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https://issues.apache.org/jira/browse/ACTIVEMQ6-3 We are renaming packages from activemq6 to activemq as that's more generic and version independent The previous commit renamed the directories. On this commit now I'm changing the code. If we changed the code and the directories on the same commit git would remove and add a lot of files without recognizing the renames.
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<h1>JMS Interceptor Example</h1>
<p>This example shows you how to implement and configure a simple incoming, server-side interceptor with HornetQ.</p>
<p>HornetQ allows an application to use an interceptor to hook into the messaging system. All that needs to do is to implement the
Interceptor interface, as defined below: </p>
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<code>
public interface Interceptor
{
boolean intercept(Packet packet, RemotingConnection connection) throws HornetQException;
}
</code>
</pre>
<p>Once you have your own interceptor class, add it to the hornetq-configuration.xml, as follows:</p>
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<code>
<configuration>
...
<remoting-incoming-interceptors>
<class-name>org.apache.activemq.jms.example.SimpleInterceptor</class-name>
</remoting-incoming-interceptors>
...
</configuration>
</code>
</pre>
<p>With interceptor, you can handle various events in message processing. In this example, a simple interceptor, SimpleInterceptor, is implemented and configured.
When the example is running, the interceptor will print out each events that are passed in the interceptor. And it will add a string property to the message being
delivered. You can see that after the message is received, there will be a new string property appears in the received message.</p>
<p>With our interceptor we always return <code>true</code> from the <code>intercept</code> method. If we were
to return <code>false</code> that signifies that no more interceptors are to run or the target
is not to be called. Return <code>false</code> to abort processing of the packet.</p>
<h2>Example step-by-step</h2>
<p><i>To run the example, simply type <code>mvn verify</code> from this directory</i></p>
<ol>
<li>First we need to get an initial context so we can look-up the JMS connection factory and destination objects from JNDI. This initial context will get it's properties from the <code>client-jndi.properties</code> file in the directory <code>../common/config</code></li>
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<code>InitialContext initialContext = getContext(0);</code>
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<li>We look-up the JMS queue object from JNDI</li>
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<code>Queue queue = (Queue) initialContext.lookup("/queue/exampleQueue");</code>
</pre>
<li>We look-up the JMS connection factory object from JNDI</li>
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<code>ConnectionFactory cf = (ConnectionFactory) initialContext.lookup("/ConnectionFactory");</code>
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<li>We create a JMS connection</li>
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<code>connection = cf.createConnection();</code>
</pre>
<li>We create a JMS session. The session is created as non transacted and will auto acknowledge messages.</li>
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<code>Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);</code>
</pre>
<li>We create a JMS message producer on the session. This will be used to send the messages.</li>
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<code>MessageProducer messageProducer = session.createProducer(topic);</code>
</pre>
<li>We create a JMS text message that we are going to send.</li>
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<code>TextMessage message = session.createTextMessage("This is a text message");</code>
</pre>
<li>We send message to the queue</li>
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<code>messageProducer.send(message);</code>
</pre>
<li>We create a JMS Message Consumer to receive the message.</li>
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<code>MessageConsumer messageConsumer = session.createConsumer(queue);</code>
</pre>
<li>We start the connection. In order for delivery to occur on any consumers or subscribers on a connection, the connection must be started</li>
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<code>connection.start();</code>
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<li>The message arrives at the consumer. In this case we use a timeout of 5000 milliseconds but we could use a blocking 'receive()'</li>
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<code>TextMessage messageReceived = (TextMessage) messageConsumer.receive(5000);</code>
</pre>
<li>We print out the message and the new property that has been added by the interceptor</li>
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<code>System.out.println("Received message [" + messageReceived.getText() + "] with String property: " + messageReceived.getStringProperty("newproperty"));</code>
</pre>
<li>And finally, <b>always</b> remember to close your JMS connections and resources after use, in a <code>finally</code> block. Closing a JMS connection will automatically close all of its sessions, consumers, producer and browser objects</li>
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<code>
finally
{
if (initialContext != null)
{
initialContext.close();
}
if (connection != null)
{
connection.close();
}
}
</code>
</pre>
</ol>
<ol>
<li>The SimpleInterceptor:</li>
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<code>
public class SimpleInterceptor implements Interceptor
{
public boolean intercept(Packet packet, RemotingConnection connection) throws HornetQException
{
System.out.println("SimpleInterceptor gets called!");
System.out.println("Packet: " + packet.getClass().getName());
System.out.println("RemotingConnection: " + connection.getRemoteAddress());
if (packet instanceof SessionSendMessage)
{
SessionSendMessage realPacket = (SessionSendMessage)packet;
Message msg = realPacket.getServerMessage();
msg.putStringProperty(new SimpleString("newproperty"), new SimpleString("Hello from interceptor!"));
}
return true;
}
}
</code>
</pre>
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