Category Archives: Date

JAVA : Daylight Saving Time (DST) Handling


Pre-Requisite : Java : Date and Time Handling Tutorial

Most of the United States practice of advancing clock during summer month in order to leverage an additional hour of natural light(saving heating power, illumination power, enhancing the mood, and so on).

When clocks change time

In United States Daylight Saving Time begins at 2:00 a.m. on the second Sunday in March and reverts to standard time on the first Sunday in November. In United States each time zone switches clocks at different time.

Daylight Saving Time on time zone

In United States , When Daylight Saving Time are being followed in EST then it’s become EDT. These names just are abbreviation and having different meaning in different continents.
Ex:

  • IST : Indian Standard Time
  • IST : Irish Standard Time
  • IST : Israel Standard Time

For United States (Follow Day Light Saving)

Standard Time Daylight Savings Time
CST : Central Standard Time (North America) CDT : Central Daylight Time
EST : Eastern Standard Time (North America) EDT : Eastern Daylight Time
PST : Pacific Standard Time (North America) PDT : Pacific Daylight Time

Complete List of timezone abbreviations

Note : The 3-letter abbreviations should be wholeheartedly avoided in favor of TZDB zone IDs. EST is not time zone such 3-4 letter codes are neither standardized nor unique, and further the confusion over Daylight saving time (DST). Whenever need to set time zone in code in the code always use proper time zone name in the “continent/region” format.

Complete List of time zone with continent/region

Example of Daylight Saving Time with Time Zone

In this example cover all the case for applying Daylight Saving Time on different time zone. Here I have try to apply with abbreviation, continent / region and show with standard time and Daylight saving time.

package datetime;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.time.ZoneId;
import java.util.Date;
import java.util.TimeZone;

public class DayLightSavingExample {

	public static void main(String[] args) {
	/**
	* DST = Daylight Saving Time (Begins Daylight Saving Time at 2:00 a.m.
	* on the second Sunday in March and reverts to standard time on the
	* first Sunday in November)
	*/
	SimpleDateFormat sourceFormat = new SimpleDateFormat("MM/dd/yyyy");
	SimpleDateFormat targetFormat = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'+|-hh:mm");
	String strWithDLS = "03/10/2019"; // MM/DD/YYYY
	String strWithOutDLS = "03/11/2019";
	try {
	     Date dateWithDLS = sourceFormat.parse(strWithDLS);
	     Date dateWithOutDLS = sourceFormat.parse(strWithOutDLS);
		System.out.println("Default Timezone with Day Light Saving :" + targetFormat.format(dateWithDLS));
		System.out.println("Default Timezone without Day Light Saving :" + targetFormat.format(dateWithOutDLS));

		/**
		* Set time zone with EST (No difference in time) because 3 letter
		* time zone not consider DST (Day light saving time)
		*/
		sourceFormat.setTimeZone(TimeZone.getTimeZone("EST"));
		dateWithDLS = sourceFormat.parse(strWithDLS);
		dateWithOutDLS = sourceFormat.parse(strWithOutDLS);
		System.out.println("EST Timezone with Day Light Saving :" + targetFormat.format(dateWithDLS));
		System.out.println("EST Timezone without Day Light Saving :" + targetFormat.format(dateWithOutDLS));

		/**
		* Set time zone with America/New_York (1 hour difference in time)
		* when you need to use day light saving always use with
		* continent/region format.
		*/
			sourceFormat.setTimeZone(TimeZone.getTimeZone(ZoneId.of("America/New_York")));
dateWithDLS = sourceFormat.parse(strWithDLS);
dateWithOutDLS = sourceFormat.parse(strWithOutDLS);
System.out.println("America/New_York Timezone with Day Light Saving :" + targetFormat.format(dateWithDLS));
System.out.println(
"America/New_York Timezone without Day Light Saving :" + targetFormat.format(dateWithOutDLS));

} catch (ParseException ex) {
			ex.printStackTrace();
}

	}

}

Output :


Default Timezone with Day Light Saving :2019-03-10T00:00:00Z+|-12:00
Default Timezone without Day Light Saving :2019-03-11T00:00:00Z+|-12:00
EST Timezone with Day Light Saving :2019-03-10T10:30:00Z+|-10:30
EST Timezone without Day Light Saving :2019-03-11T10:30:00Z+|-10:30
America/New_York Timezone with Day Light Saving :2019-03-10T10:30:00Z+|-10:30
America/New_York Timezone without Day Light Saving :2019-03-11T09:30:00Z+|-09:30

 

Here i have tried to cover all the points as developer prospects. If you know more ways to handle it and any issues related to date and time please suggest in comments.

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Java 8+ Date Time Exmples


Pre-Requisite : Java Date and Time Tutorial

In this below example try to cover all possible cases and operations with date and time with Java 8+ APIs.

import java.time.DateTimeException;
import java.time.Duration;
import java.time.Instant;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.Month;
import java.time.Period;
import java.time.ZoneId;
import java.time.ZoneOffset;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;
import java.time.temporal.ChronoUnit;
import java.time.temporal.Temporal;
import java.time.temporal.TemporalAdjusters;
import java.time.zone.ZoneRulesException;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.TimeZone;

public class Java8DateTime {

	public static void main(String[] args) {
		//LocalDate lastDay_2014 = LocalDate.of(2014, 12, 32);
		//LocalTime lastDay_2014 = LocalTime.of(12, 12, 23,-1);
		currentDateTime();
		instantAPI();
		GregorianCalendarAPI();
		TimeZoneAPI();
		dateTimeFormattingAndParsing();
		localDateAPI();
		localDateTimeAPI();
		localTimeAPI();

		System.out.println("*********Set Date and Time Manually***************");
		LocalDateTime dateTimePoint=LocalDateTime.now();
		// Set Date and Time manually
		LocalDate datePoint = LocalDate.of(2012, Month.DECEMBER, 12);
		System.out.println("Local Date :" + datePoint);
		// Days after 1970
		datePoint = LocalDate.ofEpochDay(150);
		System.out.println("Local Date :" + datePoint);
		// set String
		LocalTime timePoint = LocalTime.parse("10:15:30");
		System.out.println("Local Time :" + timePoint);
		// Set hours and minutes
		timePoint = LocalTime.of(13, 18);
		System.out.println("Local Time :" + timePoint);

		// Retrieve values
		System.out.println("*********Get Date and Time Values***************");
		datePoint = dateTimePoint.toLocalDate();
		Month month = dateTimePoint.getMonth();
		int day = dateTimePoint.getDayOfMonth();
		int year = dateTimePoint.getYear();
		int hour = dateTimePoint.getHour();
		int minute = dateTimePoint.getMinute();
		int second = dateTimePoint.getSecond();
		System.out.println("Local Date :" + datePoint);
		System.out.printf("Local Date time Format : %d/%d/%d %d:%d:%d", day, month.getValue(), year, hour, minute,
				second);
		System.out.println();
		System.out.println("*********Operation On LocalDate***************");
		// Operation on Local Date
		// Period of 1 year 3 month 2 days
		Period period = Period.of(1, 3, 2);
		LocalDate startDatePoint = datePoint.minus(period);
		System.out.println("Local Date :" + startDatePoint);
		LocalDate endDatePoint = datePoint.plus(period);
		System.out.println("Local Date :" + endDatePoint);

		System.out.println("*********Diffrence of On LocalDate***************");
		// Difference of Date
		Period daysPeriod = Period.between(startDatePoint, endDatePoint);
		System.out.println("Days :" + daysPeriod.getDays());
		System.out.println("Months :" + daysPeriod.getMonths());
		System.out.println("Years :" + daysPeriod.getYears());
		// Another Way
		long days = ChronoUnit.DAYS.between(startDatePoint, endDatePoint);
		long months = ChronoUnit.MONTHS.between(startDatePoint, endDatePoint);
		long years = ChronoUnit.YEARS.between(startDatePoint, endDatePoint);
		System.out.println("Days :" + days);
		System.out.println("Months :" + months);
		System.out.println("Years :" + years);

		// Duration

		// A duration of 3 seconds and 5 nanoseconds
		Duration duration = Duration.ofSeconds(3, 5);
		// Duration oneDay = Duration.between(Temporal., yesterday);

	}

	private static void currentDateTime() {
		System.out.println("*********Current Date and Time***************");

		// Current Date and Time
		LocalDateTime dateTimePoint = LocalDateTime.now();
		System.out.println("Local Date Time :" + dateTimePoint);
		// Current Date
		LocalDate datePoint = LocalDate.now();
		System.out.println("Local Date :" + datePoint);
		// Current Time
		LocalTime timePoint = LocalTime.now();
		System.out.println("Local Time :" + timePoint);

		// Get Instant from java.util.Date
		Instant timestamp = new Date().toInstant();
		System.out.println("Current Timestamp = " + timestamp);

		// java.util.Calendar to Instant
		Instant time = Calendar.getInstance().toInstant();
		System.out.println(time);
	}

	private static void instantAPI() {
		System.out.println("*****************Instant API*******************");
		// Date to Instant
		Instant timestamp = new Date().toInstant();
		System.out.println("Current Timestamp = " + timestamp);
		// Now we can convert Instant to LocalDateTime or other similar classes
		LocalDateTime date = LocalDateTime.ofInstant(timestamp, ZoneId.of(ZoneId.SHORT_IDS.get("PST")));
		System.out.println("Date = " + date);

		// Calendar to Instant
		Instant time = Calendar.getInstance().toInstant();
		System.out.println(time);

		// Date API to Legacy classes
		Date dt = Date.from(Instant.now());
		System.out.println(dt);

		// Instant from timestamp
		Instant specificTime = Instant.ofEpochMilli(timestamp.toEpochMilli());
		System.out.println("Specific Time = " + specificTime);

