java 今天、明天、后天、明年今天，昨天、前天、过去七天、过去一年日期的整体封装；

 
    public  static Map  timesArea(){
        Integer arr[] = {-1,-2,-3,-4,-5,-6,-29,-365,0,1,2,3,4,5,6,7,30,365};
        HashMap  map=new HashMap<>();
        for (int i = 0; i < arr.length; i++) {
            Calendar calendar = Calendar.getInstance();
            //如果是 + x 代表获取的是未来的日期,相反之 - x 则是获取过去的日期
            calendar.set(Calendar.DAY_OF_YEAR, calendar.get(Calendar.DAY_OF_YEAR) + arr[i]);
            Date date = calendar.getTime();
            
            SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");//此处可以自定义格式
            
            String today = format.format(date)+" 00:00:00";//此处00：00：00可以去掉
            String keyName="date"+arr[i].toString();
            
            map.put(keyName,today);
            System.out.println(keyName);
            System.out.println(today);

        }
        return map;

    }