java之 LocalDate、LocalTime、LocalDateTime实践

深碍√TFBOYSˉ_ 2022-12-26 09:25 118阅读 0赞

## LocalDate、LocalTime、LocalDateTime是Java8提供的全新时间类 ##

示例代码：

System.out.println("------------使用LocalDate-------------");
            //获取当前年月日
            LocalDate localDate = LocalDate.now();
            System.out.println("当前的年月日:"+localDate);
            //构造指定的年月日
            LocalDate localDate1 = LocalDate.of(2020, 12, 1);
            System.out.println("指定的年月日:"+localDate1);
            //获取单独的年月日
            int year = localDate.getYear();
            int year1 = localDate.get(ChronoField.YEAR);
            System.out.println("当前年:"+year);
            System.out.println("当前年:"+year1);
            //月
            Month month = localDate.getMonth();
            int month1 = localDate.get(ChronoField.MONTH_OF_YEAR);
            System.out.println("当前月:"+month);
            System.out.println("当前月:"+month1);
            int day = localDate.getDayOfMonth();
            //日
            int day1 = localDate.get(ChronoField.DAY_OF_MONTH);
            System.out.println("当前天:"+day);
            System.out.println("当前天:"+day1);
            //周
            DayOfWeek dayOfWeek = localDate.getDayOfWeek();
            int dayOfWeek1 = localDate.get(ChronoField.DAY_OF_WEEK);
            System.out.println("当前星期:"+dayOfWeek);
            System.out.println("当前星期:"+dayOfWeek1);
    // ------------使用LocalDate-------------
    // 当前的年月日:2020-12-04
    // 指定的年月日:2020-12-01
    // 当前年:2020
    // 当前年:2020
    // 当前月:DECEMBER
    // 当前月:12
    // 当前天:4
    // 当前天:4
    // 当前星期:FRIDAY
    // 当前星期:5
    
            System.out.println("------------使用LocalTime-------------");
            //构造时间
            LocalTime localTime = LocalTime.of(13, 51, 10);
            //当前时间
            LocalTime localTime1 = LocalTime.now();
            System.out.println("构造时间："+localTime);
            System.out.println("当前时间："+localTime1);
            //获取时分秒
            //获取小时
            int hour = localTime.getHour();
            int hour1 = localTime.get(ChronoField.HOUR_OF_DAY);
            System.out.println("当前小时："+hour);
            System.out.println("ChronoField.HOUR_OF_DAY："+hour1);
            //获取分
            int minute = localTime.getMinute();
            int minute1 = localTime.get(ChronoField.MINUTE_OF_HOUR);
            System.out.println("当前分钟："+minute);
            System.out.println("ChronoField.MINUTE_OF_HOUR："+minute1);
            //获取秒
            int second = localTime.getMinute();
            int second1 = localTime.get(ChronoField.SECOND_OF_MINUTE);
            System.out.println("当前秒："+second);
            System.out.println("ChronoField.SECOND_OF_MINUTE："+second1);
    // ------------使用LocalTime-------------
    // 构造时间：13:51:10
    // 当前时间：11:50:10.294
    // 当前小时：13
    // ChronoField.HOUR_OF_DAY：13
    // 当前分钟：51
    // ChronoField.MINUTE_OF_HOUR：51
    // 当前秒：51
    // ChronoField.SECOND_OF_MINUTE：10
    
            System.out.println("------------使用LocalDateTime-------------");
            //当前时间
            LocalDateTime localDateTime = LocalDateTime.now();
            //构造时间
            LocalDateTime localDateTime1 = LocalDateTime.of(2020, Month.DECEMBER, 1, 13, 58, 56);
            System.out.println("现在时间：LocalDateTime.now(): "+ localDateTime);
            System.out.println("构造时间：LocalDateTime.of: "+ localDateTime1);
    
            System.out.println("时间拼接 LocalDateTime = LocalDate + LocalTime");
            LocalDateTime localDateTime2 = LocalDateTime.of(localDate, localTime);
            LocalDateTime localDateTime3 = localDate.atTime(localTime);
            LocalDateTime localDateTime4 = localTime.atDate(localDate);
            System.out.println("LocalDateTime.of: "+ localDateTime2);
            System.out.println("localDate.atTime: "+ localDateTime3);
            System.out.println("localTime.atDate: "+ localDateTime4);
    // ------------使用LocalDateTime-------------
    // 现在时间：LocalDateTime.now(): 2020-12-04T11:50:10.295
    // 构造时间：LocalDateTime.of: 2020-12-01T13:58:56
    // 时间拼接 LocalDateTime = LocalDate + LocalTime
    // LocalDateTime.of: 2020-12-04T13:51:10
    // localDate.atTime: 2020-12-04T13:51:10
    // localTime.atDate: 2020-12-04T13:51:10
    
    
            System.out.println("----------------使用线程安全的DateTimeFormatter格式化---------------");
            //日期格式化，多线程安全
            DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy-mm-dd hh:MM:ss");
            System.out.println("DateTimeFormatter格式化：" + dateTimeFormatter.format(localDateTime));
    // ----------------使用线程安全的DateTimeFormatter格式化---------------
    // DateTimeFormatter格式化：2020-50-04 11:12:10

格式化建议使用DateTimeFormatter，线程安全的。

本文参考：  
[https://www.cnblogs.com/pengthrree/p/12185996.html][https_www.cnblogs.com_pengthrree_p_12185996.html]

[https_www.cnblogs.com_pengthrree_p_12185996.html]: https://www.cnblogs.com/pengthrree/p/12185996.html