Spring Boot

488 Pages·2017·10.49 MB·English

Mastering Spring 5.0
A comprehensive guide to becoming an expert in the Spring
Framework
This book is based on Spring Version 5.0 RC1
Ranga Rao Karanam
BIRMINGHAM - MUMBAI
Mastering Spring 5.0
Copyright © 2017 Packt Publishing
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First published: June 2017
Production reference: 1240617
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ISBN 978-1-78712-317-5
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Credits
Author Copy Editor
Ranga Rao Karanam Stuti Srivastava
Reviewer Project Coordinator
Jarosław Krochmalski Prajakta Naik
Commissioning Editor Proofreader
Kunal Parikh Safis Editing
Acquisition Editor Indexer
Denim Pinto Rekha Nair
Content Development Editor Graphics
Siddhi Chavan Abhinash Sahu
Technical Editor Production Coordinator
Supriya Thabe Shraddha Falebhai
About the Author
Ranga Rao Karanam is a programmer, trainer, and architect. His areas of interest include
Cloud Native Applications, microservices, evolutionary design, high-quality code, DevOps,
BDD, TDD, and refactoring. He loves consulting for start-ups on developing scalable,
component-based Cloud Native applications, and following modern development practices
such as BDD, continuous delivery, and DevOps. He loves the freedom the Spring
Framework brings to developing enterprise Java applications.
Ranga started in28minutes with the vision of creating high-quality courses on developing
Cloud Native Java applications. He is looking forward to enhancing his already
considerable success--75,000 students on Udemy and 35,000 subscribers on YouTube.
Ranga likes to play cricket and go hiking. His dream is to spend a year hiking the
Himalayas.
My family and best friends – thank you for everything!
About the Reviewer
Jarosław Krochmalski is a passionate software designer and developer who specializes in
the financial business domain. He has over 12 years of experience in software development.
He is a clean-code and software craftsmanship enthusiast. He is a Certified ScrumMaster
and a fan of Agile. His professional interests include new technologies in web application
development, design patterns, enterprise architecture, and integration patterns. He likes to
experiment with NoSQL and cloud computing. Jaroslaw has been working with IDEA since
its first release and has observed the IDE grow and mature. He has been designing and
developing software professionally since 2000 and has been using Java as his primary
programming language since 2002. In the past, he worked for companies such as Kredyt
Bank (KBC) and Bank BPS on many large-scale projects, such as international money orders,
express payments, and collection systems. He currently works as a consultant for the
Danish company 7N as an infrastructure architect for the Nykredit bank. You can reach him
via Twitter at @jkroch or by email at [email protected].
He has authored the books, IntelliJ Idea Essentials, Developing with Docker, and Docker and
Kubernetes for Java Developers by Packt, and he has reviewed another book by Packt, Spring
Essentials.
Hello to all my friends in Finsys, 7N, and Nykredit – keep up the good work!
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Table of Contents
Preface
1
Chapter 1: Evolution to Spring Framework 5.0
7
Spring Framework 8
Problems with EJB 8
Why is Spring Framework popular? 8
Simplified unit testing 9
Reduction in plumbing code 9
How does Spring Framework do this magic? 10
Architectural flexibility 11
Keep up with changing times 12
Spring modules 12
Spring Core Container 13
Cross-cutting concerns 13
Web 14
Business 14
Data 15
Spring Projects 15
Spring Boot 16
Spring Cloud 16
Spring Data 16
Spring Batch 17
Spring Security 18
Spring HATEOAS 18
New features in Spring Framework 5.0 19
Baseline upgrades 19
JDK 9 runtime compatibility 20
Usage of JDK 8 features in Spring Framework code 20
Reactive programming support 21
Functional web framework 21
Java modularity with Jigsaw 22
Kotlin support 23
Dropped features 24
Spring Boot 2.0 new features 25
Summary 26
Chapter 2: Dependency Injection
27
Understanding dependency injection 28
Understanding dependencies 28
The Spring IoC container 31
Defining beans and wiring 31
Creating a Spring IoC container 33
Java configuration for the application context 33
A quick review 34
Launching the application context with Java configuration 35
The console log 36
The XML configuration for the application context 37
Defining the XML Spring configuration 37
Launching an application context with the XML configuration 38
Writing JUnit using the Spring context 38
Unit testing with mocks 40
Container managed beans 42
Dependency injection types 43
The setter injection 43
The constructor injection 44
Constructor versus setter injection 44
Spring bean scopes 44
Java versus XML configuration 45
The @Autowired annotation in depth 46
The @Primary annotation 46
The @Qualifier annotation 47
Other important Spring annotations 47
Exploring Contexts and dependency injection 48
An example of CDI 49
Summary 50
Chapter 3: Building a Web Application with Spring MVC
51
Java web application architecture 52
Model 1 architecture 52
Model 2 architecture 53
Model 2 Front Controller architecture 54
Basic flows 55
Basic setup 55
Adding dependency for Spring MVC 55
Adding DispatcherServlet to web.xml 56
Creating Spring context 57
Flow 1 - Simple controller flow without View 57
Creating a Spring MVC controller 58
Running the web application 58
[ ii ]