Java8生成时间方式及格式化时间的方法实例

    LocalDate date = LocalDate.now();
    System.out.println(date);
    
结果：2020-08-20

    LocalDate date = LocalDate.now();
    date = LocalDate.of(2020, 9, 20);
    System.out.println(date);
    
结果：2020-09-20

     LocalDate date = LocalDate.now();
    date = LocalDate.parse("2020-08-20");
    System.out.println(date);

    // 获取当前时间,包含毫秒数
    LocalTime now = LocalTime.now();
    System.out.println(now);
    
结果：10:59:01.532

    LocalTime localTime = LocalTime.of(13, 30, 59);
    System.out.println(localTime);
    
结果：13:30:59

    LocalTime now = LocalTime.now();
    LocalTime localTime = now.withNano(0);
    System.out.println(localTime);

结果：11:02:07

     LocalTime localTime = LocalTime.parse("11:05:20");
    System.out.println(localTime);

结果：11:05:20

    LocalTime time = LocalTime.now();
    System.out.println("当前时间" + time);
    // 获取 时，分，秒，纳秒
    int hour = time.getHour();
    int minute = time.getMinute();
    int second = time.getSecond();
    int nano = time.getNano();
    System.out.println( hour + "时" + minute + "分" + second + "秒" + nano + "纳秒");

结果：
当前时间11:27:14.161
11时27分14秒161000000纳秒

    LocalDateTime time = LocalDateTime.now();
    System.out.println(time);

结果：2020-08-20T11:07:45.217

    String date = "2020-08-20 11:08:10";
    DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
    LocalDateTime time = LocalDateTime.parse(date, dateTimeFormatter);
    System.out.println(time);

结果：2020-08-20T11:08:10

    String date="2020-08-20 11:08:10";
    DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
    LocalDateTime time = LocalDateTime.parse(date, dateTimeFormatter);
    long l = time.toEpochSecond(ZoneOffset.of("+9"));
    System.out.println(l);

结果：1597889290

    DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
    String time = dateTimeFormatter.format(LocalDateTime.now());
    System.out.println(time);

结果：2020-08-20 11:13:39

    /** 时间 **/
    LocalDateTime dateTime = LocalDateTime.now();
    System.out.println("LocalDateTime：" + dateTime);
    // LocalDateTime实际上就是 日期类+时间类的组合，所以也可以LocalDate和LocalTime的一些方法
    int year = dateTime.getYear();
    int month = dateTime.getMonthValue();
    int day = dateTime.getDayOfMonth();
    int hour = dateTime.getHour();
    int minute = dateTime.getMinute();
    int second = dateTime.getSecond();
    int nano = dateTime.getNano();
    System.out.println(year + "年" + month + "月" + day + "日" + hour + "时" + minute + "分" + second + "秒" + nano + "纳秒");

结果：
当前时间：2020-08-20T11:32:10.978
2020年8月20日11时32分10秒978000000纳秒