Java 8 - How to convert String to LocalDate and LocalDate to String in specific format
This Java 8 code tip first shows how to convert
String date to java.time.LocalDate instance using the parse() method of java.time.DateTimeFormatter class. It then shows how to use the format() method of LocalDate class to convert LocalDate instance to a String in the specified format.
[su_box title="Java 8 code to convert String to LocalDate" style="soft" box_color="#fcba43" title_color="#00000" radius="4" Class="for-shortcodebox"][java]package com.javabrahman.java8.time;
import java.time.LocalDate;
import java.time.format.DateTimeFormatter;
public class StringToLocalDate {
public static void main(String args[]){
//Converting String in format 'dd-MMM-yyyy' to LocalDate
String dateStr_1="28-Sep-2016";
DateTimeFormatter formatter_1=DateTimeFormatter.ofPattern("dd-MMM-yyyy");
LocalDate localDate_1= LocalDate.parse(dateStr_1,formatter_1);
System.out.println("Input String with value: "+dateStr_1);
System.out.println("Converted Date in default ISO format: "+localDate_1+"\n");
//Converting String in format 'EEEE, MMM d yyyy' to LocalDate
String dateStr_2="Wednesday, Sep 28 2016";
DateTimeFormatter formatter_2=DateTimeFormatter.ofPattern("EEEE, MMM d yyyy");
LocalDate localDate_2= LocalDate.parse(dateStr_2,formatter_2);
System.out.println("Input String with value: "+dateStr_2);
System.out.println("Converted Date in default ISO format: "+localDate_2+"\n");
//Converting String in format 'dd/MM/YY' to LocalDate
String dateStr_3="28/09/16";
DateTimeFormatter formatter_3=DateTimeFormatter.ofPattern("dd/MM/yy");
LocalDate localDate_3= LocalDate.parse(dateStr_3,formatter_3);
System.out.println("Input String with value: "+dateStr_3);
System.out.println("Converted Date in default ISO format: "+localDate_3);
}
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OUTPUT of the above code[su_note note_color="#1a1a1a" text_color="#DAD9D7"]Input String with value: 28-Sep-2016
Converted Date in default ISO format: 2016-09-28
Input String with value: Wednesday, Sep 28 2016
Converted Date in default ISO format: 2016-09-28
Input String with value: 28/09/16
Converted Date in default ISO format: 2016-09-28[/su_note]
Explanation of the code
- We start by creating a
Stringwith value28-Sep-2016, nameddateStr_1, which we then convert to aLocalDate. - We need to convey to the Java 8 Date-Time API the format in which the date is being given to it inside
dateStr_1. This format is specified using theDateTimeFormatterclass. We pass the format of the datedd-MMM-yyyytoDateTimeFormatter’s static method namedofPattern(). ofPattern()method returns an instance ofDateTimeFormatter, namedformatter_1, with the required date format set in it.- We then pass the
dateStr_1andformatter_1as inputs to theLocalDate.parse()method which creates an instance ofLocalDate, namedlocalDate_1, with the value as 28th of September 2016. - We then print
localDate_1which prints the date as2016-09-28which is in the Standard ISO Format for dates. - Similarly, two other date formats are shown as examples to show how the date formats work resulting in dates
localDate_2andlocalDate_3. These are also printed in the default ISO format to show that theStringhas been converted properly to its equivalentLocalDate. - To print dates in formats other than the default ISO format, we will need to use the
LocalDate.format()method. The next section of this article shows how to format aLocalDateinto formats other than the default ISO format.
- We start by creating a
LocalDateinstance, namedtoday, using theLocalDate.now()method. Objecttodayholds the system date for today. We then printtodayand it is in the default ISO format as expected i.e.2016-09-28. - We then create a
SimpleDateFormatter, namedformatter_1, using its staticofPattern()method to which we pass the required date format as aStringcontainingdd-MMM-yyyy. - Next we invoke the
format()method ontodayobject withformatter_1as the input containing the format in which we need theStringequivalent oftoday. - The
format()method returns aString, namedformat_1, containing the date in the required format i.e.28-Sep-2016, which is then printed as output. - Similarly,
todayis printed in two different formats, as Stringsformat_2andformat_3, as shown in the output -28/09/2016andWed,28 Sep 2016.
Tutorials on Java 8’s new Date and Time API
Overview of Java 8's new Date and Time APIClick to Read Overview of Java 8's new Date-Time API Working with time zones in Java 8| ZonedDateTime, ZoneId tutorial with examplesClick to Read tutorial on time zone handling in Java 8 How to convert LocalDate to String and String to LocalDateClick to Read tutorial on String to LocalDate conversions How to convert java.util.Date to java.time.LocalDateClick to Read tutorial on java.util.Date to LocalDate conversion Formatting localized dates in Spanish and FrenchClick to Read date formatting in Spanish & French How to get day-of-week for a given dateHow to get day-of-week using java.time.DayOfWeek enumDate Modification using TemporalAdjuster Click to Read Tutorial on TemporalAdjusters
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