		// Duration example
		Duration thirtyDay = Duration.ofDays(30);
		System.out.println(thirtyDay);
	}

	private static void localDateAPI() {
		System.out.println("*****************Local Date API*******************");
		LocalDate today = LocalDate.now();

		System.out.println("Current Date=" + today);

		// Creating LocalDate by providing input parameters.
		// Here are chnaces of getting DateTimeException if pass as Invalidate
		// Date format
		LocalDate firstDay_2016 = LocalDate.of(2016, Month.JANUARY, 1);
		System.out.println("Specific Date=" + firstDay_2016);

		try {
			// Here with throw DateTimeException if pass as Invalidate Date
			// format
			LocalDate lastDay_2014 = LocalDate.of(2014, Month.FEBRUARY, 29);
			System.out.println("Specific Date=" + lastDay_2014);
		} catch (DateTimeException ex) {
			ex.printStackTrace();
		}

		// Current date in "Asia/Kolkata", you can get it from ZoneId
		LocalDate todayKolkata = LocalDate.now(ZoneId.of("Asia/Kolkata"));
		System.out.println("Current Date in CST=" + todayKolkata);

		try
		{
		// Will throw java.time.zone.ZoneRulesException: Unknown time-zone ID: IST
		LocalDate todayIST = LocalDate.now(ZoneId.of("IST"));
		}
		catch(ZoneRulesException ex)
		{
			ex.printStackTrace();
		}

		// Getting date from the base date i.e 01/01/1970
		LocalDate dateFromBase = LocalDate.ofEpochDay(365);
		System.out.println("365th day from base date= " + dateFromBase);

        //Get 100 th day of year
		LocalDate hundredDay2014 = LocalDate.ofYearDay(2016, 100);
		System.out.println("100th day of 2014=" + hundredDay2014);

		//Other APIs and Operation on LocalDate

		// Get the Year, check if it's leap year
		System.out.println("Year " + today.getYear() + " is Leap Year? " + today.isLeapYear());

		// Compare two LocalDate for before and after
		System.out.println("Today is before 01/01/2017? " + today.isBefore(LocalDate.of(2017, 1, 1)));

		// Get LocalDateTime from LocalDate
		System.out.println("Current Time=" + today.atTime(LocalTime.now()));

		// plus and minus operations
		System.out.println("20 days after today will be " + today.plusDays(20));
		System.out.println("5 weeks after today will be " + today.plusWeeks(5));
		System.out.println("30 months after today will be " + today.plusMonths(30));

		System.out.println("20 days before today will be " + today.minusDays(20));
		System.out.println("5 weeks before today will be " + today.minusWeeks(5));
		System.out.println("30 months before today will be " + today.minusMonths(30));

		// TemporalAdjusters for adjusting the dates
		LocalDate firstDayOfMonth=today.with(TemporalAdjusters.firstDayOfMonth());
		System.out.println("First date of this month= " + firstDayOfMonth);

		LocalDate lastDayOfYear = today.with(TemporalAdjusters.lastDayOfYear());
		System.out.println("Last date of this year= " + lastDayOfYear);

		Period period = today.until(lastDayOfYear);
		System.out.println("Period Format= " + period);
		System.out.println("Months remaining in the year= " + period.getMonths());

	}

	private static void localTimeAPI() {
		System.out.println("*****************Local Time API*******************");
		// Current Time
		LocalTime time = LocalTime.now();
		System.out.println("Current Time=" + time);

		// Creating LocalTime by providing input arguments
		LocalTime specificTime = LocalTime.of(12, 20, 25, 40);
		System.out.println("Specific Time of Day=" + specificTime);

		// Try creating time by providing invalid inputs
		// LocalTime invalidTime = LocalTime.of(25,20);
		// Exception in thread "main" java.time.DateTimeException:
		// Invalid value for HourOfDay (valid values 0 - 23): 25

		// Current date in "Asia/Kolkata", you can get it from ZoneId javadoc
		LocalTime timeKolkata = LocalTime.now(ZoneId.of("Asia/Kolkata"));
		System.out.println("Current Time in IST=" + timeKolkata);

		// java.time.zone.ZoneRulesException: Unknown time-zone ID: IST
		// LocalTime todayIST = LocalTime.now(ZoneId.of("IST"));

		// Getting date from the base date i.e 01/01/1970
		LocalTime specificSecondTime = LocalTime.ofSecondOfDay(10000);
		System.out.println("10000th second time= " + specificSecondTime);

	}

	private static void localDateTimeAPI() {
		System.out.println("*****************Local Date Time API*******************");
		// Current Date
		LocalDateTime today = LocalDateTime.now();
		System.out.println("Current DateTime=" + today);

		// Current Date using LocalDate and LocalTime
		today = LocalDateTime.of(LocalDate.now(), LocalTime.now());
		System.out.println("Current DateTime=" + today);

		// Creating LocalDateTime by providing input arguments
		LocalDateTime specificDate = LocalDateTime.of(2014, Month.JANUARY, 1, 10, 10, 30);
		System.out.println("Specific Date=" + specificDate);

		// Try creating date by providing invalid inputs
		// LocalDateTime feb29_2014 = LocalDateTime.of(2014, Month.FEBRUARY, 28,
		// 25,1,1);
		// Exception in thread "main" java.time.DateTimeException:
		// Invalid value for HourOfDay (valid values 0 - 23): 25

		// Current date in "Asia/Kolkata", you can get it from ZoneId javadoc
		LocalDateTime todayKolkata = LocalDateTime.now(ZoneId.of("Asia/Kolkata"));
		System.out.println("Current Date in IST=" + todayKolkata);

		// java.time.zone.ZoneRulesException: Unknown time-zone ID: IST
		// LocalDateTime todayIST = LocalDateTime.now(ZoneId.of("IST"));

		// Getting date from the base date i.e 01/01/1970
		LocalDateTime dateFromBase = LocalDateTime.ofEpochSecond(10000, 0, ZoneOffset.UTC);
		System.out.println("10000th second time from 01/01/1970= " + dateFromBase);

	}

	private static void dateTimeFormattingAndParsing() {
		System.out.println("*****************Local DateTime Formatting API*******************");
		// Format examples
		LocalDate date = LocalDate.now();
		// default format
		System.out.println("Default format of LocalDate=" + date);
		// specific format
		System.out.println(date.format(DateTimeFormatter.ofPattern("d::MMM::uuuu")));
		System.out.println(date.format(DateTimeFormatter.BASIC_ISO_DATE));

		LocalDateTime dateTime = LocalDateTime.now();
		// default format
		System.out.println("Default format of LocalDateTime=" + dateTime);
		// specific format
		System.out.println(dateTime.format(DateTimeFormatter.ofPattern("d::MMM::uuuu HH::mm::ss")));
		System.out.println(dateTime.format(DateTimeFormatter.BASIC_ISO_DATE));

		Instant timestamp = Instant.now();
		// default format
		System.out.println("Default format of Instant=" + timestamp);

		// Parse examples
		LocalDateTime dt = LocalDateTime.parse("27::Apr::2014 21::39::48",
				DateTimeFormatter.ofPattern("d::MMM::uuuu HH::mm::ss"));
		System.out.println("Default format after parsing = " + dt);

	}

	private static void GregorianCalendarAPI() {
		System.out.println("*****************Gregorian Calendar API*******************");
		// ZonedDateTime from specific Calendar
		ZonedDateTime gregorianCalendarDateTime = new GregorianCalendar().toZonedDateTime();
		System.out.println(gregorianCalendarDateTime);

		GregorianCalendar gc = GregorianCalendar.from(gregorianCalendarDateTime);
		System.out.println(gc);
	}

	private static void TimeZoneAPI() {
		System.out.println("*****************Time Zone API*******************");
		// TimeZone to ZoneId
		ZoneId defaultZone = TimeZone.getDefault().toZoneId();
		System.out.println(defaultZone);

		TimeZone tz = TimeZone.getTimeZone(defaultZone);
		System.out.println(tz);

