SeamLoginModule EntityManager injection difficulties

[trickyvail]

I am running Seam version 1.1.6 on a JBoss 4.0.5.GA server.

While following the example from the Seam documentation (page 124) for creating a SeamLoginModule authentication method I have run into the following error:

09:37:41,228 ERROR [SeamLoginModule] Error invoking login method
javax.faces.el.EvaluationException: Exception while invoking expression #{authenticator.authenticate}
 at org.apache.myfaces.el.MethodBindingImpl.invoke(MethodBindingImpl.java:153)
 at org.jboss.seam.actionparam.ActionParamBindingHelper.invokeTheExpression(ActionParamBindingHelper.java:59)
 at org.jboss.seam.actionparam.ActionParamMethodBinding.invoke(ActionParamMethodBinding.java:74)
[SNIP]
 at java.lang.Thread.run(Thread.java:595)
Caused by: org.jboss.seam.RequiredException: In attribute requires value for component: authenticator.entityManager
 at org.jboss.seam.Component.getInstanceToInject(Component.java:1920)
 at org.jboss.seam.Component.injectFields(Component.java:1386)
 at org.jboss.seam.Component.inject(Component.java:1156)
[SNIP]
 ... 59 more

This suggests that Seam is unable to locate and inject the entityManager by its component name. The relevant java bean that the login component is calling is as follows:

@Name("authenticator")
public class Authenticator
{
 @In EntityManager entityManager;

 public boolean authenticate()
 {
 return true;
 }
}

For completeness here, is the form that is calling the validation:

<!DOCTYPE composition PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
 "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<ui:composition xmlns="http://www.w3.org/1999/xhtml"
 xmlns:s="http://jboss.com/products/seam/taglib"
 xmlns:ui="http://java.sun.com/jsf/facelets"
 xmlns:f="http://java.sun.com/jsf/core"
 xmlns:h="http://java.sun.com/jsf/html"
 template="layout/template.xhtml">

<ui:define name="body">

 <h1>Login</h1>
 <p>Please login using any username and password</p>

 <h:messages styleClass="message"/>

 <h:form>

 <div class="dialog">
 <div class="prop">
 <span class="name">Username</span>
 <span class="value">
 <h:inputText id="username" value="#{identity.username}"/>
 </span>
 </div>
 <div class="prop">
 <span class="name">Password</span>
 <span class="value">
 <h:inputSecret id="password" value="#{identity.password}"/>
 </span>
 </div>
 <div class="prop">
 <span class="name">Remember me</span>
 <span class="value">
 <h:selectBooleanCheckbox id="rememberMe" value="#{identity.rememberMe}"/>
 </span>
 </div>
 </div>

 <div class="actionButtons">
 <h:commandButton value="Login" action="#{identity.login}"/>
 </div>

 </h:form>

</ui:define>
</ui:composition>

I have also tried to annotate the EntityManager object in the following ways:

@In("entityManager") EntityManager entityManager;

@In(value="entityManager") EntityManager entityManager;

but have recieved the same error.

My configuration was generated by seam-gen and the authenticate method works fine until I try to inject an EntityManager into the component.

I will create a Stateful Session Bean in order to try to inject the EntityManager by the EJB3.0 annotation @PersistenceContext rather than Seam @In annotation.

Could this be caused by a filter loading order? I've looked at web.xml and it does not seem to be the cause. I think too that the identity component is a Seam component (ie. eats its own dogfood), therefore should not be a problem, Maybe the identity component is instantiated before other components like the entity manager?

P.S. Thank you Gavin King for all your past helpful answers.

[fernando_jmt]

Ttry with this:

 @In(create=true)
 private EntityManager entityManager;

Or

Do you have configured the persistence context in your components.xml, like this:

<core:managed-persistence-context name="entityManager" auto-create="true" persistence-unit-jndi-name="java:/...EntityManagerFactory"/>

[gavin.king]

create=true is not required if you set auto-create=true :-)

[trickyvail]

That worked like a charm.

This leaves me wondering how some of my other java bean componenets manage to have Seam inject the EntityManager (without create=true). I will assume some other component is instantiating it and outjecting it prior to those injection calls.

Thank you both very much.

[gavin.king]

Its much better to use auto-create=true for persistence contexts.

[trickyvail]

Thank you Gavin. I have made the change you recomended and it works perfectly.

For anyone else that is follwing this thread please note that I edited the components.xml file to include the following:

<core:managed-persistence-context
 name="entityManager"
 auto-create="true"
 persistence-unit-jndi-name="java:/NewSeamEntityManagerFactory"
 />