Chapter 17

Introduction to Contexts and Dependency Injection for the Java^TM EE Platform

Contexts and Dependency Injection for the Java EE Platform (CDI) is one of several Java EE 6 features that help to knit together the web tier and the transactional tier of the Java EE platform. It is a set of services that, used together, makes it easy for developers to use enterprise beans along with JavaServer^TM Faces technology in web applications. Designed for use with stateful objects, it also has many broader uses, allowing developers a great deal of flexibility to integrate different kinds of components in a loosely coupled but type-safe way.

CDI is specified by JSR-299, which was formerly known as Web Beans. Related specifications that CDI uses include the following:

• JSR-330, Dependency Injection for Java

• The Managed Beans specification that is an offshoot of the Java EE 6 platform specification (JSR-316)

This chapter covers the following topics.

• Overview of Contexts and Dependency Injection for the Java EE Platform

• About Beans

• Beans as Injectable Objects

• Using Qualifiers

• Injecting Beans

• Using Scopes

• Giving Beans EL Names

• Adding Setter and Getter Methods

• Using a Managed Bean in a Facelets Page

• Injecting Objects by Using Producer Methods

• Configuring a CDI Application

• Further Information