Java 8 FAQ: Top Questions

Java 8 introduced a brand-new java.time package that offers a modern, immutable, and more readable approach to date and time management. It replaces the older java.util.Date and java.util.Calendar classes which were error-prone and mutable.

🗺️ Step-by-Step Instructions:

1. Use LocalDate for date only, LocalTime for time only, and LocalDateTime for both.
2. Use Period for date-based time differences and Duration for time-based differences.
3. Use DateTimeFormatter for parsing and formatting.

📥 Example Input:

LocalDate date = LocalDate.of(2023, 6, 21);
LocalDate today = LocalDate.now();
Period period = Period.between(date, today);

🏆 Expected Output:

P1Y (or similar output depending on current date)

✅ Java 8 Solution:

import java.time.LocalDate;
import java.time.Period;

public class DateExample {
  public static void main(String[] args) {
    LocalDate past = LocalDate.of(2023, 6, 21);
    LocalDate today = LocalDate.now();

    Period gap = Period.between(past, today);
    System.out.println("Period between: " + gap);
  }
}

📘 Detailed Explanation:

• Immutable: All classes in java.time are immutable and thread-safe.
• Fluent API: Allows chaining methods in a clean and readable format.
• Better parsing/formatting: Uses DateTimeFormatter for locale-friendly output.

🛠️ Use Cases:

• Replacing legacy Date and Calendar in new applications.
• Handling birthday calculations, age, or date ranges safely.
• Formatting dates for UI or APIs in a locale-sensitive way.