Book Image

The Java Workshop

By : David Cuartielles, Andreas Göransson, Eric Foster-Johnson
4 (2)
Book Image

The Java Workshop

4 (2)
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)

Summary

This chapter introduced unit testing. Testing is good and you want to write tests for all your Java code. If you write successful tests, then you can feel confident your code was written correctly.

JUnit provides the most popular testing framework for writing Java unit tests, though there are other frameworks you can try as well. The @Test annotation on a method tells JUnit that the given code is considered a test. JUnit will execute the test and see whether it succeeds. The JUnit assertions class contains a few static methods that you can use to verify the test results.

A parameterized test is a test into which you pass a few parameters. This is very useful when writing tests for code that you want to ensure can handle a variety of inputs. Mocking is a technique where you mock out external dependencies so that a unit test can concentrate on testing just one class.