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

Mapping streams

Again, there are many new functional interfaces to be aware of; and again, thankfully, they follow a consistent naming pattern. Table 16.4 outlines the more common ones.

Table 16.4 - Mapping streams

Table 16.4 - Mapping streams

In this table, the rows represent the source stream class and the columns represent the target stream class. Again, we use color to help organize our explanations. The yellow boxes represent situations where the source and target classes are the same. So, for example, if you are going from a DoubleStream to another DoubleStream, the method is map(DoubleUnaryOperator). The functional method is also listed - so for this example, DoubleUnaryOperator‘s functional method is double applyAsDouble(double).

Let us examine the brown boxes. Each of these uses a mapToObj() method as the source is a primitive stream and the target is a stream of objects. The source stream hints at the function to be used. For example, if the source is a DoubleStream...