Whats the correct way to create multiple instances of managed beans in JSF 2.0

Question

If I want to create more than one instance of managed bean in JSF 2.0, under different names in the same scope, how should I proceed? Ideally, I want the equivilant to (for example):

@ManagedBeans({name="myManagedBean1",name="myManagedBean2"})
@RequestScoped
public class MyManagedBean {

}

Thanks ..

Answer 1

You can't. It technically also doesn't make much sense. You're probably looking for a solution in the wrong direction for the particular functional requirement.

Your best bet is to have a parent bean and have those "multiple beans" as children.

@ManagedBean
@RequestScoped
public class Parent {
    private Child child1;
    private Child child2;
    // ...
}

so that you can access it by #{parent.child1} and #{parent.child2}. You can of course also use a List<Child> property or even Map<String, Child> instead to be more flexible.

With the faces-config.xml it's however possible to define multiple bean classes with a different name. Still then, I don't see how that's useful.

Answer 2

In your case you should make use of the faces-config.xml. Implment your bean without the ManagedBean and RequestScope annotation. So your bean will not become a managed bean per default. You can than instance as much managedBeans as you need with different names, different scopes and at lease differnent properties. For example:

    <managed-bean>
    <managed-bean-name>MyManagedBean1</managed-bean-name>
    <managed-bean-class>org.MyManagedBean</managed-bean-class>
    <managed-bean-scope>session</managed-bean-scope>
    <managed-property>
        <property-name>value1</property-name>
        <property-class>int</property-class>
        <value>5</value>
    </managed-property>
    <managed-property>
        <property-name>value2</property-name>
        <property-class>int</property-class>
        <value>2</value>
    </managed-property>
</managed-bean>

<managed-bean>
    <managed-bean-name>MyManagedBean2</managed-bean-name>
    <managed-bean-class>org.MyManagedBean</managed-bean-class>
    <managed-bean-scope>view</managed-bean-scope>
    <managed-property>
        <property-name>value1</property-name>
        <property-class>int</property-class>
        <value>30</value>
    </managed-property>
    <managed-property>
        <property-name>value2</property-name>
        <property-class>java.lang.String</property-class>
        <value>project</value>
    </managed-property>
</managed-bean>

Don't think that descriptors are evil and annotations are the only way to implement your code.