Book Image

Hands-On Design Patterns with Java

By : Dr. Edward Lavieri
2 (1)
Book Image

Hands-On Design Patterns with Java

2 (1)
By: Dr. Edward Lavieri

Overview of this book

Java design patterns are reusable and proven solutions to software design problems. This book covers over 60 battle-tested design patterns used by developers to create functional, reusable, and flexible software. Hands-On Design Patterns with Java starts with an introduction to the Unified Modeling Language (UML), and delves into class and object diagrams with the help of detailed examples. You'll study concepts and approaches to object-oriented programming (OOP) and OOP design patterns to build robust applications. As you advance, you'll explore the categories of GOF design patterns, such as behavioral, creational, and structural, that help you improve code readability and enable large-scale reuse of software. You’ll also discover how to work effectively with microservices and serverless architectures by using cloud design patterns, each of which is thoroughly explained and accompanied by real-world programming solutions. By the end of the book, you’ll be able to speed up your software development process using the right design patterns, and you’ll be comfortable working on scalable and maintainable projects of any size.
Table of Contents (15 chapters)
Free Chapter
Section 1: Introducing Design Patterns
Section 2: Original Design Patterns
Section 3: New Design Patterns

Understanding the publisher-subscriber design pattern

The publisher-subscriber design pattern establishes two entities: a publisher that sends messages based on events and a subscriber that subscribes to those events. With this design pattern, publishers transmit messages and subscribers listen for them and then take the appropriate action or inaction.

As illustrated next, the Publisher publishes events. The Subscribers subscribe to the events. Once an event is heard, the Subscriber provides the computation or processing as appropriate for the event:

Publisher-subscriber design patternoverview

This design pattern is event-driven and can be implemented by using the event-driven architecture, the observer pattern, and the message broker pattern, covered in previous chapters of this book.

This section provided a brief overview of the publisher-subscriber design pattern.