Java 8 Features Tutorial

Java 8 introduced a lot of new features that made the language more powerful and easier to use. This tutorial will cover some of the most important features of Java 8.

1. Lambda Expressions

Lambda expressions provide a concise way to represent an instance of an anonymous class. They are often used with functional interfaces, which are interfaces with a single abstract method.

List<String> list = Arrays.asList("a1", "a2", "b1", "c2", "c1");

list.sort((String s1, String s2) -> s1.compareTo(s2));

2. Stream API

The Stream API provides a high-level abstraction for processing collections of objects. It allows you to perform operations on collections in a declarative way.

List<String> list = Arrays.asList("a1", "a2", "b1", "c2", "c1");

list.stream()
    .filter(s -> s.startsWith("c"))
    .forEach(System.out::println);

3. Date and Time API

Java 8 introduced a new Date and Time API that provides a more intuitive and flexible way to work with dates and times.

LocalDate date = LocalDate.of(2014, Month.DECEMBER, 31);

4. Optional Class

The Optional class is used to represent the absence of a value. It helps to avoid the NullPointerException that is common in Java code.

Optional<String> name = Optional.ofNullable(null);
name.orElse("John Doe");

5. New Built-in Methods

Java 8 added many new built-in methods to the collections framework, such as map, filter, and reduce.

List<Integer> numbers = Arrays.asList(1, 2, 3, 4);
int sum = numbers.stream().reduce(0, Integer::sum);

For more information on Java 8 features, you can read our detailed Java 8 Features Guide.

Java 8 Features