Java LocalDateTime parse() Method

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The parse() method in Java, part of the java.time.LocalDateTime class, is used to obtain an instance of LocalDateTime from a string representation using a specified formatter. This method is useful for converting date-time strings into LocalDateTime instances.

Table of Contents

1. Introduction
2. parse() Method Syntax
3. Understanding parse()
4. Examples
   • Basic Usage
   • Using parse() with Custom Formatters
5. Real-World Use Case
6. Conclusion

Introduction

The parse() method allows you to convert a string representation of a date-time into a LocalDateTime instance. This is particularly useful for reading date-time values from text input or files and converting them into LocalDateTime objects for further processing.

parse() Method Syntax

The parse() method has two overloads:

Overload 1: Using Default Formatter

public static LocalDateTime parse(CharSequence text) 

Overload 2: Using Custom Formatter

public static LocalDateTime parse(CharSequence text, DateTimeFormatter formatter) 

Parameters:

• text: The text to parse, not null.
• formatter: The formatter to use, not null (for the second overload).

Returns:

• A LocalDateTime parsed from the text, not null.

Throws:

• DateTimeParseException if the text cannot be parsed.

Understanding parse()

The parse() method parses a text string to produce a LocalDateTime instance. The method can use either the default ISO date-time format or a custom format specified by a DateTimeFormatter.

Examples

Basic Usage

To demonstrate the basic usage of parse(), we will parse a date-time string using the default formatter.

Example

import java.time.LocalDateTime; public class LocalDateTimeParseExample { public static void main(String[] args) { String dateTimeString = "2023-06-15T10:30"; LocalDateTime dateTime = LocalDateTime.parse(dateTimeString); System.out.println("Parsed DateTime: " + dateTime); } } 

Output:

Parsed DateTime: 2023-06-15T10:30 

Using parse() with Custom Formatters

This example shows how to use the parse() method with a custom formatter to parse a date-time string.

Example

import java.time.LocalDateTime; import java.time.format.DateTimeFormatter; public class LocalDateTimeParseCustomFormatterExample { public static void main(String[] args) { String dateTimeString = "15-06-2023 10:30:45"; DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd-MM-yyyy HH:mm:ss"); LocalDateTime dateTime = LocalDateTime.parse(dateTimeString, formatter); System.out.println("Parsed DateTime: " + dateTime); } } 

Output:

Parsed DateTime: 2023-06-15T10:30:45 

Real-World Use Case

Reading Date-Time from Input

In real-world applications, the parse() method can be used to read date-time values from user input or text files and convert them into LocalDateTime instances for further processing.

Example

import java.time.LocalDateTime; import java.time.format.DateTimeFormatter; import java.util.Scanner; public class DateTimeInputExample { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); System.out.println("Enter date and time in format dd-MM-yyyy HH:mm:ss:"); String input = scanner.nextLine(); DateTimeFormatter formatter = DateTimeFormatter.ofPattern("dd-MM-yyyy HH:mm:ss"); LocalDateTime dateTime = LocalDateTime.parse(input, formatter); System.out.println("Parsed DateTime: " + dateTime); } } 

Output:

Enter date and time in format dd-MM-yyyy HH:mm:ss: 15-06-2023 10:30:45 Parsed DateTime: 2023-06-15T10:30:45 

Conclusion

The LocalDateTime.parse() method is used to convert a string representation of a date-time into a LocalDateTime instance. This method is particularly useful for reading date-time values from text input or files and converting them into LocalDateTime objects for further processing. By understanding and using the parse() method, you can effectively manage and manipulate date-time data in your Java applications.