时间相关几个需求

1、获取据现在n月前或n月后的年份、月初、月末

 public static int getMonth(int offset) {        Calendar cal = Calendar.getInstance();        cal.setTime(new Date());        cal.set(Calendar.MONTH, cal.get(Calendar.MONTH) + offset);        return cal.get(Calendar.MONTH) + 1;//获取月份           }    return cal.get(Calendar.YEAR);//获取年份    return cal.getActualMaximum(Calendar.DAY_OF_MONTH);//获取月末

2、sqlite数据库里根据日期查询

SELECT * ID from yd_FeeDetailed where datetime(SysTime) between datetime(‘2017-04-01 00:00:00’) and datetime(‘2017-04-30 23:59:59’);