Java in Action

The book "Java in Action" is a practical guide to modern Java development, designed for programmers who are already familiar with the basics of syntax and want to deepen their knowledge, master advanced language features, and learn to write efficient, maintainable code.

The book covers key topics: lambda expressions, streams (Stream API), working with collections, multithreading, functional programming in Java, as well as approaches to testing and refactoring. Special attention is paid to practical examples and real-world usage scenarios, allowing the reader to immediately apply the acquired knowledge in projects.

Chapter contents:
1. Introduction to modern Java (Java 8–17)
2. Lambda expressions and functional interfaces
3. Stream API: data processing in a functional style
4. Working with optional values (Optional)
5. Parallel streams and multithreading
6. Collections: from classics to modern approaches
7. Design patterns in Java 8+
8. Testing with JUnit 5 and Mockito
9. Refactoring and code improvement
10. Integration with databases and external APIs

Who this book is for: for Junior and Mid-level Java developers who want to master modern language features, as well as for those transitioning from other languages (e.g., C# or Python) to Java and wanting to understand its idioms.

What the reader will learn: how to write concise and safe code using lambdas and streams, how to work effectively with multithreading, how to apply functional approaches in an object-oriented language, how to refactor legacy code, and how to build reliable tests.

Why you should read it: the book is written in accessible language, contains many code examples and practical exercises. It is not overloaded with theory but focuses on what a developer really needs in daily work. "Java in Action" is a bridge from a basic understanding of Java to professional mastery of the language.