	}

}

Output


*********Current Date and Time***************
Local Date Time :2019-05-16T11:50:59.302
Local Date :2019-05-16
Local Time :11:50:59.303
Current Timestamp = 2019-05-16T06:20:59.303Z
2019-05-16T06:20:59.358Z
*****************Instant API*******************
Current Timestamp = 2019-05-16T06:20:59.369Z
Date = 2019-05-15T23:20:59.369
2019-05-16T06:20:59.373Z
Thu May 16 11:50:59 IST 2019
Specific Time = 2019-05-16T06:20:59.369Z
PT720H
*****************Gregorian Calendar API*******************
2019-05-16T11:50:59.387+05:30[Asia/Calcutta]
java.util.GregorianCalendar[time=1557987659387,areFieldsSet=true,areAllFieldsSet=true,lenient=true,zone=sun.util.calendar.ZoneInfo[id="Asia/Calcutta",offset=19800000,dstSavings=0,useDaylight=false,transitions=7,lastRule=null],firstDayOfWeek=2,minimalDaysInFirstWeek=4,ERA=1,YEAR=2019,MONTH=4,WEEK_OF_YEAR=20,WEEK_OF_MONTH=3,DAY_OF_MONTH=16,DAY_OF_YEAR=136,DAY_OF_WEEK=5,DAY_OF_WEEK_IN_MONTH=3,AM_PM=0,HOUR=11,HOUR_OF_DAY=11,MINUTE=50,SECOND=59,MILLISECOND=387,ZONE_OFFSET=19800000,DST_OFFSET=0]
*****************Time Zone API*******************
Asia/Calcutta
sun.util.calendar.ZoneInfo[id="Asia/Calcutta",offset=19800000,dstSavings=0,useDaylight=false,transitions=7,lastRule=null]
*****************Local DateTime Formatting API*******************
Default format of LocalDate=2019-05-16
16::May::2019
20190516
Default format of LocalDateTime=2019-05-16T11:50:59.551
16::May::2019 11::50::59
20190516
Default format of Instant=2019-05-16T06:20:59.551Z
Default format after parsing = 2014-04-27T21:39:48
*****************Local Date API*******************
Current Date=2019-05-16
Specific Date=2016-01-01
java.time.DateTimeException: Invalid date 'February 29' as '2014' is not a leap year
Current Date in CST=2019-05-16
365th day from base date= 1971-01-01
    at java.time.LocalDate.create(Unknown Source)
    at java.time.LocalDate.of(Unknown Source)
    at datetime.Java8DateTime.localDateAPI(Java8DateTime.java:160)
    at datetime.Java8DateTime.main(Java8DateTime.java:34)
java.time.zone.ZoneRulesException: Unknown time-zone ID: IST
    at java.time.zone.ZoneRulesProvider.getProvider(Unknown Source)
    at java.time.zone.ZoneRulesProvider.getRules(Unknown Source)
    at java.time.ZoneRegion.ofId(Unknown Source)
    at java.time.ZoneId.of(Unknown Source)
    at java.time.ZoneId.of(Unknown Source)
    at datetime.Java8DateTime.localDateAPI(Java8DateTime.java:173)
    at datetime.Java8DateTime.main(Java8DateTime.java:34)
100th day of 2014=2016-04-09
Year 2019 is Leap Year? false
Today is before 01/01/2017? false
Current Time=2019-05-16T11:50:59.619
20 days after today will be 2019-06-05
5 weeks after today will be 2019-06-20
30 months after today will be 2021-11-16
20 days before today will be 2019-04-26
5 weeks before today will be 2019-04-11
30 months before today will be 2016-11-16
First date of this month= 2019-05-01
Last date of this year= 2019-12-31
Period Format= P7M15D
Months remaining in the year= 7
*****************Local Date Time API*******************
Current DateTime=2019-05-16T11:50:59.620
Current DateTime=2019-05-16T11:50:59.620
Specific Date=2014-01-01T10:10:30
Current Date in IST=2019-05-16T11:50:59.620
10000th second time from 01/01/1970= 1970-01-01T02:46:40
*****************Local Time API*******************
Current Time=11:50:59.620
Specific Time of Day=12:20:25.000000040
Current Time in IST=11:50:59.620
10000th second time= 02:46:40
*********Set Date and Time Manually***************
Local Date :2012-12-12
Local Date :1970-05-31
Local Time :10:15:30
Local Time :13:18
*********Get Date and Time Values***************
Local Date :2019-05-16
Local Date time Format : 16/5/2019 11:50:59
*********Operation On LocalDate***************
Local Date :2018-02-14
Local Date :2020-08-18
*********Difference of On LocalDate***************
Days :4
Months :6
Years :2
Days :916
Months :30
Years :2

Above solutions are my search to perform all type of operations with date and time with java 8 API generally face while development. If you face other issue apart from it. Please mention in comments that will help with others.

[Solved] Date Format : java.text.ParseException: Unparseable date: “yyyy-MM-ddThh:mm:ss.SSSZ”


SimpleDateFormat throw java.text.ParseException exception when passing date for parsing not match with formatting pattern.

java.text.ParseException is runtime unchecked exception which signals that an error has been reached unexpectedly while parsing.

Constructors

  • ParseException (String message, int errorOffset) : Constrcut a ParseException with the specified detail message and offset. A detail message is a String that describes this particular exception. where errorOffset : is the position where error occurred.

Methods

  • public int getErrorOffset() :Returns the position where the error was found.

Example SimpleDateFormat throw ParseException

In this example currentFormat is matching with date passed in sourceDate that’s what failing with parse exception.

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;

public class ChangeDateFormat {

	public static void main(String[] args) {
		String targetFormat = "MM/DD/YYYY hh:mm:ss a";
		String currentFormat = "yyyy-MM-dd'T'hh:mm:ss'Z'";
		String sourceDate = "2019-02-12T11:29:10.761Z";
		System.out.println("Source Date :"+sourceDate);
		String timezone = "CDT";
		DateFormat srcDf = new SimpleDateFormat(currentFormat);
		srcDf.setTimeZone(TimeZone.getTimeZone(timezone));
		DateFormat destDf = new SimpleDateFormat(targetFormat);
		try {
			Date date = srcDf.parse(sourceDate);
			String targetDate = destDf.format(date);
			System.out.println("Target Date :"+targetDate);

		} catch (ParseException ex) {
			ex.printStackTrace();
		}

	}

}

Output:


Source Date :2019-02-12T11:29:10.761Z
java.text.ParseException: Unparseable date: "2019-02-12T11:29:10.761Z"
    at java.text.DateFormat.parse(Unknown Source)
    at com.fiot.test.ChangeDateFormat.main(ChangeDateFormat.java:21)

Solutions

To resolve this issue date format should be same as passing source date.

Correct Format for Date is yyyy-MM-dd’T’hh:mm.ss.SS’Z’

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;

public class ChangeDateFormat {

	public static void main(String[] args) {
		String targetFormat = "MM/DD/YYYY hh:mm:ss a";
		String currentFormat = "yyyy-MM-dd'T'hh:mm:ss.SSS'Z'";
		String sourceDate = "2019-02-12T11:29:10.761Z";
		System.out.println("Source Date :"+sourceDate);
		String timezone = "CDT";
		DateFormat srcDf = new SimpleDateFormat(currentFormat);
		srcDf.setTimeZone(TimeZone.getTimeZone(timezone));
		DateFormat destDf = new SimpleDateFormat(targetFormat);
		try {
			Date date = srcDf.parse(sourceDate);
			String targetDate = destDf.format(date);
			System.out.println("Target Date :"+targetDate);

		} catch (ParseException ex) {
			ex.printStackTrace();
		}

	}

}

Output:


Source Date :2019-02-12T11:29:10.761Z
java.text.ParseException: Unparseable date: "2019-02-12T11:29:10.761Z"
    at java.text.DateFormat.parse(Unknown Source)
    at com.fiot.test.ChangeDateFormat.main(ChangeDateFormat.java:21)

More Issues Solution

To solved Date Time same code , formatting  and issues solutions follow the link given below:

Java Date and Time Handling Tutorial

[Solved] Date Format : java.lang.IllegalArgumentException: Illegal pattern character ‘Z’ or ‘T’


SimpleDateFormat throw java.lang.IllegalArgumentException at runtime while parsing date format.

Follow link below to get in depth knowledge of IllegalArgumentException .

[Solved] java.lang.IllegalArgumentException: “ABC”

Example DateTime throwing IllegalArgumentexception

In this example target format is throwing IllegalArgumentException because of using illegal pattern character as Z and T.

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;

public class ChangeDateFormat {

	public static void main(String[] args) {
		String targetFormat = "MM/DD/YYYY hh:mm:ss a";
		String currentFormat = "yyyy-MM-ddThh:mm:ss.SSSZ";
		String sourceDate = "2019-02-12T11:29:10.761Z";
		System.out.println("Source Date :"+sourceDate);
		String timezone = "CDT";
		DateFormat srcDf = new SimpleDateFormat(currentFormat);
		srcDf.setTimeZone(TimeZone.getTimeZone(timezone));
		DateFormat destDf = new SimpleDateFormat(targetFormat);
		try {
			Date date = srcDf.parse(sourceDate);
			String targetDate = destDf.format(date);
			System.out.println("Target Date :"+targetDate);

		} catch (ParseException ex) {
			ex.printStackTrace();
		}

	}

}

Output :


Source Date :2019-02-12T11:29:10.761Z
Exception in thread "main" java.lang.IllegalArgumentException: Illegal pattern character 'T'
    at java.text.SimpleDateFormat.compile(Unknown Source)
    at java.text.SimpleDateFormat.initialize(Unknown Source)
    at java.text.SimpleDateFormat.(Unknown Source)
    at java.text.SimpleDateFormat.(Unknown Source)
    at com.fiot.test.ChangeDateFormat.main(ChangeDateFormat.java:17)

Solutions

SimpleDateFormat allow only some key characters only while using date time formatting. Here using characters Z and T for matching date time pattern in sourceDate that what throwing IllegalArgumentException . To resolve such issues for using  characters apart from formatting char in date format always use with ‘Z’ or ‘T’ (with single quote) as given below. Follow link to see complete list for formatting characters and date format.

Date Time Formatting Characters and Patterns

Correct Date Time Format
"yyyy-MM-dd'T'hh:mm:ss.SSS'Z'"

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;

public class ChangeDateFormat {

	public static void main(String[] args) {
		String targetFormat = "MM/DD/YYYY hh:mm:ss a";
		String currentFormat = "yyyy-MM-dd'T'hh:mm:ss.SSS'Z'";
		String sourceDate = "2019-02-12T11:29:10.761Z";
		System.out.println("Source Date :"+sourceDate);
		String timezone = "CDT";
		DateFormat srcDf = new SimpleDateFormat(currentFormat);
		srcDf.setTimeZone(TimeZone.getTimeZone(timezone));
		DateFormat destDf = new SimpleDateFormat(targetFormat);
		try {
			Date date = srcDf.parse(sourceDate);
			String targetDate = destDf.format(date);
			System.out.println("Target Date :"+targetDate);

		} catch (ParseException ex) {
			ex.printStackTrace();
		}

	}

}

Output:


Source Date :2019-02-12T11:29:10.761Z
Target Date :02/43/2019 04:59:10 PM

More Issues Solution

To solved Date Time same code , formatting  and issues solutions follow the link given below:

Java Date and Time Handling Tutorial

 

[Solved] Date Format AM/PM : java.lang.IllegalArgumentException: Illegal pattern character ‘A’


SimpleDateFormat throw java.lang.IllegalArgumentException at runtime while parsing date format.

