Expanding the Understanding of Managed Beans in Java EE 6
The Java EE 6 specification encompasses a wide array of annotations for handling managed beans, including:
- @javax.annotation.ManagedBean
- @javax.inject.Named
- @javax.faces.ManagedBean
Navigating the Spectrum of Managed Beans
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JSF Managed Beans: Offered by the JavaServer Faces (JSF) specification, these beans support bean creation and dependency injection for JSF pages. They provide limited features compared to CDI beans and should be phased out in favor of the latter.
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CDI Beans: Introduced with CDI, these beans offer advanced capabilities such as interceptors, event handling, and dependency injection with qualifiers. They represent the primary managed bean mechanism in Java EE 6 and beyond.
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EJB: Enterprise JavaBeans (EJBs) are a fundamental concept in Java EE, providing transactional, distributed, and stateful/stateless services. They offer features unavailable to CDI beans, such as passivation and timers.
Injection Best Practices
Injection of managed beans can be achieved through the following annotations:
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@Inject: For injection into CDI beans and EJBs
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@EJB: Specifically for injecting EJBs into other managed beans
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@ManagedProperty: An older annotation still supported in Java EE 6, but recommended to use @Inject instead.
Selecting the Optimal Managed Bean Type
The decision of which managed bean type to use depends on the specific requirements of the application:
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CDI Beans: The default choice for general-purpose managed beans, offering a wide range of features and flexibility.
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EJBs: Essential for features such as transaction management, passivation, and timers.
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