DateTime & Locale in Java

Introduction

Date – Time

LocalDate

• LocalDate.now()
• LocalDate.of(2021,12,21)
• LocalDate.parse(“2021-12-21”)
• localDate.plusWeeks(1)
• localDate.withYear(2021)

LocalTime

• LocalTime.now()
• LocalTime.of(9,5,23)
• LocalTime.parse(“13:23:23”)
• localTime.minus(3, ChronoUnit.MINUTES)

LocalDateTime

• LocalDateTime.now()
• LocalDateTime.parse(“2017-08-21 10:19”, DateTimeFormatter.ofPattern(“yyyy-MM-dd HH:mm”))
• LocalDateTime.of(date, time)
• localDateTime.plusDays(2)
• localDateTime.plusHours(2)
• localDate.plus(Duration.ofMinutes(5))

ZonedDateTime

• ZonedDateTime.now()
• ZonedDateTime.of(localDateTime, ZoneId.of(zoneString))
• ZonedDateTime.parse(“2021-05-05T10:12:23+05:30”)
• ZonedDateTime.of(2021, 12, 8, 12, 32, 55, 0, ZonedId.of(“US/Central”) )
• zonedDateTime.toInstant()
• zonedDateTime.with(TemporalAdjusters.next(DayOfWeek.THURSDAY))
• zonedDateTime.withZoneSameInstant(ZoneId.of(“US/Central”))
• zonedDateTime1.isBefore(zonedDateTime2)

ZonedId

• ZoneId.of(“US/Pacific”)
• ZonedId.getAvailableZoneIds()
• zoneId.getRules()
• zonedId.getRules().isDaylightSavings(instant)

Periods

• Period.ofMonths(1)
• zonedDateTime.minus(period)

Durations

• Duration.ofMinutes(ChronoUnit.MINUTES.between(localtime1, localtime2))
• localTime.plus(duration)

Instants

Instant is the number of seconds and nanoseconds since January 1, 1970(Java epoch)

• Instant.now()
• zonedDateTime.toInstant()

Locale

• Locale(“it”)
• Locale(“it”, “CH”)
• zonedDateTime.format(DateTimeFormater.ofLocalizedDateTime(FormatStyle.LONG).withLocale(Locale.JAPAN))

Properties

Used to Store Configuration settings and operating parameters for your application.

package come.jones.time;

import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.Properties;

public class CustomProperties {

	public static void main(String[] args) {
		Properties prop = new Properties();
		try {
			FileInputStream fileInputStream = new FileInputStream("src/prop1.properties");
			prop.load(fileInputStream);
			prop.setProperty("prop3", "value3");
			prop.list(System.out);
			FileOutputStream fileOutputStream = new FileOutputStream("prop2.properties");
			prop.store(fileOutputStream, "Adding prop3");
			fileInputStream.close();
			fileOutputStream.close();
			System.out.println("End");
		} catch (Exception e) {
		}
	}
}

Resource Bundles

Resource Bundles are helpful in providing language and country specific strings for display. When property files are used as resource bundles, then these files must end in “.properties”, and start with Locale, For Ex: MyApp_in_en.properties, MyApp_fr.properties.

ResourceBundle.getBundle(“APP”, new Locale(“en”, “CA”))

Choosing the correct properties file follows this Order.

• RB_en_CA.java/ properties –exactly what we need
• RB_en.java/properties –atleast language
• RB_hi_IN.java/properties — default Locale
• RB_hi.java/properties –atleast default language
• RB.java –atleast –atleast default Bundle