Question

I generated a new form using sean-gen (seam new-form) and added another field to it using an @In annotation:

@Stateful
@Name("dummy")
public class DummyBean implements Dummy
{
    @Logger private Log log;

    @In StatusMessages statusMessages;

    @In private String bar;

    private String foo;

    public void doStuff()
    {
        String msg = "dummy.doStuff() action called with foo: #{dummy.foo} and bar: #{bar}. instance variable for bar:" + bar;
        log.info(msg);
        statusMessages.add(msg);
    }

    @Length(max = 10)
    public String getFoo()
    {
        return foo;
    }

    public void setFoo(String value)
    {
        this.foo = value;
    }

    @Remove
    public void destroy() {}

}

The interface is this one:

@Local
public interface Dummy
{
    public void doStuff();
    public String getFoo();
    public void setFoo(String value);
    public void destroy();
}

The problem is, when I try to access the properties I get:

javax.faces.FacesException: javax.el.ELException: /dummy.xhtml @22,52 value="#{dummy.foo}": Error reading 'foo' on type org.javassist.tmp.java.lang.Object_$$_javassist_seam_2
    at javax.faces.component.UIOutput.getValue(UIOutput.java:187)
    at com.sun.faces.renderkit.html_basic.HtmlBasicInputRenderer.getValue(HtmlBasicInputRenderer.java:201)
    at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.getCurrentValue(HtmlBasicRenderer.java:284)
    at com.sun.faces.renderkit.html_basic.HtmlBasicRenderer.encodeEnd(HtmlBasicRenderer.java:154)
.
.
.
Caused by: javax.ejb.EJBTransactionRolledbackException: @In attribute requires non-null value: dummy.bar
    at org.jboss.ejb3.tx.Ejb3TxPolicy.handleInCallerTx(Ejb3TxPolicy.java:115)
    at org.jboss.aspects.tx.TxPolicy.invokeInCallerTx(TxPolicy.java:130)

My view is this:

<!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"
    xmlns:rich="http://richfaces.org/rich"
    xmlns:a="http://richfaces.org/a4j"
    template="layout/template.xhtml">

<ui:define name="body">

    <h:form id="dummyForm">

        <rich:panel>
            <f:facet name="header">dummy header</f:facet>

             <s:decorate id="fooField" template="layout/edit.xhtml">
                <ui:define name="label">Foo</ui:define>
                <h:inputText id="foo" required="true"
                             value="#{dummy.foo}"/>
            </s:decorate>               

             <s:decorate id="barField" template="layout/edit.xhtml">
                <ui:define name="label">Bar</ui:define>
                <h:inputText id="bar" required="true"
                             value="#{bar}"/>
            </s:decorate>            

            <div style="clear:both"/>

        </rich:panel>

        <div class="actionButtons">
            <h:commandButton id="doStuff" value="doStuff"
                    action="#{dummy.doStuff}"/>
        </div>

    </h:form>

</ui:define>

</ui:composition>

If I remove either ‘fooField‘ or ‘barField‘ the view renders and works correctly, but if I try to use both at the same time I get the above exception.

I also noticed that if I use only @In annotations (remove the accessor methods from the bean) the page works.

Is this something expected and I should be doing my homework before asking?

I’m using JBoss 5.1.0.GA, Seam 2.2.0.GA and Java 6.

Answer 1

Turns out this is expected behavior, quoting an answer from the seam forum:

Use @In(required=false) if the Seam component you’re injecting does not have the @AutoCreate annotation at the class level.

So, changing:

@In private String bar;

to:

@In (required=false) private String bar;

fixes the issue.