判断日期是否在7天之内

public boolean isLatestWeek(Date addtime,Date now){  
    Calendar calendar = Calendar.getInstance();  //得到日历  
    calendar.setTime(now);//把当前时间赋给日历  
    calendar.add(Calendar.DAY_OF_MONTH, -7);  //设置为7天前  
    Date before7days = calendar.getTime();   //得到7天前的时间  
    if(before7days.getTime() < addtime.getTime()){  
        return true;  
    }else{  
        return false;  
    }  
}