAY_OF_MONTH, 3);
startDate = sdf.format((calendar.getTime()));
System.out.println("startDate="+startDate); //return "2015-02-03"
System.out.println("today="+sdf.format(new Date())); //return "2015-04-01"