jca/src/main/java/org/apache/qpid/ra/admin/QpidDestinationProxy.java

/*
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.qpid.ra.admin;

import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.io.Serializable;

import javax.jms.Destination;
import javax.naming.NamingException;
import javax.naming.Reference;
import javax.naming.Referenceable;
import javax.naming.spi.ObjectFactory;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * The QpidDestinationProxy provides for allowing an administrator/developer to
 * create and bind QPID destinations into a JNDI tree. AdminObjects are used as
 * an generic integration point rather than relying on the EE server specific
 * API's to create destinations (queues, topics). AdminObjects and associated
 * properties are defined in the ra.xml file for a particular JCA adapter.
 * Please see the ra.xml file for the QPID JCA resource adapter as well as the
 * README.txt for the adapter for more details.
 *
 */
public class QpidDestinationProxy implements Externalizable, Referenceable, Destination, Serializable
{
    private static final long serialVersionUID = -1137413782643796461L;

    private static final Logger _log = LoggerFactory.getLogger(QpidDestinationProxy.class);

    private static final String DEFAULT_QUEUE_TYPE = "QUEUE";

    private static final String DEFAULT_TOPIC_TYPE = "TOPIC";

    private String _destinationAddress;

    private String _destinationType;

    private Destination _delegate;

    /**
     * This constructor should not only be used be de-serialisation code. Create
     * original object with the other constructor.
     */
    public QpidDestinationProxy()
    {
    }

    public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException
    {
        Reference ref = (Reference) in.readObject();

        try
        {
            _delegate = (Destination) dereference(ref);

        } catch (Exception e)
        {
            _log.error("Failed to dereference Destination " + e.getMessage(), e);
            throw new IOException("Failed to dereference Destination: " + e.getMessage());
        }
    }

    public void writeExternal(ObjectOutput out) throws IOException
    {
        if (_delegate == null)
        {
            _log.error("Null Destination ");
            throw new IOException("Null destination!");
        }

        try
        {
            out.writeObject(((Referenceable) _delegate).getReference());
        }
        catch (NamingException e)
        {
            _log.error("Failed to dereference Destination " + e.getMessage(), e);
            throw new IOException("Failed to dereference Destination: " + e.getMessage());
        }
    }

    @Override
    public Reference getReference() throws NamingException
    {
        try
        {
            if(getDestinationType().equalsIgnoreCase(DEFAULT_QUEUE_TYPE))
            {
                _delegate = new QpidQueueImpl(getDestinationAddress());
            }
            else if(getDestinationType().equalsIgnoreCase(DEFAULT_TOPIC_TYPE))
            {
                _delegate = new QpidTopicImpl(getDestinationAddress());
            }
            else
            {
                throw new IllegalStateException("Unknown destination type " + getDestinationType());
            }

            return ((Referenceable) _delegate).getReference();

        }
        catch(Exception e)
        {
            _log.error(e.getMessage(),e);
            throw new NamingException("Failed to create destination " + e.getMessage());
        }

    }

    private Object dereference(Reference ref) throws Exception
    {
        ObjectFactory objFactory = (ObjectFactory) Class.forName(
                ref.getFactoryClassName()).newInstance();
        return objFactory.getObjectInstance(ref, null, null, null);
    }

    public void setDestinationAddress(String destinationAddress) throws Exception
    {
        this._destinationAddress = destinationAddress;
    }

    public String getDestinationAddress()
    {
        return this._destinationAddress;
    }

    public void setDestinationType(String destinationType)
    {
        this._destinationType = destinationType;
    }

    public String getDestinationType()
    {
        return this._destinationType;
    }
}