時間簡單操作

java中時間計算

時間轉換

    public static void main(String[] args) throws ParseException {
        SimpleDateFormat sf=new SimpleDateFormat("yyyy/MM/dd HH:mm:SS");
        String format = sf.format(new Date());
        System.out.println(format);
        Date parse = sf.parse(format);
        System.out.println(parse);
    }

執行結果

2020/06/10 10:23:846
Wed Jun 10 10:23:00 CST 2020

比較兩個hh:mm:ss值的大小

    public static boolean checkHHMMSSEquals(String startStr, String endStr) {
        if (StringUtils.isEmpty(startStr) || StringUtils.isEmpty(endStr)) {
            return false;
        }
        String[] array1 = startStr.split(":");//分割時間格式時:分:秒
        String[] array2 = endStr.split(":");
        int total1 = Integer.valueOf(array1[0]) * 3600 + Integer.valueOf(array1[1]) * 60 + Integer.valueOf(array1[2]);
        int total2 = Integer.valueOf(array2[0]) * 3600 + Integer.valueOf(array2[1]) * 60 + Integer.valueOf(array2[2]);
        return total1 >= total2;
    }

簡單執行

    public static void main(String[] args) {
        boolean b = checkHHMMSSEquals("18:33:11", "19:22:44");
        System.out.println(b);
    }

執行結果

false

計算兩個時間差

    private static void TimeDifference2() throws ParseException {
        SimpleDateFormat simpleFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
        long from = simpleFormat.parse("2020/05/26 12:00:00").getTime();
        long to = simpleFormat.parse("2020/05/26 14:30:00").getTime();
        float minutes = (float) ((to - from)/(1000 * 60));
        float i =(float) Math.round((minutes / 60) * 100) / 100;
        System.out.println(minutes);
        System.out.println(i);
    }

計算結果

150.0
2.5

選出幾段時間中的最大最小值

String類型的

    public static List<String> sortListDesc(List<String> list) throws ParseException{
        List<String> retStr=new ArrayList<String>();
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Map<Long,String> map = new TreeMap<Long,String>();
        for(int i=0;i<list.size();i++){
            String dateStr = list.get(i);
            map.put(sdf.parse(dateStr).getTime(), dateStr);
        }
        Collection<String> coll=map.values();
        retStr.addAll(coll);
        Collections.reverse(retStr);
        return retStr;
    }

Date類型的

    public static List<Date> sortList(List<String> list) throws ParseException{
        List<Date> retStr=new ArrayList<Date>();
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        Map<Long,String> map = new TreeMap<Long,String>();
        for(int i=0;i<list.size();i++){
            retStr.add(sdf.parse(list.get(i)));
        }
        Collections.sort(retStr);
        Collections.reverse(retStr);
        return retStr;
    }

簡單運行

    public static void main(String[] args) throws ParseException {
        // TODO Auto-generated method stub
        List<String> list =new ArrayList<String>();
        list.add("2014-09-04 10:34:41");
        list.add("2013-08-04 13:42:19");
        list.add("2014-09-04 16:46:49");
        list.add("2010-01-04 12:32:00");
        list.add("2004-04-04 10:34:41");
        list.add("2009-05-14  23:42:19");
        list.add("2014-12-04  06:08:49");
        list.add("2010-01-24  01:32:00");

        List<String> descList=sortListDesc(list);
        System.out.println("最近的時間爲："+descList.get(0));
        System.out.println("最遠的時間爲："+descList.get(descList.size()-1));

        List<Date> dateList=sortList(list);
        System.out.println("最近的時間爲："+dateList.get(0));
        System.out.println("最遠的時間爲："+dateList.get(dateList.size()-1));

    }

執行結果

最近的時間爲：2014-12-04  06:08:49
最遠的時間爲：2004-04-04 10:34:41
最近的時間爲：Thu Dec 04 06:08:49 CST 2014
最遠的時間爲：Sun Apr 04 10:34:41 CST 2004