Date Format conversion

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Important code snippet for Date conversions and methods-

Here we are covering different conversion of date more frequently used-

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Covert Date String to Date object

package com.featuretest.basics;

import java.text.ParseException;

import java.text.SimpleDateFormat;

import java.util.Date;

class TestMain {

public static void main(String[] args) throws ParseException {

      String dateString = "31/05/1988";

      Date dateObj = new SimpleDateFormat("dd/MM/yyyy").parse(dateString);

      System.out.println(dateString + "\t" + dateObj);

}

}

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Covert Date object to localDateTime

package com.featuretest.basics;

import java.text.ParseException;

import java.time.LocalDateTime;

import java.time.ZoneId;

import java.util.Date;

class TestMain {

public static void main(String[] args) throws ParseException {

      Date date = new Date();

      LocalDateTime localDateTime = date.toInstant().atZone(ZoneId.systemDefault()).toLocalDateTime();

      System.out.println(localDateTime);

}

}

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Date conversion from one format to another

package com.featuretest.basics;

import java.text.ParseException;

import java.text.SimpleDateFormat;

import java.time.LocalDate;

import java.time.LocalDateTime;

import java.time.format.DateTimeFormatter;

import java.util.Date;

class TestMain {

public static void main(String[] args) {

String dateString = "2019-12-19 04:10:00";

String convertedDate = dateFormatConversion(dateString, "yyyy-MM-dd hh:mm:ss", "yyyy-MM-dd");

System.out.println(convertedDate);

           

// Using Java 8 DateTime API

String convertedDateJava8 = dateFormatConversionJava8(dateString, "yyyy-MM-dd hh:mm:ss", "yyyy-MM-dd");

System.out.println(convertedDateJava8);

}

     

private static String dateFormatConversion(String dateString, String inputDF, String outputDF) {

SimpleDateFormat sdf = new SimpleDateFormat(inputDF);

Date date = null;

try {

      date = sdf.parse(dateString);

} catch (ParseException e) {

      e.printStackTrace();

}

SimpleDateFormat newFormat = new SimpleDateFormat(outputDF);

String output = newFormat.format(date);

return output;

}

     

private static String dateFormatConversionJava8(String dateString, String inputDF, String outputDF) {

DateTimeFormatter oldDTF = DateTimeFormatter.ofPattern(inputDF);

DateTimeFormatter newDTF = DateTimeFormatter.ofPattern(outputDF);

LocalDateTime datetime = LocalDateTime.from(LocalDate.parse(dateString, oldDTF).atStartOfDay());

return datetime.format(newDTF);

}

}