/*
* Copyright 2002-2007 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.ejb.support;
import javax.ejb.MessageDrivenBean;
import javax.ejb.MessageDrivenContext;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* Convenient base class for EJB 2.x MDBs.
* Doesn't require JMS, as EJB 2.1 MDBs are no longer JMS-specific;
* see the {@link AbstractJmsMessageDrivenBean} subclass.
*
* <p>This class ensures that subclasses have access to the
* MessageDrivenContext provided by the EJB container, and implement
* a no-arg <code>ejbCreate()</code> method as required by the EJB
* specification. This <code>ejbCreate()</code> method loads a BeanFactory,
* before invoking the <code>onEjbCreate()</code> method, which is
* supposed to contain subclass-specific initialization.
*
* <p>NB: We cannot use final methods to implement EJB API methods,
* as this violates the EJB specification. However, there should be
* no need to override the <code>setMessageDrivenContext</code> or
* <code>ejbCreate()</code> methods.
*
* @author Rod Johnson
*/
public abstract class AbstractMessageDrivenBean extends AbstractEnterpriseBean
implements MessageDrivenBean {
/** Logger available to subclasses */
protected final Log logger = LogFactory.getLog(getClass());
private MessageDrivenContext messageDrivenContext;
/**
* Required lifecycle method. Sets the MessageDriven context.
* @param messageDrivenContext MessageDrivenContext
*/
public void setMessageDrivenContext(MessageDrivenContext messageDrivenContext) {
this.messageDrivenContext = messageDrivenContext;
}
/**
* Convenience method for subclasses to use.
* @return the MessageDrivenContext passed to this EJB by the EJB container
*/
protected final MessageDrivenContext getMessageDrivenContext() {
return this.messageDrivenContext;
}
/**
* Lifecycle method required by the EJB specification but not the
* MessageDrivenBean interface. This implementation loads the BeanFactory.
* <p>Don't override it (although it can't be made final): code initialization
* in onEjbCreate(), which is called when the BeanFactory is available.
* <p>Unfortunately we can't load the BeanFactory in setSessionContext(),
* as resource manager access isn't permitted and the BeanFactory may require it.
*/
public void ejbCreate() {
loadBeanFactory();
onEjbCreate();
}
/**
* Subclasses must implement this method to do any initialization they would
* otherwise have done in an <code>ejbCreate()</code> method. In contrast
* to <code>ejbCreate()</code>, the BeanFactory will have been loaded here.
* <p>The same restrictions apply to the work of this method as
* to an <code>ejbCreate()</code> method.
*/
protected abstract void onEjbCreate();
}
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