// Before Java 8 button.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e) { System.out.println("Button clicked"); } }); // With Java 8 Lambda button.addActionListener(e -> System.out.println("Button clicked")); A powerful API for processing sequences of data using functional-style operations. Streams enable parallel processing with minimal effort.
// Lambda + Stream API + Method Reference double averageSalary = employees.stream() .filter(e -> Period.between(e.hireDate(), LocalDate.now()).getYears() >= 3) .mapToDouble(Employee::salary) .average() .orElse(0.0); java se development kit 8
// Optional usage Optional<String> longestTenured = employees.stream() .min(Comparator.comparing(Employee::hireDate)) .map(Employee::name); // Before Java 8 button
List<String> names = Arrays.asList("Alice", "Bob", "Charlie", "David"); // Filter, transform, and collect in one pipeline List<String> longNames = names.stream() .filter(name -> name.length() > 4) .map(String::toUpperCase) .collect(Collectors.toList()); // Result: ["CHARLIE", "DAVID"] A complete overhaul of date/time handling, replacing the notoriously flawed java.util.Date and Calendar classes. Inspired by Joda-Time, it is immutable, thread-safe, and intuitive. Inspired by Joda-Time, it is immutable, thread-safe, and
System.out.printf("Average salary (3+ years tenure): %.2f%n", averageSalary);
For new projects, Java 17 or 21 LTS are generally recommended. However, understanding JDK 8 remains essential for maintaining, modernizing, and understanding the vast number of systems that continue to run on this remarkable platform. Whether you're a veteran Java developer or just starting your journey, mastering JDK 8 is an investment that will pay dividends for years to come.