Follow link below to get in depth knowledge of IllegalArgumentException .

[Solved] java.lang.IllegalArgumentException: “ABC”

Example DateTime throwing IllegalArgumentexception

In this example target format is throwing IllegalArgumentException because of using invalid formatting char for display AM/PM.

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;

public class ChangeDateFormat {

	public static void main(String[] args) {
		String targetFormat = "MM/DD/YYYY hh:mm:ss AM/PM";
		String currentFormat = "yyyy-MM-dd'T'hh:mm:ss.SSS'Z'";
		String sourceDate = "2019-02-12T11:29:10.761Z";
		System.out.println("Source Date :"+sourceDate);
		String timezone = "CDT";
		DateFormat srcDf = new SimpleDateFormat(currentFormat);
		srcDf.setTimeZone(TimeZone.getTimeZone(timezone));
		DateFormat destDf = new SimpleDateFormat(targetFormat);
		try {
			Date date = srcDf.parse(sourceDate);
			String targetDate = destDf.format(date);
			System.out.println("Target Date :"+targetDate);

		} catch (ParseException ex) {
			ex.printStackTrace();
		}

	}

}

Output:


Source Date :2019-02-12T11:29:10.761Z
Exception in thread "main" java.lang.IllegalArgumentException: Illegal pattern character 'A'
    at java.text.SimpleDateFormat.compile(Unknown Source)
    at java.text.SimpleDateFormat.initialize(Unknown Source)
    at java.text.SimpleDateFormat.(Unknown Source)
    at java.text.SimpleDateFormat.(Unknown Source)
    at com.fiot.test.ChangeDateFormat.main(ChangeDateFormat.java:19)

Solutions :

SimpleDateFormat allow only some key characters only while using date time formatting. Here for showing AM/PM should use character as as mentioned in below code in targetFormat. Follow link to see complete list for formatting characters and date format.

Date Time Formatting Characters and Patterns

Correct format to AM/PM
"MM/DD/YYYY hh:mm:ss a"

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;

public class ChangeDateFormat {

	public static void main(String[] args) {
		String targetFormat = "MM/DD/YYYY hh:mm:ss a";
		String currentFormat = "yyyy-MM-dd'T'hh:mm:ss.SSS'Z'";
		String sourceDate = "2019-02-12T11:29:10.761Z";
		System.out.println("Source Date :"+sourceDate);
		String timezone = "CDT";
		DateFormat srcDf = new SimpleDateFormat(currentFormat);
		srcDf.setTimeZone(TimeZone.getTimeZone(timezone));
		DateFormat destDf = new SimpleDateFormat(targetFormat);
		try {
			Date date = srcDf.parse(sourceDate);
			String targetDate = destDf.format(date);
			System.out.println("Target Date :"+targetDate);

		} catch (ParseException ex) {
			ex.printStackTrace();
		}

	}

}

Output:


Source Date :2019-02-12T11:29:10.761Z
Target Date :02/43/2019 04:59:10 PM

More Issues Solution

To solved Date Time same code , formatting  and issues solutions follow the link given below:

Java Date and Time Handling Tutorial

Java: Duration and Period Calculation


Almost every developer handle Duration and Period issues while need to do any calculation based on Date and Time. In Java 8 introduces new classes to handle Duration and period.

  • Period : A date period is measured in days, months, and years. Period can be calculated by java.time.Period class.
  • Duration: A time duration is measured in hours, minutes, and seconds. Duration can be calculated by java.time.Duration class.

Period period= Period.between(localDate1, localDate2);

Duration duration=Duration.between(localTime1, localTime2);

Duration.toString() method return duration as P1Y10M6D. Here duration is 1 year, 10 month and 6 days.

Period.toString() method return period as PT3H10M40S. Here duration is 3 hour, 10 minute and 40 seconds.

Example

Below is example to calculate Period and Duration  between two dates and times.

package com.date;

import java.time.Duration;
import java.time.LocalDate;
import java.time.LocalTime;
import java.time.Month;
import java.time.Period;
import java.time.format.DateTimeFormatter;
import java.time.temporal.ChronoUnit;

public class Java8DurationAndPeriodExample {

public static void main(String[] args) {

LocalDate june9th2016 = LocalDate.of(2016, Month.JUNE, 9);
LocalDate April15th2017 = LocalDate.of(2017, Month.APRIL, 15);
DateTimeFormatter format=DateTimeFormatter.ofPattern("MM/dd/yy");
// Compute period:
Period period=Period.between(April15th2017, june9th2016);
System.out.format("Period between %s and %s is %d year, %d month, %d days n" , April15th2017.format(format), june9th2016.format(format), period.getYears(), period.getMonths(), period.getDays());

// Add one month to August 10, 2018:
LocalDate April15th2017plusOneMonth=April15th2017.plus(1, ChronoUnit.MONTHS);
System.out.format("Adding one month to %s yields %s n", April15th2017.format(format), April15th2017plusOneMonth.format(format));

// Subtract one month from August 10, 2018:
LocalDate April15th2017minusOneMonth=April15th2017.plus(-1, ChronoUnit.MONTHS);
System.out.format("Subtracting one month from %s yields %s n", April15th2017.format(format), April15th2017minusOneMonth.format(format));

// Create two times for duration processing:
LocalTime twelveFifteenPM = LocalTime.of(12, 15, 9);
LocalTime twoTwentyFiveAM = LocalTime.of(2, 25, 0);
DateTimeFormatter timeFormat=DateTimeFormatter.ofPattern("HH:mm:ss a");
Duration duration=Duration.between(twoTwentyFiveAM, twelveFifteenPM);

System.out.format("Duration between %s and %s is %s n", twoTwentyFiveAM.format(timeFormat), twelveFifteenPM.format(timeFormat), duration);
duration=Duration.between(twelveFifteenPM, twoTwentyFiveAM);
System.out.format("Duration between %s and %s is %s n", twelveFifteenPM.format(timeFormat), twoTwentyFiveAM.format(timeFormat), duration);
	<span 				data-mce-type="bookmark" 				id="mce_SELREST_start" 				data-mce-style="overflow:hidden;line-height:0" 				style="overflow:hidden;line-height:0" 			></span>}
}

Output


Period between 04/15/17 and 06/09/16 is 0 year, -10 month, -6 days 
Adding one month to 04/15/17 yields 05/15/17 
Subtracting one month from 04/15/17 yields 03/15/17 
Duration between 02:25:00 AM and 12:15:09 PM is PT9H50M9S 
Duration between 12:15:09 PM and 02:25:00 AM is PT-9H-50M-9S 

[Solved] java.time.temporal. UnsupportedTemporalType Exception: Unsupported field: YearOfEra


UnsupportedTemporalTypeException is sub class of java.time.DateTimeException which is runtime checked exception. UnsupportedTemporalTypeException indicates that a ChronoField or ChronoUnit is not supported for a Temporal class.

Constructors

  • UnsupportedTemporalTypeException(String message): Constructs a new UnsupportedTemporalTypeException with the specified message.
  • UnsupportedTemporalTypeException(String message, Throwable cause): Constructs a new UnsupportedTemporalTypeException with the specified message and cause.

 

Exception Example

Below is example to convert Legacy date(java.util.Date) to java.time.Instant and vice versa.

package java.time.temporal;

import java.text.SimpleDateFormat;
import java.time.Instant;
import java.time.format.DateTimeFormatter;
import java.util.Date;

public class UnsupportedTemporalTypeExceptionExample {

public static void main(String[] args) {
SimpleDateFormat utilDateTimeFormat=new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
//Exception on below line to resolve this issue uncomment at end of line.
DateTimeFormatter java8DateTimeFormat=DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss");//.withZone(ZoneId.systemDefault());;
//Date to Instant
Date date=new Date();
Instant inst = date.toInstant();
System.out.println("Initial Date :"+utilDateTimeFormat.format(date));
System.out.println("Converted Instant :"+java8DateTimeFormat.format(inst));
//Instant To Date
Date newDate = Date.from(inst);
System.out.println("Converted Date :"+utilDateTimeFormat.format(newDate));
	}
}

Exception StackTrace


Initial Date :2018/08/04 08:11:53
Exception in thread "main" java.time.temporal.UnsupportedTemporalTypeException: Unsupported field: YearOfEra
    at java.time.Instant.getLong(Unknown Source)
    at java.time.format.DateTimePrintContext.getValue(Unknown Source)
    at java.time.format.DateTimeFormatterBuilder$NumberPrinterParser.format(Unknown Source)
    at java.time.format.DateTimeFormatterBuilder$CompositePrinterParser.format(Unknown Source)
    at java.time.format.DateTimeFormatter.formatTo(Unknown Source)
    at java.time.format.DateTimeFormatter.format(Unknown Source)
    at com.date.Legacy2Java8DateTimeInteroprability.main(Legacy2Java8DateTimeInteroprability.java:26)

Issue

The Instant class doesn’t contain Zone information, it only stores timestamp in milliseconds from UNIX epoch, i.e. 1 Jan 1070 from UTC. So, formatter can’t print a date because date always printed for concrete time zone. To format an Instant a time-zone is required. Without a time-zone, the formatter does not know how to convert the instant to human date-time fields, and therefore throws an exception.

Solutions

The time-zone can be added directly to the formatter using withZone().You should set time zone to formatter and all will be fine.

in above example you can uncomment commented section as below to solve this issue.


