Java Duration API Guide

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Introduction

The Duration class in Java 8, part of the java.time package, represents a time-based amount of time, such as '34.5 seconds'. It can be used to measure time intervals in nanoseconds and seconds. The Duration class is immutable and thread-safe, making it a robust choice for handling time intervals in applications.

Key Points:

• Immutability: Immutable and thread-safe.
• Precision: Can represent durations down to nanoseconds.
• Arithmetic Operations: Supports addition, subtraction, and other arithmetic operations.
• Compatibility: Can be used with other Java 8 date and time classes.

Table of Contents

1. Creating a Duration
2. Methods of Duration Class
3. Comparing Durations
4. Manipulating Durations
5. Converting Durations
6. Using Duration with Date-Time APIs
7. Examples
8. Conclusion

1. Creating a Duration

Using of Methods

The Duration class provides various of methods to create durations of different time units.

Duration duration1 = Duration.ofDays(1); // 1 day Duration duration2 = Duration.ofHours(2); // 2 hours Duration duration3 = Duration.ofMinutes(30); // 30 minutes Duration duration4 = Duration.ofSeconds(45); // 45 seconds Duration duration5 = Duration.ofMillis(500); // 500 milliseconds Duration duration6 = Duration.ofNanos(1000000); // 1 millisecond in nanoseconds 

Using between

Creates a duration between two Temporal objects (e.g., two Instant objects).

Instant start = Instant.now(); Instant end = start.plus(Duration.ofHours(1)); Duration duration = Duration.between(start, end); System.out.println("Duration between start and end: " + duration); 

2.() Methods of Duration Class

getSeconds()

Returns the number of seconds in the duration.

long seconds = duration.getSeconds(); System.out.println("Seconds: " + seconds); 

getNano()

Returns the nanoseconds part of the duration.

int nanos = duration.getNano(); System.out.println("Nanoseconds: " + nanos); 

toDays()

Converts the duration to days.

long days = duration.toDays(); System.out.println("Days: " + days); 

toHours()

Converts the duration to hours.

long hours = duration.toHours(); System.out.println("Hours: " + hours); 

toMinutes()

Converts the duration to minutes.

long minutes = duration.toMinutes(); System.out.println("Minutes: " + minutes); 

toMillis()

Converts the duration to milliseconds.

long millis = duration.toMillis(); System.out.println("Milliseconds: " + millis); 

toNanos()

Converts the duration to nanoseconds.

long nanos = duration.toNanos(); System.out.println("Nanoseconds: " + nanos); 

3. Comparing Durations

isZero()

Checks if the duration is zero.

boolean isZero = duration.isZero(); System.out.println("Is duration zero? " + isZero); 

isNegative()

Checks if the duration is negative.

boolean isNegative = duration.isNegative(); System.out.println("Is duration negative? " + isNegative); 

compareTo()

Compares this duration to another duration.

Duration duration1 = Duration.ofMinutes(5); Duration duration2 = Duration.ofMinutes(10); int comparison = duration1.compareTo(duration2); System.out.println("Comparison: " + comparison); // -1, 0, or 1 

4. Manipulating Durations

plus()

Adds the specified duration to this duration.

Duration longerDuration = duration.plus(Duration.ofMinutes(10)); System.out.println("Longer Duration: " + longerDuration); 

minus()

Subtracts the specified duration from this duration.

Duration shorterDuration = duration.minus(Duration.ofMinutes(10)); System.out.println("Shorter Duration: " + shorterDuration); 

multipliedBy()

Multiplies this duration by the specified value.

Duration multipliedDuration = duration.multipliedBy(2); System.out.println("Multiplied Duration: " + multipliedDuration); 

dividedBy()

Divides this duration by the specified value.

Duration dividedDuration = duration.dividedBy(2); System.out.println("Divided Duration: " + dividedDuration); 

5. Converting Durations

toString()

Converts the duration to an ISO-8601 string representation.

String durationString = duration.toString(); System.out.println("Duration as String: " + durationString); 

parse()

Parses an ISO-8601 string representation to create a duration.

Duration parsedDuration = Duration.parse("PT1H30M"); // 1 hour and 30 minutes System.out.println("Parsed Duration: " + parsedDuration); 

6. Using Duration with Date-Time APIs

Adding and Subtracting Duration to Instant

Instant now = Instant.now(); Instant later = now.plus(Duration.ofHours(1)); Instant earlier = now.minus(Duration.ofHours(1)); System.out.println("Now: " + now); System.out.println("One hour later: " + later); System.out.println("One hour earlier: " + earlier); 

Using Duration with ChronoUnit

Duration duration = Duration.of(1, ChronoUnit.HOURS); System.out.println("Duration in Hours: " + duration); 

7. Examples

Example 1: Creating a Duration

Duration duration = Duration.ofMinutes(90); System.out.println("Duration: " + duration); 

Example 2: Comparing Durations

Duration duration1 = Duration.ofMinutes(30); Duration duration2 = Duration.ofMinutes(60); System.out.println("Is duration1 zero? " + duration1.isZero()); System.out.println("Is duration1 negative? " + duration1.isNegative()); System.out.println("Comparison: " + duration1.compareTo(duration2)); 

Example 3: Manipulating Durations

Duration duration = Duration.ofMinutes(30); Duration longerDuration = duration.plus(Duration.ofMinutes(10)); Duration shorterDuration = duration.minus(Duration.ofMinutes(10)); System.out.println("Longer Duration: " + longerDuration); System.out.println("Shorter Duration: " + shorterDuration); 

Example 4: Converting Duration to Other Units

Duration duration = Duration.ofMinutes(90); long hours = duration.toHours(); long minutes = duration.toMinutes(); long millis = duration.toMillis(); System.out.println("Hours: " + hours); System.out.println("Minutes: " + minutes); System.out.println("Milliseconds: " + millis); 

Example 5: Using Duration with Instant

Instant now = Instant.now(); Duration duration = Duration.ofHours(1); Instant later = now.plus(duration); Instant earlier = now.minus(duration); System.out.println("Now: " + now); System.out.println("One hour later: " + later); System.out.println("One hour earlier: " + earlier); 

8. Conclusion

The Duration class in Java 8 provides a powerful and flexible way to work with time-based amounts of time. Its immutability, precision, and easy interoperability with other date-time classes make it a valuable tool for handling time intervals in Java applications.

Summary of Key Points:

• Immutability: Immutable and thread-safe.
• Precision: Can represent durations down to nanoseconds.
• Arithmetic Operations: Supports addition, subtraction, multiplication, and division.
• Interoperability: Easily converts to and from other date-time types.

By understanding and utilizing the Duration class effectively, you can manage time intervals in your Java applications with precision and reliability.