Gson: Enjoy JSON (De-)Serialization in Java (eBook & Workbook)
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Gson: Enjoy JSON (De-)Serialization in Java

About the Book

Learn Every Detail About Gson

Every modern Java application will need to do some Java-JSON parsing in their application life cycle. Gson is the most commonly used library to do the Java-JSON serialization and deserialization automatically.

Data parsing and mapping is complex. Even though Gson makes things quite simple, there are a lot of details that can trip your development up. If it's crazy data structures, weird variable names or complex dynamic data, you can lose a lot of time on something that should be done in minutes. Gson solves most problems in just a few lines. You just need to know the solutions!

This book includes an extensive introduction to Gson's features. We recommend to read it before you even have to use Gson for the first time. But even if you're already an avid user of Gson and stuck at a problem, we're confident we'll solve your problem.

Use our extensive bundle to learn about:

  • Introduction to JSON & JSON-Java mapping
  • Quick start to jump right into Gson
  • Mapping of any Java type
  • Deep dive into Gson's configuration options
  • Practical examples of Gson customization
  • Even advanced topics (Streaming, Generics, ...) are covered
  • Necessary ProGuard configuration for Android app releases

Additionally, you'll get an extensive appendix:

  • Combining a customized Gson with Retrofit 2
  • Overview over common mistakes
  • Exploration of Gson alternatives

Who Is This Book For?

This book is for Android or Java developers who want to get a substantial overview and reference book for Gson. You’ll benefit from the clearly recognizable code examples in regard to your daily work with Gson.


If you’re just starting out with Gson (or coming from any other Java-JSON library like Jackson databind) this book will show you all important parts on how to work with Gson. The provided code snippets let you jumpstart and create the first mapping within minutes.


You already worked with Gson before? You’ll profit from our extensive code snippets and can improve your existing code base. Additionally, the book illustrates various optimizations for an even better performance.

Code Samples

Every code snippet in the book has been tested. We provide our test project as a leanpub extra. Feel free to download it and check the full code base as you move through the book. We try to keep the code snippets in the book as short as possible. If more context is necessary, the code examples should provide it.


For the first time, we provide additional separated resources besides our book. The workbook gives you a chance to implement everything you'll learn in this book yourself. In our experience actually using a library like Gson helps to reinforce the newly gained knowledge. Thus, we've designed the workbook, which gives you a guided playground to experiment and learn the features of Gson.

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    • Java
    • Android
    • JavaScript
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About the Author

Future Studio
Norman Peitek

Norman is passionate Android developer since 2011. He's developed multiple apps, which have been used by millions of users overall. Building high-quality products is always Norman's #1 focus. While working as an Android freelancer and consultant is his day job, he loves teaching and passing on knowledge on the side.

Since 2014, Norman started working on the API side as well. Developing node.js apps is a good alternative and provides some good insight into becoming a better programmer overall.

Norman has a Master's degree from the Otto von Guericke University Magdeburg.

Feel free to get in touch on twitter @peitek or LinkedIn.


eBook & Workbook


  • extras
    Gson Sample Code

    Code snippets of the book in action as an Android project.

  • PDF

  • EPUB

  • WEB

  • English

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Suggested price
Just The eBook


  • extras
    Gson Sample Code

    Code snippets of the book in action as an Android project.

  • PDF

  • EPUB

  • WEB

  • English

Minimum price
Suggested price

Bundles that include this book

Bought separately
Bundle Price
Bought separately
Bundle Price

About the Contributors

Christian Fellner
Christian Fellner

Christian is an experienced Software Engineer and consultant working with a wide variety of companies, ranging from startups to Fortune 500 companies.

His experiences range across a number of fields and technologies, including web and game development, virtual reality and machine learning.

Christian is an all-round nerd, passionate about outstanding design and creating innovational user experiences.

He has given training to many developers and students since 2011; explaining state of the art technologies and project management methodologies.

Christian has a BSc degree in Computer Systems in Engineering from the Otto von Guericke University Magdeburg.

Find him on Twitter: @celsiusF.

Marcus Pöhls
Marcus Pöhls

Marcus is an enthusiastic Android & Java developer. He’s developed multiple production-ready client and server applications. While following the core principle of performance for client apps, he also builds REST+JSON APIs that focus on clear and consistent design.

Besides his day job, sharing knowledge and teaching others has become a characteristic he never wants to miss.

Marcus has a Master’s degree in computer science from the Otto von Guericke University Magdeburg.

Feel free to get in touch on Twitter @marcuspoehls.

Table of Contents

  • About the Book
    • What Topics Are Covered in This Book?
    • Who Is This Book For?
    • Code Examples
    • Workbook
  • Chapter 1 — Introduction to Java-JSON Mapping
    • Adding Gson as Dependency
    • Basics of Java-JSON Serialization
    • Basics of Java-JSON Deserialization
  • Chapter 2 — JSON Mapping with Gson
    • Mapping of Nested Objects
    • Mapping of Arrays and Lists of Objects
    • Mapping of Maps
    • Mapping of Sets
    • Mapping of Null Values
  • Chapter 3 — Gson Model Annotations
    • How to Ignore Fields
    • How to Adjust the Naming of Fields
    • Multiple Deserialization Names with @SerializedName
  • Chapter 4 — Configuring Gson with GsonBuilder
    • GsonBuilder Basics
    • Naming Policies
    • Force Serialization of null Values
    • Go Beyond transient and @Expose with Exclusion Strategies
    • Relax Gson with Lenient
    • Special Values of Floats/Doubles
    • Model Versioning
    • Formatting of Dates & Custom Date/Time Mapping
    • Pretty Printing
    • HTML Escaping
  • Chapter 5 — Advanced Gson Usage
    • Mapping of Enums
    • Mapping of Circular References
    • Mapping of Generics
    • Custom Serialization for Simplification (Part 1)
    • Changing the Default Serialization with Custom Serialization (Part 2)
    • Custom Deserialization Basics
    • Custom Instance Creator
    • Customizing (De)Serialization via @JsonAdapter
    • Custom Deserialization for Calculated Fields
    • On-The-Fly-Parsing With Streams
  • Chapter 6 — ProGuard Configuration
    • Gson and ProGuard Are Not Best Friends
    • Standard Gson Configuration
  • Chapter 7 — Practical Gson
    • Low Level Parsing
    • Storing Data in Android’s SharedPreferences With Gson
    • How to Deserialize a List of Polymorphic Objects
  • Chapter 8 — Appendix
    • Gson’s Configuration for Retrofit 2
    • 5 Common Mistakes & Issues
    • Overview of Alternatives
  • Outro
    • Workbook
  • Future Studio Books
    • Retrofit
    • Picasso
    • Glide
    • Future Studio Bundle

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