DateTimeFormatter java8DateTimeFormat=DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss").withZone(ZoneId.systemDefault());;

some more ways to format date


DateTimeFormatter formatter =
    DateTimeFormatter.ofLocalizedDateTime( FormatStyle.SHORT )
                     .withLocale( Locale.UK )
                     .withZone( ZoneId.systemDefault() );

or

DateTimeFormatter formatter = DateTimeFormatter.ofLocalizedDateTime(FormatStyle.SHORT).withLocale(Locale.UK).withZone(ZoneOffset.UTC);

Java: Legacy to Java 8 Date Time Interoperability


In Java 8 added some new methods with Legacy java.util Date and Time classes to convert object of java.time classes to get advantage new java 8 Date and Time classes with minimal changes.

Points To Remember:

  • java.util.Date and java.time.Instance classes are similar. The Date.from(Instant) and Date.toInstant() methods allow conversion between these classes. It represents instantaneous point of time in UTC which is independent of TimeZone  as epoch-seconds (since 1970-01-01T00:00:00Z) plus nanoseconds.
  • The java.time.ZonedDateTime class is the replacement for java.util.GregorianCalendar. The GregorianCalendar.from(ZonedDateTime) and GregorianCalendar.to(ZonedDateTime) methods faciliate conversions between these classes. It present time as follows:
    • LocalDate : year, month and day
    • LocalTime: hour, minute, second, nanoseconds
    • ZoneId: time zone
    • ZoneOffset: current offset from GMT
  • The ZoneOffset class specifies only an offset from Greenwich/UTC. The ZoneId class specifies a time zone identifier and has access to the rules used each time zone.
  • GeregorianCalendar with date as 1970-01-01 will use date component can be replaced with an instance of LocalDate.
  • GeregorianCalendar with time as 00:00 will use time component can be replaced with an instance of LocalTime.

java.util.Date to an java.time.Instant


Date date=new Date();
Instant instant=date.toInstant();

An java.time.Instant to java.util.Date


Date date=Date.from(instant);

java.util.Calendar to an java.time.Instant


Calendar cal=Calendar.getInstance();
Instant instant=cal.toInstant();

java.util.GregorianCalendar instance to an java.time.ZoneDateTime


Calendar gCal=GregorianCalendar.getInstance();
ZoneDateTime zoneDateTime=ZoneDateTime.ofInstant(gCal.toInstant(),ZoneId.systemDefault());

java.time.ZoneDateTime instance to java.util.GregorianCalendar


GregorianCalendar gCal=GregorianCalendar.from(zoneDateTime);

java.util.TimeZone object to java.time.ZoneId


Calendar gCal1=GregorianCalendar.getInstance();
TimeZone tz = cal.getTimeZone();
ZoneId zoneID=tz.toZoneId();
int tzoffset = cal.get(Calendar.ZONE_OFFSET);

Example

In below example considered all the cases of Legacy to Java 8 object classes.

package com.date;

import java.text.SimpleDateFormat;
import java.time.Instant;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.ZoneId;
import java.time.ZonedDateTime;
import java.time.format.DateTimeFormatter;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.TimeZone;

public class Legacy2Java8DateTimeInteroprability {

public static void main(String[] args) {
SimpleDateFormat utilDateTimeFormat=new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
DateTimeFormatter java8DateTimeFormat=DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss").withZone(ZoneId.systemDefault());;

//Date to Instant
Date date=new Date();
Instant inst = date.toInstant();
System.out.println("Initial Date :"+utilDateTimeFormat.format(date));
System.out.println("Converted Instant :"+java8DateTimeFormat.format(inst));

//Instant To Date
Date newDate = Date.from(inst);
System.out.println("Converted Date :"+utilDateTimeFormat.format(date));

//Calendar to ZoneDateTime
Calendar cal = Calendar.getInstance();
ZonedDateTime zdt = ZonedDateTime.ofInstant(cal.toInstant(), ZoneId.systemDefault());
System.out.println("Calendar to ZoneDateTime :"+java8DateTimeFormat.format(zdt));

//Calendar to Instant
Instant inst1 = cal.toInstant();
System.out.println("Calendar to Instant :"+java8DateTimeFormat.format(inst1));

//Geregorian calendar from Zone Date Time
GregorianCalendar gcal = GregorianCalendar.from(zdt);
System.out.println("Gregorian Calendar Date Time:"+utilDateTimeFormat.format(gcal.getTime()));
ZonedDateTime zdt1 = gcal.toZonedDateTime();
System.out.println("Calendar to ZoneDateTime Date :"+java8DateTimeFormat.format(zdt1));

LocalDateTime ldt = zdt1.toLocalDateTime();
System.out.println("Local Date Time :"+java8DateTimeFormat.format(ldt));
LocalDate localDate = zdt1.toLocalDate();
System.out.println("Local Date :"+java8DateTimeFormat.format(ldt));
LocalTime localTime = zdt1.toLocalTime();
System.out.println("Local Time :"+java8DateTimeFormat.format(ldt));

//TimeZone to Zone Id
Calendar gCal1=GregorianCalendar.getInstance();
TimeZone tz = cal.getTimeZone();
System.out.println("Time Zone :"+tz.getDisplayName());
ZoneId zoneID=tz.toZoneId();
System.out.println("Zone ID:"+zoneID.getId());
int tzoffset = cal.get(Calendar.ZONE_OFFSET);
<span 				data-mce-type="bookmark" 				id="mce_SELREST_start" 				data-mce-style="overflow:hidden;line-height:0" 				style="overflow:hidden;line-height:0" 			></span>System.out.println("Zone Offset:"+tzoffset);
	}
}

Output


Initial Date :2018/08/04 07:48:45
Converted Instant :2018/08/04 07:48:45
Converted Date :2018/08/04 07:48:45
Calendar to ZoneDateTime :2018/08/04 07:48:45
Calendar to Instant :2018/08/04 07:48:45
Gregorian Calendar Date Time:2018/08/04 07:48:45
Calendar to ZoneDateTime Date :2018/08/04 07:48:45
Local Date Time :2018/08/04 07:48:45
Local Date :2018/08/04 07:48:45
Local Time :2018/08/04 07:48:45
Time Zone :Pacific Standard Time
Zone ID:America/Los_Angeles
Zone Offset:-28800000

Java : How to get current date time?


In below example you will learn ways to get current date and time from Legacy Java Date and Calendar APIs and also from Java 8 LocalDateTime, LocalDate and LocalTime..

java.util.Date

Date date=new Date();

java.util.Calendar and java.util.GregorianCalendar

Calendar calendar=Calendar.getInstance();
Calendar gCalnedar=GregorianCalendar.getInstance();

java.time.LocaleDateTime

LocalDateTime localDateTime=LocalDateTime.now();

java.time.LocaleDate

LocalDate localDate=LocalDate.now();

java.time.LocaleTime

LocalTime localTime=LocalTime.now();

 

Complete Example

package com.date;

import java.text.SimpleDateFormat;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.format.DateTimeFormatter;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

public class CurrentDateandTimeExample {

public static void main(String[] args) {

SimpleDateFormat dateTimeFormat=new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");
//java.util.Date
Date date=new Date();
System.out.println("java.util.date Current Date and Time :"+ dateTimeFormat.format(date));

//java.util.Calendar and java.util.GregorianCalendar
Calendar calendar=Calendar.getInstance();
System.out.println("java.util.Calendar Current Date and Time :"+ dateTimeFormat.format(calendar.getTime()));
Calendar gCalendar=GregorianCalendar.getInstance();
System.out.println("java.util.GregorianCalendar Current Date and Time :"+ dateTimeFormat.format(gCalendar.getTime()));

//Java 8
//java.time.LocalDateTime
DateTimeFormatter dateTimeFormatter=DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss");
LocalDateTime lDateTime=LocalDateTime.now();
System.out.println("java.time.LocalDateTime Current Date and Time :"+ dateTimeFormatter.format(lDateTime));

//java.time.LocalDate
DateTimeFormatter dateFormatter=DateTimeFormatter.ofPattern("yyyy/MM/dd");
LocalDate lDate=LocalDate.now();
System.out.println("java.time.LocalDate Current :"+ dateFormatter.format(lDate));

//java.time.LocalTime
DateTimeFormatter timeFormatter=DateTimeFormatter.ofPattern("HH:mm:ss");
LocalTime lTime=LocalTime.now();
System.out.println("java.time.LocalTime Current Time :"+ timeFormatter.format(lTime));

	}

}

Output


java.util.date Current Date and Time :2018/08/03 12:12:26
java.util.Calendar Current Date and Time :2018/08/03 12:12:26
java.util.GregorianCalendar Current Date and Time :2018/08/03 12:12:26
java.time.LocalDateTime Current Date and Time :2018/08/03 12:12:26
java.time.LocalDate Current :2018/08/03
java.time.LocalTime Current Time :12:12:26

Java : System Time and Calculate Processing Time


System.currentTimeMillis(): Returns the current time in milliseconds. The granularity of the value depends on the underlying operating system and may be larger. For example, many operating systems measure time in units of tens of milliseconds.

System.nanoTime(): Returns the current value of the running Java Virtual Machine’s high-resolution time source, in nanoseconds. This method can only be used to measure elapsed time and is not related to any other notion of system or wall-clock time.

These methods are used to calculate processing time or performance of operations , methods and apis.

