I have a JSF page containing a datatable showing a list of customers retrieved from the database. The datatable is linked with a backing bean which retrieves the customers from database using a hibernate session.

The last column of each row in the table has a button. When pressed it will call a method on the backing bean to retrieve the details of that customer.

I made this entirely based on the "hibernate" example supplied with seam.

I got it working so that the customers are retrieved by the backing bean from the injected hibernate session. The problem is that when I press the button, an ajax call is made to the backing bean, but here it goes wrong. I get an exception:

Caused by: org.jboss.seam.RequiredException: @In attribute requires non-null value: userTableDataModel.bookingDatabase
 at org.jboss.seam.Component.getValueToInject(Component.java:2168)
 at org.jboss.seam.Component.injectAttributes(Component.java:1598)
 at org.jboss.seam.Component.inject(Component.java:1416)
 at org.jboss.seam.core.BijectionInterceptor.aroundInvoke(BijectionInterceptor.java:45)
 at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
 at org.jboss.seam.core.MethodContextInterceptor.aroundInvoke(MethodContextInterceptor.java:42)
 at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
 at org.jboss.seam.core.SynchronizationInterceptor.aroundInvoke(SynchronizationInterceptor.java:32)
 at org.jboss.seam.intercept.SeamInvocationContext.proceed(SeamInvocationContext.java:68)
 at org.jboss.seam.intercept.RootInterceptor.invoke(RootInterceptor.java:107)
 at org.jboss.seam.intercept.JavaBeanInterceptor.interceptInvocation(JavaBeanInterceptor.java:166)
 at org.jboss.seam.intercept.JavaBeanInterceptor.invoke(JavaBeanInterceptor.java:102)
 at be.application.UserTableBean_$$_javassist_1.setDataTable(UserTableBean_$$_javassist_1.java)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
 at java.lang.reflect.Method.invoke(Unknown Source)
 at javax.el.BeanELResolver.setValue(BeanELResolver.java:108)
 ... 52 more

Fact is that it wasnt' null when the datatable was loaded the first time. Apparantly it gets "null" when a second method on the backing bean is invoked.

I tried about everything, but I cannot figure out why I'm getting this.
Any help would be greatly appreciated.

I'm using:

Seam 2.0.1
JBoss 4.2
Trinidad, Richfaces, Tomahawk

My code:

Name("userTableDataModel")
@Scope(ScopeType.SESSION)
public class UserTableBean implements Serializable {

 @In
 Session bookingDatabase;
 public List getListAll() {
 customerList = bookingDatabase.createQuery("select c from CustomerTO as c").list();
 return customerList;
 }

public void showDetails()
{
System.out.println("Showing detail");
}
}

As you see the show detail is not doing anything besides printing something in the log -- untill now it doesn't get invoked since I'm getting the error prior the method could be invoked.

My faces config:

<faces-config>
 <managed-bean>
 <managed-bean-name>userTableDataModel</managed-bean-name>
 <managed-bean-class>
 be.application.UserTableBean
 </managed-bean-class>
 <managed-bean-scope>session</managed-bean-scope>
 </managed-bean>
</faces-config>

The relevant parts of web.xml

 <filter>
 <filter-name>Seam Filter</filter-name>
 <filter-class>org.jboss.seam.servlet.SeamFilter</filter-class>
 </filter>

 <filter>
 <filter-name>Seam Exception Filter</filter-name>
 <filter-class>
 org.jboss.seam.servlet.SeamExceptionFilter
 </filter-class>
 </filter>

 <filter-mapping>
 <filter-name>Seam Filter</filter-name>
 <url-pattern>/*</url-pattern>
 </filter-mapping>

 <filter-mapping>
 <filter-name>Seam Exception Filter</filter-name>
 <url-pattern>*.jsf</url-pattern>
 </filter-mapping>

 <listener>
 <listener-class>org.jboss.seam.servlet.SeamListener</listener-class>
 </listener>

 <servlet>
 <servlet-name>Faces Servlet</servlet-name>
 <servlet-class>javax.faces.webapp.FacesServlet</servlet-class>
 <load-on-startup>1</load-on-startup>
 </servlet>

 <servlet-mapping>
 <servlet-name>Faces Servlet</servlet-name>
 <url-pattern>*.jsf</url-pattern>
 </servlet-mapping>

 <servlet-mapping>
 <servlet-name>Faces Servlet</servlet-name>
 <url-pattern>/faces/*</url-pattern>
 </servlet-mapping>

Components.xml

 <core:manager conversation-timeout="120000"
 concurrent-request-timeout="500" conversation-id-parameter="cid" />

 <persistence:hibernate-session-factory
 name="hibernateSessionFactory" />

 <persistence:managed-hibernate-session name="bookingDatabase"
 session-factory="#{hibernateSessionFactory}" auto-create="true" />

 <transaction:hibernate-transaction session="#{bookingDatabase}" />

Hibernate config:

<hibernate-configuration>
 <session-factory name="java:/bookingDatabase">
 <property name="show_sql">true</property>
 <property name="connection.datasource">java:jdbc/db</property>
 <property name="cache.provider_class">org.hibernate.cache.HashtableCacheProvider</property>
 <property name="transaction.flush_before_completion">true</property>
 <property name="transaction.manager_lookup_class">org.hibernate.transaction.JBossTransactionManagerLookup</property>
 <property name="transaction.factory_class">org.hibernate.transaction.JTATransactionFactory</property>
 <mapping resource="be/backend/Customer.hbm.xml"/>
 <mapping resource="be/backend/Product.hbm.xml"/>
 </session-factory>
</hibernate-configuration>

The command button to get the details:

 <a4j:commandButton id="show_detail"
 action="#{userTableDataModel.showDetail}"
 value="#{msg['userinformation.showdetail']}"