public boolean isTime(String wfsj) throws ParseException {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Date today = sdf.parse(wfsj);
        SimpleDateFormat df = new SimpleDateFormat("HH:mm:ss");//设置日期格式

        Date nowTime =df.parse(df.format(today));
        //上午的规定时间
        Date amBeginTime = df.parse("00:00:00");
        Date amEndTime = df.parse("07:00:00");
        //下午的规定时间
        Date pmBeginTime = df.parse("21:00:00");
        Date pmEndTime = df.parse("23:59:59");

        //调用判断方法是否在规定时间段内
        boolean isTime = timeCalendar(nowTime, amBeginTime, amEndTime,pmBeginTime,pmEndTime);

        if(isTime){
            //处于规定的时间段内
            System.out.println(isTime);
        }else{
            //不处于规定的时间段内
            System.out.println(isTime);
        }
        return isTime;
    }

public static boolean timeCalendar(Date nowTime, Date amBeginTime, Date amEndTime, Date pmBeginTime, Date pmEndTime) {
//设置当前时间
Calendar date = Calendar.getInstance();
date.setTime(nowTime);
//设置开始时间
Calendar amBegin = Calendar.getInstance();
amBegin.setTime(amBeginTime);//上午开始时间
Calendar pmBegin = Calendar.getInstance();
pmBegin.setTime(pmBeginTime);//下午开始时间
//设置结束时间
Calendar amEnd = Calendar.getInstance();
amEnd.setTime(amEndTime);//上午结束时间
Calendar pmEnd = Calendar.getInstance();
pmEnd.setTime(pmEndTime);//下午结束时间
//处于开始时间之后,和结束时间之前的判断
if ((date.after(amBegin) && date.before(amEnd)) || (date.after(pmBegin) && date.before(pmEnd))) {
return true;
} else {
return false;
}
}