Processing Time = End Time – Start Time ;

Check below example to calculate processing time :

Example

public class SystemTimeCalculation {

public static void main(String[] args) {
long startTime=System.currentTimeMillis();
long nanoStartTime=System.nanoTime();
int i=0;
while(i++<1000000);
long endTime=System.currentTimeMillis();
long nanoEndTime=System.nanoTime();
System.out.println("System Calculate Time:"+(endTime-startTime));
System.out.println("System Calculate Nano Time:"+(nanoEndTime-nanoStartTime));

}

}

Output


System Calculate Time:2
System Calculate Nano Time:1888263

Java : Sort Date Time Object and Text Format


In Java classes java.util.Date, java.util.Calendar, java.time.LocalDateTime, java.time.LocalDate and java.time.LocalTime  implements comparable interface for natural ordering. We can sort these objects implements comparable interface as below


Collections.sort(List <Date> list);
Collections.sort(List <Calendar> list);
Collections.sort(List <LocalDateTime> list);
Collections.sort(List <LocalDate> list);
Collections.sort(List <LocalTime> list);

Problem occurred when date in String format and following different format pattern as MM/dd/yyyy ‘@’hh:mm a or some more patterns then you have to implement Comparator to sort this date text patterns as below


Collections.sort(dateStrList, new Comparator() {
DateFormat f = new SimpleDateFormat("MM/dd/yyyy '@'hh:mm a"); 

@Override public int compare(String o1, String o2) {
 try { 
   return f.parse(o1).compareTo(f.parse(o2)); 
} catch (ParseException e) { 
throw new IllegalArgumentException(e); 
} 
} }); 

To learn Comparator and Comparable check below link.

Java : Comparable Vs Comparator

In below example you will see sorting of date  in text format and objects also.

Example

package com.date;

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

public class SortingDateTime {
public static void main(String[] args) {
//java 8
sortDateTimeObject();
sortDateTimeText();
}

private static void sortDateTimeObject() {
List<LocalDateTime>dateTimeList=new ArrayList<LocalDateTime>();
dateTimeList.add(LocalDateTime.of(2012, 05, 12, 5, 16));
dateTimeList.add(LocalDateTime.of(2014, 03, 23, 11, 26));
dateTimeList.add(LocalDateTime.of(2011, 02, 13, 9, 36));
dateTimeList.add(LocalDateTime.of(2013, 11, 12, 5, 16));
dateTimeList.add(LocalDateTime.of(2017, 8, 11, 21, 26));
dateTimeList.add(LocalDateTime.of(2016, 9, 05, 19, 36));

DateTimeFormatter dateTimeFormatter = DateTimeFormatter
				.ofPattern("MM/dd/yyyy '@'hh:mm a");
System.out.println("---> Date & Time Object List Before Sort (MM/dd/yyyy '@'hh:mm a)");
for(LocalDateTime dateTime:dateTimeList)
{
System.out.println(dateTime.format(dateTimeFormatter));
}
// LocalDateTime  internally having Comparable interface no need additional Comparator
Collections.sort(dateTimeList);

System.out.println("---> Date & Time Object List After Sort (MM/dd/yyyy '@'hh:mm a)");
for(LocalDateTime dateTime:dateTimeList)
{
System.out.println(dateTime.format(dateTimeFormatter));
}

}

private static void sortDateTimeText()
{
List<String>dateStrList=new ArrayList<String>();
// MM/dd/yyyy '@'hh:mm a
dateStrList.add("01/21/2014 @03:13 PM");
dateStrList.add("01/21/2011 @04:37 PM");
dateStrList.add("01/21/2012 @10:41 AM");
dateStrList.add("01/21/2013 @10:48 AM");
dateStrList.add("01/22/2015 @06:16 AM");
dateStrList.add("01/22/2013 @06:19 AM");
dateStrList.add("01/21/2018 @05:19 PM");
dateStrList.add("01/21/2013 @05:19 PM");

System.out.println("---> Date & Time List Before Sort (MM/dd/yyyy '@'hh:mm a)");
for(String dateStr:dateStrList)
System.out.println(dateStr);

//Sort String Date
Collections.sort(dateStrList, new Comparator<String>() {
DateFormat f = new SimpleDateFormat("MM/dd/yyyy '@'hh:mm a");
@Override
public int compare(String o1, String o2) {
try {
  return f.parse(o1).compareTo(f.parse(o2));
    } catch (ParseException e) {
      throw new IllegalArgumentException(e);
    }
}
});

System.out.println("---> Date & Time List After Sort (MM/dd/yyyy '@'hh:mm a)");
for(String dateStr:dateStrList)
System.out.println(dateStr);
 }
}

Output


---> Date & Time Object List Before Sort (MM/dd/yyyy '@'hh:mm a)
05/12/2012 @05:16 AM
03/23/2014 @11:26 AM
02/13/2011 @09:36 AM
11/12/2013 @05:16 AM
08/11/2017 @09:26 PM
09/05/2016 @07:36 PM
---> Date & Time Object List After Sort (MM/dd/yyyy '@'hh:mm a)
02/13/2011 @09:36 AM
05/12/2012 @05:16 AM
11/12/2013 @05:16 AM
03/23/2014 @11:26 AM
09/05/2016 @07:36 PM
08/11/2017 @09:26 PM
---> Date & Time List Before Sort (MM/dd/yyyy '@'hh:mm a)
01/21/2014 @03:13 PM
01/21/2011 @04:37 PM
01/21/2012 @10:41 AM
01/21/2013 @10:48 AM
01/22/2015 @06:16 AM
01/22/2013 @06:19 AM
01/21/2018 @05:19 PM
01/21/2013 @05:19 PM
---> Date & Time List After Sort (MM/dd/yyyy '@'hh:mm a)
01/21/2011 @04:37 PM
01/21/2012 @10:41 AM
01/21/2013 @10:48 AM
01/21/2013 @05:19 PM
01/22/2013 @06:19 AM
01/21/2014 @03:13 PM
01/22/2015 @06:16 AM
01/21/2018 @05:19 PM

Java : Sort Date Object and Text Format


In Java classes java.util.Date, java.util.Calendar, java.time.LocalDateTime, java.time.LocalDate and java.time.LocalTime  implements comparable interface for natural ordering. We can sort these objects implements comparable interface as below


Collections.sort(List <Date> list);
Collections.sort(List <Calendar> list);
Collections.sort(List <LocalDateTime> list);
Collections.sort(List <LocalDate> list);
Collections.sort(List <LocalTime> list);

Problem occurred when date in String format and following different format pattern as dd/MM/yyyy or some more patterns then you have to implement Comparator to sort this date text patterns as below


Collections.sort(dateStrList, new Comparator() {
DateFormat f = new SimpleDateFormat("dd/MM/yyyy"); 

@Override public int compare(String o1, String o2) {
 try { 
   return f.parse(o1).compareTo(f.parse(o2)); 
} catch (ParseException e) { 
throw new IllegalArgumentException(e); 
} 
} }); 

To learn Comparator and Comparable check below link.

Java : Comparable Vs Comparator

In below example you will see sorting of date  in text format and objects also.

Example

package com.date;

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

public class SortingDate {

public static void main(String[] args) {
 //java 8
sortDateObject();
sortDateText();
}

private static void sortDateText() {
List<String>dateStrList=new ArrayList<String>();
// Date format dd/MM/YYYY
dateStrList.add("03/04/2016");
dateStrList.add("03/01/2016");
dateStrList.add("02/06/2016");
dateStrList.add("02/09/2016");
dateStrList.add("22/09/2016");
dateStrList.add("16/09/2016");
dateStrList.add("03/04/2016");
dateStrList.add("01/08/2017");
dateStrList.add("02/06/2017");
dateStrList.add("02/09/2014");
dateStrList.add("22/09/2018");
dateStrList.add("16/09/2015");

System.out.println("---> Date List Before Sort (dd/MM/yyyy)");
for(String dateStr:dateStrList)
System.out.println(dateStr);

//Sort String Date
Collections.sort(dateStrList, new Comparator<String>() {
DateFormat f = new SimpleDateFormat("dd/MM/yyyy");
    @Override
    public int compare(String o1, String o2) {
    try {
	 return f.parse(o1).compareTo(f.parse(o2));
	} catch (ParseException e) {
	       throw new IllegalArgumentException(e);
	   }
	   }
	});

    System.out.println("---> Date List After Sort (dd/MM/yyyy)");
    for(String dateStr:dateStrList)
    System.out.println(dateStr);

	}

private static void sortDateObject() {
List<LocalDate>dateList=new ArrayList<LocalDate>();
dateList.add(LocalDate.of(2012, 05, 12));
dateList.add(LocalDate.of(2014, 03, 23));
dateList.add(LocalDate.of(2011, 02, 13));
dateList.add(LocalDate.of(2013, 11, 12));
dateList.add(LocalDate.of(2017, 8, 11));
dateList.add(LocalDate.of(2016, 9, 05));

DateTimeFormatter dateTimeFormatter = DateTimeFormatter
				.ofPattern("MM/dd/yyyy");
System.out.println("---> Date  Object List Before Sort (MM/dd/yyyy)");
for(LocalDate localDate:dateList)
{
  System.out.println(localDate.format(dateTimeFormatter));
}
// LocalDate  internally having Comparable interface no need additional Comparator
Collections.sort(dateList);

System.out.println("---> Date Object List After Sort (MM/dd/yyyy)");
for(LocalDate localDate:dateList)
{
System.out.println(localDate.format(dateTimeFormatter));
}

}

}

Output


---> Date  Object List Before Sort (MM/dd/yyyy)
05/12/2012
03/23/2014
02/13/2011
11/12/2013
08/11/2017
09/05/2016
---> Date Object List After Sort (MM/dd/yyyy)
02/13/2011
05/12/2012
11/12/2013
03/23/2014
09/05/2016
08/11/2017
---> Date List Before Sort (dd/MM/yyyy)
03/04/2016
03/01/2016
02/06/2016
02/09/2016
22/09/2016
16/09/2016
03/04/2016
01/08/2017
02/06/2017
02/09/2014
22/09/2018
16/09/2015
---> Date List After Sort (dd/MM/yyyy)
02/09/2014
16/09/2015
03/01/2016
03/04/2016
03/04/2016
02/06/2016
02/09/2016
16/09/2016
22/09/2016
02/06/2017
01/08/2017
22/09/2018

Java: Date to GregorianCalendar and GregorianCalendar to Date Conversion


java.util.GregorianCalendar is a concrete subclass of GregorianCalendar this provides the standard calendar system used by most of the world. GregorianCalendarsupports Julian and Gregorian calendar systems with the support.

