Java8 Programming Examples

Discover the Quarter of a given Date in JAva

java8

import java.time.LocalDate;
import java.util.Calendar;
import java.util.Locale;
public class Demo {
	public static void main(String[] args) {
		LocalDate currentDate = LocalDate.now();
		System.out.println("Current Date = "+currentDate);
		Calendar cal = Calendar.getInstance(Locale.US);
		int month = cal.get(Calendar.MONTH);
		int quarter = (month / 3) + 1;
		System.out.println("Quarter = "+quarter);
	}
}

Java Program to get Temporal Queries precision

java8

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.time.Year;
import java.time.YearMonth;
import java.time.temporal.TemporalQueries;
import java.time.temporal.TemporalQuery;
import java.time.temporal.TemporalUnit;
public class Demo {
	public static void main(String[] args) {
		TemporalQuery<TemporalUnit>precision = TemporalQueries.precision();
		System.out.println("TemporalQueries precision...");
		System.out.println(LocalDate.now().query(precision));
		System.out.println(LocalTime.now().query(precision));
		System.out.println(LocalDateTime.now().query(precision));
		System.out.println(YearMonth.now().query(precision));
		System.out.println(Year.now().query(precision));
	}
}

Java Program to get the seconds since the beginning

java8

import java.time.Instant;
import java.time.temporal.ChronoUnit;
public class Demo {
	public static void main(String[] args) {
		long seconds = Instant.ofEpochSecond(0L).until(Instant.now(), ChronoUnit.SECONDS);
		System.out.println("Seconds since the beginning of the Java epoch = "+seconds);
	}
}

Java Program to get day of week as string

java8

import java.time.DayOfWeek;
import java.time.LocalDate;
public class Demo {
	public static void main(String[] args) {
		LocalDate currentDate = LocalDate.now();
		System.out.println("Current Date = "+currentDate);
		DayOfWeek day = currentDate.getDayOfWeek();
		int weekVal = day.getValue();
		String weekName = day.name();
		System.out.println("Week Number = "+weekVal);
		System.out.println("Week Name = "+weekName);
	}
}

Java Program to get timezone id strings

java8

import java.time.ZoneId;
public class Demo {
	public static void main(String[] args) {
		System.out.println("TimeZones in the US");
		ZoneId.getAvailableZoneIds().stream().filter(s ->s.startsWith("America"))
		.forEach(System.out::println);
	}
}

Java Program to get milliseconds between dates

java8

import java.time.LocalDateTime;
import static java.time.temporal.ChronoUnit.MILLIS;
public class Demo {
	public static void main(String[] argv) {
		LocalDateTime dateOne = LocalDateTime.now();
		LocalDateTime dateTwo = LocalDateTime.of(2019, 4, 10, 11, 20);
		System.out.printf("Date One = "+dateOne);
		System.out.printf("\nDate Two = "+dateTwo);
		long res = MILLIS.between(dateOne, dateTwo);
		System.out.println("\nMilliseconds between two dates = " + res);
	}
}

Java Program to check if two dates are equal

java8

import java.time.LocalDate;
public class Demo {
	public static void main(String[] argv) {
		LocalDate dateOne = LocalDate.now();
		LocalDate dateTwo = LocalDate.of(dateOne.getYear(), dateOne.getMonth(), dateOne.getDayOfMonth());
		System.out.printf("Date One = "+dateOne);
		System.out.printf("\nDate Two = "+dateTwo);
		if (dateOne.equals(dateTwo)) {
			System.out.printf("\nBoth the dates are same!", dateOne, dateTwo);
		}
	}
}

Java Program to get the value stored in a byte as an unsigned integer

java8

public class Demo {
	public static void main(String[] args) {
		byte signedVal = -100;
		int unsignedVal = Byte.toUnsignedInt(signedVal);
		System.out.println("Signed value (byte) = " + signedVal);
		System.out.println("Unsigned value (byte) = " + unsignedVal);
	}
}

Java Program to generate n distinct random numbers

java8

import java.util.LinkedHashSet;
import java.util.Random;
import java.util.Set;
public class Demo {
	public static void main(final String[] args) throws Exception {
		Random randNum = new Random();
		Set<Integer>set = new LinkedHashSet<Integer>();
		while (set.size() < 10) {
			set.add(randNum.nextInt(10)+1);
		}
		System.out.println("Distinct random numbers = "+set);
	}
}

Fill array values in Java

java8

import java.util.Arrays;
public class Demo {
	public static void main(String[] args) {
		int[] arr = new int[10];
		System.out.println("Array = "+Arrays.toString(arr));
		Arrays.fill(arr, 2, 7, 100);
		System.out.println("Fill = "+Arrays.toString(arr));
	}
}

Follow

Newsletter