Java ChronoLocalDateTime format()用法及代码示例

Java中ChronoLocalDateTime接口的format()方法使用指定的格式化程序格式化此date-time。

用法:

default String format(DateTimeFormatter formatter)

参数：此方法接受参数格式化程序，该参数格式化程序指定要使用的DateTimeFormatter，而不是null。

返回值：该函数返回格式化的日期字符串，而不是null。

以下示例程序旨在说明ChronoLocalDateTime.format()方法：

示例1:

// Java program to illustrate the format() method 
  
import java.util.*; 
import java.time.*; 
import java.time.chrono.*; 
import java.time.format.DateTimeFormatter; 
  
public class GfG { 
    public static void main(String[] args) 
    { 
        // Parses the date 
        ChronoLocalDateTime dt1 
            = LocalDateTime 
                  .parse("2018-11-03T12:45:30"); 
  
        // Prints the date 
        System.out.println("Original ChronoLocalDateTime: "
                           + dt1); 
  
        // Display d1 in different formats 
        // using format() method 
        System.out.println("BASIC_ISO_DATE format: "
                           + (DateTimeFormatter.BASIC_ISO_DATE) 
                                 .format(dt1)); 
        System.out.println("ISO_LOCAL_DATE format: "
                           + (DateTimeFormatter.ISO_LOCAL_DATE) 
                                 .format(dt1)); 
        System.out.println("ISO_DATE format: "
                           + (DateTimeFormatter.ISO_DATE) 
                                 .format(dt1)); 
        System.out.println("ISO_LOCAL_TIME format: "
                           + (DateTimeFormatter.ISO_LOCAL_TIME) 
                                 .format(dt1)); 
    } 
}

输出：

Original ChronoLocalDateTime: 2018-11-03T12:45:30
BASIC_ISO_DATE format: 20181103
ISO_LOCAL_DATE format: 2018-11-03
ISO_DATE format: 2018-11-03
ISO_LOCAL_TIME format: 12:45:30

示例2:

// Program to illustrate the format() method 
  
import java.util.*; 
import java.time.*; 
import java.time.chrono.*; 
import java.time.format.DateTimeFormatter; 
  
public class GfG { 
    public static void main(String[] args) 
    { 
        // Parses the date 
        ChronoLocalDateTime dt1 
            = LocalDateTime 
                  .parse("2016-09-06T12:45:30"); 
  
        // Prints the date 
        System.out.println(dt1); 
  
        // Display d1 in different formats 
        // using format() method 
        System.out.println("ISO_TIME format: "
                           + (DateTimeFormatter.ISO_TIME) 
                                 .format(dt1)); 
        System.out.println("ISO_LOCAL_DATE_TIME format: "
                           + (DateTimeFormatter.ISO_LOCAL_DATE_TIME) 
                                 .format(dt1)); 
        System.out.println("ISO_DATE_TIME format: "
                           + (DateTimeFormatter.ISO_DATE_TIME) 
                                 .format(dt1)); 
        System.out.println("ISO_ORDINAL_DATE format: "
                           + (DateTimeFormatter.ISO_ORDINAL_DATE) 
                                 .format(dt1)); 
        System.out.println("ISO_WEEK_DATE format: "
                           + (DateTimeFormatter.ISO_WEEK_DATE) 
                                 .format(dt1)); 
    } 
}

输出：

2016-09-06T12:45:30
ISO_TIME format: 12:45:30
ISO_LOCAL_DATE_TIME format: 2016-09-06T12:45:30
ISO_DATE_TIME format: 2016-09-06T12:45:30
ISO_ORDINAL_DATE format: 2016-250
ISO_WEEK_DATE format: 2016-W36-2

参考： https://docs.oracle.com/javase/9/docs/api/java/time/chrono/ChronoLocalDateTime.html#format-java.time.format.DateTimeFormatter-

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注：本文由纯净天空筛选整理自srinam大神的英文原创作品 ChronoLocalDateTime format() method in Java with Examples。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。