Book Image

JBoss Weld CDI for Java Platform

By : Kenneth Finnigan
Book Image

JBoss Weld CDI for Java Platform

By: Kenneth Finnigan

Overview of this book

CDI simplifies dependency injection for modern application developers by taking advantage of Java annotations and moving away from complex XML, while at the same time providing an extensible and powerful programming model. "JBoss Weld CDI for Java Platform" is a practical guide to CDI's dependency injection concepts using clear and easy-to-follow examples. This will help you take advantage of the power behind CDI, as well as providing a firm understanding of how to use it within your applications. "JBoss Weld CDI for Java Platform" covers all the major aspects of CDI, breaking it down into understandable pieces. This book will take you through many examples of how these concepts can be utilized, helping you get up and running quickly and painlessly. "JBoss Weld CDI for Java Platform" gives you an insight into the different scopes provided by CDI and the use cases for which each has been designed. You will learn everything about dependency injection, scopes, events, producers, and more from JBoss Weld CDI, as well as how producers can create new beans for consumption within your application. You will also learn how to build a real world application with CDI using JSF and AngularJS for different web interfaces.
Table of Contents (17 chapters)
JBoss Weld CDI for Java Platform
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Built-in scopes


The term built-in scope refers to the scope annotations that are defined by the CDI specification and implemented by Weld for us to use in our applications. They represent the most common scope use cases that are present within web application development in a servlet container. If it didn't provide these scope annotations for us, it would be extremely inefficient and error prone for us to implement our own solutions for these scopes.

The CDI specification defines the following built-in scopes, some of which we've already used in the previous chapters:

  • @RequestScoped

  • @SessionScoped

  • @ApplicationScoped

  • @ConversationScoped

@RequestScoped , @SessionScoped , and @ApplicationScoped are all applicable to any web application that we develop, and they are accessible from any servlet request within our application.

@ConversationScoped is specifically targeted for use with a JSF request by the CDI specification, though it is possible to implement support for other web frameworks...