Gregorian calendar was instituted (October 15, 1582 in some countries, later in others). The cutover date may be changed by the caller by calling setGregorian

The only difference between the Gregorian and the Julian calendar is the leap year rule. The Julian calendar specifies leap years every four years, whereas the Gregorian calendar omits century years which are not divisible by 400.

GregorianCalendar getInstance method returns a Calendar object whose calendar fields have been initialized with the current date and time:

Calendar calendar= GregorianCalendar.getInstance();

In below example you will see conversion from Java Date object to Calendar and Calendar to Java Date.

Example

package com.date;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;

public class DateString2GregarianCalendarConversion {
private static final String MAIN_DATE="2012-02-16T18:30:00.000Z";
private static final String MAIN_DATE_FORMAT="yyyy-MM-dd'T'hh:mm:ss.SSS'Z'";
private static final String DATE_FORMAT1="yyyyMMdd";
public static void main(String[] args) {
SimpleDateFormat formatter=new SimpleDateFormat(MAIN_DATE_FORMAT);
try
{
Date date =formatter.parse(MAIN_DATE);
//convert date date to calendar
Calendar calendar=GregorianCalendar.getInstance();
calendar.setTime(date);
System.out.println(calendar);

//convert GregorianCalendar to date
Date newDate=calendar.getTime();
formatter=new SimpleDateFormat(DATE_FORMAT1);
System.out.println(formatter.format(newDate));

}
catch(ParseException ex)
{
ex.printStackTrace();
}
}
}

 

Output


java.util.GregorianCalendar[time=1329445800000,areFieldsSet=true,areAllFieldsSet=true,lenient=true,zone=sun.util.calendar.ZoneInfo[id="America/Los_Angeles",offset=-28800000,dstSavings=3600000,useDaylight=true,transitions=185,lastRule=java.util.SimpleTimeZone[id=America/Los_Angeles,offset=-28800000,dstSavings=3600000,useDaylight=true,startYear=0,startMode=3,startMonth=2,startDay=8,startDayOfWeek=1,startTime=7200000,startTimeMode=0,endMode=3,endMonth=10,endDay=1,endDayOfWeek=1,endTime=7200000,endTimeMode=0]],firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2012,MONTH=1,WEEK_OF_YEAR=7,WEEK_OF_MONTH=3,DAY_OF_MONTH=16,DAY_OF_YEAR=47,DAY_OF_WEEK=5,DAY_OF_WEEK_IN_MONTH=3,AM_PM=1,HOUR=6,HOUR_OF_DAY=18,MINUTE=30,SECOND=0,MILLISECOND=0,ZONE_OFFSET=-28800000,DST_OFFSET=0]
20120216

Reference

https://docs.oracle.com/javase/8/docs/api/java/util/GregorianCalendar.html

Java: Date to Calendar Conversion


The java.util.Calendar class that provides methods for converting between a specific instant in time and a set of calendar fields such as YEAR, MONTH, DAY_OF_MONTH, HOUR, and so on, and for manipulating the calendar fields, such as getting the date of the next month. An instant in time can be represented by a millisecond value that is an offset from the Epoch, January 1, 1970 00:00:00.000 GMT (Gregorian).

Calendar’s getInstance method returns a Calendar object whose calendar fields have been initialized with the current date and time:

Calendar calendar= Calendar.getInstance();

In below example you will see conversion from Java Date object to Calendar and Calendar to Java Date.

Example

package com.date;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

public class DateString2CalendarConversion {
private static final String MAIN_DATE="2012-02-16T18:30:00.000Z";
private static final String MAIN_DATE_FORMAT="yyyy-MM-dd'T'hh:mm:ss.SSS'Z'";
private static final String DATE_FORMAT1="yyyyMMdd";
public static void main(String[] args) {
SimpleDateFormat formatter=new SimpleDateFormat(MAIN_DATE_FORMAT);
try
{
Date date =formatter.parse(MAIN_DATE);
//convert date date to calendar
Calendar calendar=Calendar.getInstance();
calendar.setTime(date);
System.out.println(calendar);

//convert Calendar to date
Date newDate=calendar.getTime();
formatter=new SimpleDateFormat(DATE_FORMAT1);
System.out.println(formatter.format(newDate));

}
catch(ParseException ex)
{
 ex.printStackTrace();
}&lt;span 				data-mce-type="bookmark" 				id="mce_SELREST_start" 				data-mce-style="overflow:hidden;line-height:0" 				style="overflow:hidden;line-height:0" 			&gt;&lt;/span&gt;
}
}

Output


java.util.GregorianCalendar[time=1329445800000,areFieldsSet=true,areAllFieldsSet=true,lenient=true,zone=sun.util.calendar.ZoneInfo[id="America/Los_Angeles",offset=-28800000,dstSavings=3600000,useDaylight=true,transitions=185,lastRule=java.util.SimpleTimeZone[id=America/Los_Angeles,offset=-28800000,dstSavings=3600000,useDaylight=true,startYear=0,startMode=3,startMonth=2,startDay=8,startDayOfWeek=1,startTime=7200000,startTimeMode=0,endMode=3,endMonth=10,endDay=1,endDayOfWeek=1,endTime=7200000,endTimeMode=0]],firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2012,MONTH=1,WEEK_OF_YEAR=7,WEEK_OF_MONTH=3,DAY_OF_MONTH=16,DAY_OF_YEAR=47,DAY_OF_WEEK=5,DAY_OF_WEEK_IN_MONTH=3,AM_PM=1,HOUR=6,HOUR_OF_DAY=18,MINUTE=30,SECOND=0,MILLISECOND=0,ZONE_OFFSET=-28800000,DST_OFFSET=0]
20120216

Java : Date Format Locale and Internationalization


java.text.SimpleDateFormat class is subclass for java.text.DateFormat which use to convert String to Date and Date to different formatted String. DateFormat class supports TimeZone and Locale specific conversions also.

In below example you will see conversion of date to different Internationalization date by using Locale in SimpleDateFormat.

Example

package com.date;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Locale;
public class DateFormatLocaleAndInternationalization {

// Date formats
private static final String MAIN_DATE_FORMAT = "yyyy-MM-dd'T'hh:mm:ss.SSS'Z'";

public static void main(String[] args) {

Date date = new Date();
System.out.println("Date:" + date);

SimpleDateFormat formatter = new SimpleDateFormat(MAIN_DATE_FORMAT, Locale.CANADA);
System.out.println("CANADA DATE :" + formatter.format(date));

formatter = new SimpleDateFormat(MAIN_DATE_FORMAT, Locale.CANADA_FRENCH);
System.out.println("CANADA FRENCH DATE :" + formatter.format(date));

formatter = new SimpleDateFormat(MAIN_DATE_FORMAT, Locale.GERMANY);
System.out.println("GERMANY :" + formatter.format(date));

formatter = new SimpleDateFormat(MAIN_DATE_FORMAT, Locale.CHINESE);
System.out.println("CHINESE DATE :" + formatter.format(date));
formatter = new SimpleDateFormat(MAIN_DATE_FORMAT, Locale.ITALIAN);
System.out.println("ITALIAN :" + formatter.format(date));

formatter = new SimpleDateFormat(MAIN_DATE_FORMAT, Locale.TAIWAN);
System.out.println("TAIWAN DATE :" + formatter.format(date));

	}

}

Output


Date:Mon Jul 30 12:01:13 PDT 2018
CANADA DATE :2018-07-30T12:01:13.909Z
CANADA FRENCH DATE :2018-07-30T12:01:13.909Z
GERMANY :2018-07-30T12:01:13.909Z
CHINESE DATE :2018-07-30T12:01:13.909Z
ITALIAN :2018-07-30T12:01:13.909Z
TAIWAN DATE :2018-07-30T12:01:13.909Z

Java : java.util.Date and java.sql.Timestamp Conversion


java.sql.Timestamp is subclass of java.util.Date. java.sql.Timestamp  allows the JDBC API to identify this as an SQL TIMESTAMP value. It hold the SQL TIMESTAMP fractional seconds value, by allowing the specification of fractional seconds to a precision of nanoseconds. A Timestamp also provides formatting and parsing operations to support the JDBC escape syntax for timestamp values.
The precision of a Timestamp object is calculated to be either:
Precision 19 :yyyy-mm-dd hh:mm:ss
Precision 20 + s: yyyy-mm-dd hh:mm:ss.[fff…] and s represents the scale of the given Timestamp, its fractional seconds precision.

Note: This type is a composite of a java.util.Date and a separate nanoseconds value. Only integral seconds are stored in the java.util.Date component. The fractional seconds – the nanos – are separate.

Example

package com.date;

import java.sql.Timestamp;
import java.util.Date;

public class DateSQLTimestampConversion {

public static void main(String[] args) {
Date date = new Date();
System.out.println("Java Util Date : " + date);

// Converting java.util.Date to java.sql.Timestamp
Timestamp timestamp = new Timestamp(date.getTime());
System.out.println("Java SQL Timestamp : " + timestamp);

// Convert java.sql.Timestamp to java.util.Date
Date newDate = new Date(timestamp.getTime());
System.out.println("Java Util Date : " + date);
}

}

Output


Java Util Date : Mon Jul 30 11:35:27 PDT 2018
Java SQL Timestamp : 2018-07-30 11:35:27.246
Java Util Date : Mon Jul 30 11:35:27 PDT 2018

Reference

https://docs.oracle.com/javase/8/docs/api/java/sql/Timestamp.html

Java : java.util.Date and java.sql.Date Conversion


java.sql.Date a thin wrapper around a millisecond value that allows JDBC to identify this as an SQL DATE around. A milliseconds value represents the number of milliseconds that have passed since January 1, 1970 00:00:00.000 GMT (epoch). java.sql.Date instance normalized by settings hours, minute, seconds and milliseconds to zero.

