java DateTimeFormatter 格式化日期

package com.test;

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.format.DateTimeFormatter;

public class DateTimeFormatterTest {
    public static final DateTimeFormatter YYYY_MM_DD_HH_MM_SS  = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss");
    public static void main(String[] args) {


        System.out.println(LocalDateTime.now().format(YYYY_MM_DD_HH_MM_SS));

    }
}