Book Image

The Java Workshop

By : David Cuartielles, Andreas Göransson, Eric Foster-Johnson
Book Image

The Java Workshop

By: David Cuartielles, Andreas Göransson, Eric Foster-Johnson

Overview of this book

Java is a versatile, popular programming language used across a wide range of industries. Learning how to write effective Java code can take your career to the next level, and The Java Workshop will help you do just that. This book is designed to take the pain out of Java coding and teach you everything you need to know to be productive in building real-world software. The Workshop starts by showing you how to use classes, methods, and the built-in Collections API to manipulate data structures effortlessly. You’ll dive right into learning about object-oriented programming by creating classes and interfaces and making use of inheritance and polymorphism. After learning how to handle exceptions, you’ll study the modules, packages, and libraries that help you organize your code. As you progress, you’ll discover how to connect to external databases and web servers, work with regular expressions, and write unit tests to validate your code. You’ll also be introduced to functional programming and see how to implement it using lambda functions. By the end of this Workshop, you’ll be well-versed with key Java concepts and have the knowledge and confidence to tackle your own ambitious projects with Java.
Table of Contents (20 chapters)

Intermediate Operations

A stream can take any number of intermediate operations following the creation of the stream. An intermediate operation is often a filter or mapping of some type, but there are other types as well. Every intermediate operation returns another stream; that way, you can chain any number of intermediate operations to your pipeline.

The order of intermediate operations is very important as the stream returned from an operation will only reference the remaining or required elements of the previous stream.

There are several different types of intermediate operations. The following is an explanation of each of them:

  • filter: As the name suggests, this intermediate operation will return a subset of elements from the stream. It uses a predicate when applying the matching pattern, which is a functional interface that returns a Boolean. The easiest and most common way to implement this is using a lambda function:
    Stream.of(1, 2, 3, 4, 5, 6)
       ...