Testing in Java

This book is a comprehensive guide to software testing in Java, designed for both novice developers and experienced engineers looking to deepen their knowledge in test automation. Unlike many textbooks that only superficially touch on the topic, this edition offers a systematic approach to creating reliable and maintainable tests.

The reader will learn how to write unit tests using JUnit 5 and TestNG, master mock-testing techniques with Mockito and PowerMock, and learn how to integrate tests into a CI/CD process using Jenkins and Maven. Special attention is given to functional testing of web applications with Selenium WebDriver, including working with the Page Object Model and test framework design patterns.

The book consists of 12 chapters covering: the basics of unit testing, parameterized tests, test doubles, TDD (Test-Driven Development), database integration testing, REST API testing with RestAssured, load testing with JMeter, as well as practical advice on writing readable and stable tests. Each chapter provides real code examples ready to be used in projects of any complexity.

Why should you read this book? Because quality testing is not a luxury, but a necessity for any serious Java project. The author shares not only theoretical knowledge but also proven practical methodologies that will help reduce the number of bugs, speed up regression testing, and increase confidence in the code. You will learn to avoid common mistakes when writing tests, discover how to properly organize test architecture, and integrate automation into existing development processes.

The book will be useful for Java developers from Junior to Senior level, QA engineers transitioning to automation, as well as technical leads responsible for product quality. After reading, you will be able to independently set up a testing environment, write effective unit and integration tests, implement TDD practices, and create full-fledged test automation frameworks.