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

Injection point metadata


There is lots of useful metadata information that is present on an injection point, which is represented in the javax.enterprise.inject.spi.InjectionPoint interface. Weld provides an implementation of InjectionPoint with @Dependent scope and @Default qualifier for us to retrieve the metadata.

The injection point provides the following functions:

  • getBean(): This returns the Bean object of the bean defined on the injection point

  • getType(): This returns the bean type of the injection point

  • getQualifiers(): This returns all the qualifiers of the injection point

  • getMember(): This returns a different instance depending on whether the injection point utilizes field injection (Field), method parameter injection (Method), or constructor parameter injection (Constructor)

  • getAnnotated(): This returns AnnotatedField for field injection or AnnotatedParameter for method and constructor parameter injection

When we have an @Dependent scoped bean, there are occasions when it needs...