TOTD #49: Converting a JSF 1.2 application to JSF 2.0 - @ManagedBean

This is a follow up to TOTD #48 which showed how to convert a JSF 1.2 application to use new features of JSF 2.0. In this blog, we'll talk about a new annotation added to the JSF 2.0 specification - @ManagedBean.

@ManagedBean is a new annotation in the JSF 2.0 specification. The javadocs (bundled with the nightly) clearly defines the purpose of this annotation:

The presence of this annotation on a class automatically registers the class with the runtime as a managed bean class. Classes must be scanned for the presence of this annotation at application startup, before any requests have been serviced.

Essentially this is an alternative to <managed-bean> fragment in "faces-config.xml". This annotation injects a class in the runtime as a managed bean and then can be used accordingly.

Using this annotation, the following "faces-config.xml" fragment from our application:

<managed-bean>         <managed-bean-name>cities</managed-bean-name>         <managed-bean-class>server.Cities</managed-bean-class>         <managed-bean-scope>request</managed-bean-scope>     </managed-bean>     <managed-bean>         <managed-bean-name>dbUtil</managed-bean-name>         <managed-bean-class>server.DatabaseUtil</managed-bean-class>         <managed-bean-scope>request</managed-bean-scope>         <managed-property>             <property-name>cities</property-name>             <value>#{cities}</value>         </managed-property>     </managed-bean>

is simplified to

@Entity @Table(name = "cities") @ManagedBean(name="cities", scope="request") @NamedQueries({@NamedQuery(...)}) public class Cities implements Serializable {

and

@ManagedBean(name="dbUtil", scope="request") public class DatabaseUtil {     @ManagedProperty(value="#{cities}")     private Cities cities;

The specification defines that managed bean declaration in "faces-config.xml" overrides the annotation. Section 11.5.1 of JSF 2.0 EDR2 specification defines several similar annotations that can be used to simplify "faces-config.xml".

Have you tried your JSF 1.2 app on Mojarra 2.0 ? Drop a comment on this blog if you have.

File JSF related bugs here using "2.0.0 EDR1" version and ask your questions on webtier@glassfish.dev.java.net.

Please leave suggestions on other TOTD (Tip Of The Day) that you'd like to see. An archive of all the tips is available here.

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