Book Image

Learn Java with Projects

By : Dr. Seán Kennedy, Maaike van Putten
5 (3)
Book Image

Learn Java with Projects

5 (3)
By: Dr. Seán Kennedy, Maaike van Putten

Overview of this book

Learn Java with Projects stands out in the world of Java guides; while some books skim the surface and others get lost in too much detail, this one finds a nice middle ground. You’ll begin by exploring the fundamentals of Java, from its primitive data types through to loops and arrays. Next, you’ll move on to object-oriented programming (OOP), where you’ll get to grips with key topics such as classes, objects, encapsulation, inheritance, polymorphism, interfaces, and more. The chapters are designed in a way that focuses on topics that really matter in real-life work situations. No extra fluff here, so that you get more time to spend on the basics and form a solid foundation. As you make progress, you’ll learn advanced topics including generics, collections, lambda expressions, streams and concurrency. This book doesn't just talk about theory—it shows you how things work with little projects, which eventually add up to one big project that brings it all together. By the end of this Java book, you’ll have sound practical knowledge of Java and a helpful guide to walk you through the important parts of Java.
Table of Contents (22 chapters)
1
Part 1: Java Fundamentals
9
Part 2: Object-Oriented Programming
15
Part 3: Advanced Topics

Examining intermediate operations

As we know, a stream pipeline consists of a source, followed by zero or more intermediate operations, followed by a terminal operation. While the terminal operation is mandatory, intermediate operations are not. That said, intermediate operations are where pipelines get their real power as they transform the stream data as it flows by. Unlike terminal operations, intermediate operations produce a stream as a result. Let us start with filter(), which is taken from IntermediateOperations.java on the repo:

filter(Predicate)

The filter() operation returns a stream containing the elements matching the given predicate. Figure 16.1 presents a code example (from IntermediateOperations.java on the repo):

Figure 16.1 - The filter(Predicate) intermediate operation in code

Figure 16.1 - The filter(Predicate) intermediate operation in code

In this figure, the countries whose names are longer than 5 characters are output.

distinct()

The distinct() operation returns a stream with duplicate...