Note: java.sql.Date have only Date part no any time related values.

Example

package com.date;

import java.util.Date;

public class DateSQLConversion {

public static void main(String[] args) {
java.util.Date utilDate = new java.util.Date();
System.out.println("Java Util Date : " + utilDate);

// contains only date information without time
java.sql.Date sqlDate = new java.sql.Date(utilDate.getTime());
System.out.println("Java SQL Date : " + sqlDate); 

//convert sql date to java date
java.util.Date newUtilDate=new Date(sqlDate.getTime());
System.out.println("Java Util Date : " + newUtilDate);
}

}

Output


Java Util Date : Mon Jul 30 11:06:20 PDT 2018
Java SQL Date : 2018-07-30
Java Util Date : Mon Jul 30 11:06:20 PDT 2018

Java : Date Format Conversion


In below example for Date format conversion. Here are characters use for date format design.

[table id=6 /]

 Example

package com.date;

import java.text.SimpleDateFormat;
import java.util.Date;

public class DateFormatChange {

public static String LEGACY_FORMAT = "EEE MMM dd hh:mm:ss zzz yyyy";
public static String ISO_FORMAT = "yyyy-MM-dd'T'HH:mm:ss.SSS zzz";
public static String SHORT_DATE = "yyyy-MM-dd";
private static final String MAIN_DATE_FORMAT = "yyyy-MM-dd'T'hh:mm:ss.SSS'Z'";
private static final String DATE_FORMAT1 = "yyyyMMdd";
private static final String DATE_FORMAT2 = "yyyy/MM/dd";

private static final SimpleDateFormat legacyFormatter = new SimpleDateFormat(LEGACY_FORMAT);
private static final SimpleDateFormat isoFormatter = new SimpleDateFormat(ISO_FORMAT);
private static final SimpleDateFormat shortFormatter = new SimpleDateFormat(SHORT_DATE);

public static void main(String[] args) {
Date date = new Date();
System.out.println("Default Date Format:" + date);
System.out.println("Legacy Date Format:" + legacyFormatter.format(date));
System.out.println("ISO Date Format:" + isoFormatter.format(date));
System.out.println("Short Date Format:" + shortFormatter.format(date));
// Other Date Format
SimpleDateFormat formatter = new SimpleDateFormat(DATE_FORMAT1);
System.out.println("Short Date Format1:" + formatter.format(date));
formatter = new SimpleDateFormat(DATE_FORMAT2);
System.out.println("Short Date Format2:" + formatter.format(date));
formatter = new SimpleDateFormat(MAIN_DATE_FORMAT);
System.out.println("Main Date Format:" + formatter.format(date));
	}
}

Output


Default Date Format:Sat Jul 28 13:35:28 PDT 2018
Legacy Date Format:Sat Jul 28 01:35:28 PDT 2018
ISO Date Format:2018-07-28T13:35:28.245 PDT
Short Date Format:2018-07-28
Short Date Format1:20180728
Short Date Format2:2018/07/28
Main Date Format:2018-07-28T01:35:28.245Z

Date pattern Examples

[table id=7 /]

Java : Date Format and TimeZone Conversion


In below example convert date to different date format and time zone.

Example

package com.date;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;

public class Date2TimeZoneUtility {
public static String LEGACY_FORMAT = "EEE MMM dd hh:mm:ss zzz yyyy";
public static String ISO_FORMAT = "yyyy-MM-dd'T'HH:mm:ss.SSS zzz";
public static String SHORT_DATE = "yyyy-MM-dd";
private static final TimeZone utc = TimeZone.getTimeZone("UTC");
private static final SimpleDateFormat legacyFormatter = new SimpleDateFormat(LEGACY_FORMAT);
private static final SimpleDateFormat isoFormatter = new SimpleDateFormat(ISO_FORMAT);
private static final SimpleDateFormat shortFormatter = new SimpleDateFormat(SHORT_DATE);
static {
		legacyFormatter.setTimeZone(utc);
		isoFormatter.setTimeZone(utc);
	}

public static void main(String[] args) {
Date2TimeZoneUtility dateUtility = new Date2TimeZoneUtility();
Date date = new Date();
System.out.println("Current Date Default:" + date);
System.out.println("--->Change Date Format");
// Legacy Date Format
System.out.println("Current Date Legacy Format:" + dateUtility.toString(date, legacyFormatter));
// ISO Date Format
System.out.println("Current Date ISO Format:" + dateUtility.toString(date, isoFormatter));
// Short Date Format
System.out.println("Current Date Short Format:" + dateUtility.toString(date, shortFormatter));
System.out.println("--->Change Date Format with Time Zone UTC");
// Legacy Date Format UTC TimeZone
System.out.println("Current Date Legacy Format:" + dateUtility.toLegacyFormat(date));
// ISO Date Format UTC TimeZone
System.out.println("Current Date ISO Format:" + dateUtility.toISOFormat(date));
// Short Date Format UTC TimeZone
System.out.println("Current Date Short Format:" + dateUtility.toShortFormat(date));
System.out.println("--->Change Date Format with different Time Zone");
// Legacy Date Format with time Zone EST
System.out.println("Current Date Legacy Format with TimeZone EST:"
				+ dateUtility.toStringWithTimeZone(date, legacyFormatter, "EST"));
// ISO Date Format with time zone IST
System.out.println( "Current Date ISO Format with TimeZone IST:" + dateUtility.toStringWithTimeZone(date, isoFormatter, "IST"));
// Short Date Format Short Date with PST
System.out.println("Current Date Short Format with TimeZone PST:"
				+ dateUtility.toStringWithTimeZone(date, shortFormatter, "PST"));
}

public String toString(final Date date, SimpleDateFormat dateformat) {
		return dateformat.format(date);
}

public String toStringWithTimeZone(final Date date, SimpleDateFormat dateformat, final String timezone) {
		final TimeZone tz = TimeZone.getTimeZone(timezone);
		dateformat.setTimeZone(tz);
		return dateformat.format(date);
}

public String toLegacyFormat(final Date date) {
		return legacyFormatter.format(date);
}

public String toISOFormat(final Date date) {
		return isoFormatter.format(date);
}

public String toShortFormat(final Date date) {
		return shortFormatter.format(date);
}

}

Output


Current Date Default:Sat Jul 28 12:58:38 PDT 2018
--->Change Date Format
Current Date Legacy Format:Sat Jul 28 07:58:38 UTC 2018
Current Date ISO Format:2018-07-28T19:58:38.932 UTC
Current Date Short Format:2018-07-28
--->Change Date Format with Time Zone UTC
Current Date Legacy Format:Sat Jul 28 07:58:38 UTC 2018
Current Date ISO Format:2018-07-28T19:58:38.932 UTC
Current Date Short Format:2018-07-28
--->Change Date Format with different Time Zone
Current Date Legacy Format with TimeZone EST:Sat Jul 28 02:58:38 EST 2018
Current Date ISO Format with TimeZone IST:2018-07-29T01:28:38.932 IST
Current Date Short Format with TimeZone PST:2018-07-28

[Solved] java.time.DateTimeException: Invalid value for NanoOfSecond (valid values 0 – 999999999): -1


java.time.DateTimeException occurs while calculating Date and Time in java.time classes. This exception is used to indicate problems with creating, querying and manipulating date-time objects.

Constructors

  • DateTimeException(String message) : Constructs a new date-time exception with the specified message.
  • DateTimeException(String message, Throwable cause) : Constructs a new date-time exception with the specified message and cause.

Sample Code

 try {
// Try creating time by providing invalid inputs
LocalTime invalidTime = LocalTime.of(12, 12, 23,-1);
// Exception in thread "main" java.time.DateTimeException:
// Invalid value for nano seconds valid values(0 - 999999999): -1
} catch (DateTimeException ex) {
ex.printStackTrace();
}
 

Output Message


Exception in thread "main" java.time.DateTimeException: Invalid value for NanoOfSecond (valid values 0 - 999999999): -1
    at java.time.temporal.ValueRange.checkValidValue(Unknown Source)
    at java.time.temporal.ChronoField.checkValidValue(Unknown Source)
    at java.time.LocalTime.of(Unknown Source)
    at datetime.Java8DateTime.main(Java8DateTime.java:69)

Issue

Here with throw DateTimeException if pass as Invalidate Date and Time. For above example passing hour as 24 which causing this issue because allowed values for hours is between range 0-23.

Solutions

To solve this issue pass hour value in method as between range 0-23. Below are some methods for LocalTime.of() and corresponding values range for each parameters.

  • LocalTime localTime= LocalTime.of(int hour, int minute) : Obtains an instance of LocalTime from an hour and minute.
  • LocalTime localTime= LocalTime.of(int hour, int minute, int second): Obtains an instance of LocalTime from an hour, minute and second.
  • LocalTime localTime= LocalTime.of(int hour, int minute, int second, int nanoOfSecond): Obtains an instance of LocalTime from an hour, minute, second and nanosecond.

Date and Time Allowed range:

  • Month : 0-12
  • Day : 

1-31 : (January, March, May, July, August, October, December)

1-28/29 : (February) Leap year have 29 days in February and Non leap year have 28 days

1-30: (April, June, September, November)

  • Hour: 0-23
  • Minute: 0-59
  • Second : 0 – 59
  • NanoSecond: 0 – 999999999

Issues Solution

For more other JAVA/JDBC issues solution follow link JAVA/JDBC Issues.