How to Format LocalDateTime in Java
Java examples to format LocalDateTime instance to String using DateTimeFormatter class.
1. Default Format with LocalDateTime.toString()
By default, LocalDateTime format in the following ISO-8601 formats based on the available date and times parts:
uuuu-MM-dd'T'HH:mm uuuu-MM-dd'T'HH:mm:ss uuuu-MM-dd'T'HH:mm:ss.SSS uuuu-MM-dd'T'HH:mm:ss.SSSSSS uuuu-MM-dd'T'HH:mm:ss.SSSSSSSSSSystem.out.println( LocalDateTime.now() ); //2022-12-09T18:19:26.4927454002. LocalDateTime.format() Method
The format() method formats the given LocalDateTime instance using the specified format by DateTimeFormatter instance. It throws DateTimeException – if an error occurs during formatting.
public String format(DateTimeFormatter formatter)Note that DateTimeFormatter is immutable and thread-safe, and thus the recommended approach is to store it in a static constant where possible. We should not need to create new instances everytime we use it.
3. LocalDateTime Format Examples
In the given example, we have created a new instance using LocalDateTime.now() representing the current date and time. We are using an inbuilt DateTimeFormatter instance using the constant ISO_DATE_TIME. There are several inbuilt patterns available for other frequently used date-time formats.
Finally, use the format() method to get the formatted string.
final static DateTimeFormatter ISO_FORMATTER = DateTimeFormatter.ISO_DATE_TIME; LocalDateTime ldt = LocalDateTime.now(); String formattedDateTime = ldt.format(ISO_FORMATTER); //2022-12-09T18:25:58.6037597Use ofPattern() method if you want to use a custom pattern for formatting.
final static DateTimeFormatter CUSTOM_FORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss"); LocalDateTime ldt = LocalDateTime.now(); String formattedString = ldt.format(CUSTOM_FORMATTER); //2022-12-09 18:25:584. Parsing a String to LocalDateTime
The following example parses a given date-time String to LocalDateTime instance. It uses the parse(dateTimeString, formatter) for parsing the given dateTimeString using the provided formatter.
//date in String String dateString = "2018-07-14T17:45:55.9483536"; DateTimeFormatter formatter = DateTimeFormatter.ISO_DATE_TIME; //Parse String to LocalDateTime LocalDateTime dateTime = LocalDateTime.parse(dateString, formatter);