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ACTIVEMQ6-1 - Initial HornetQ Donation Commit https://issues.apache.org/jira/browse/ACTIVEMQ6-1 This is the initial donation of the HornetQ codebase as per document http://incubator.apache.org/ip-clearance/hornetq.html
2014-10-31 06:20:28 -04:00
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Remove references to HornetQ in doc and Comments
2014-11-19 03:44:57 -05:00
<title>ActiveMQ EJB/JMS Transaction Example</title>
ACTIVEMQ6-1 - Initial HornetQ Donation Commit https://issues.apache.org/jira/browse/ACTIVEMQ6-1 This is the initial donation of the HornetQ codebase as per document http://incubator.apache.org/ip-clearance/hornetq.html
2014-10-31 06:20:28 -04:00
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<h1>EJB/JMS Transaction Example</h1>
<p>The example application will invoke an EJB which is deployed within WildFly which will:</p>
<ol>
<li>start an XA transaction</li>
<li>send a JMS message</li>
<li>update an in-memory database</li>
<li>commit the transaction</li>
</ol>
<p>The example application will then receive the message sent by the EJB.</p>
<h2>WildFly configuration</h2>
<p>The example leverages the Arquillian framework to run a WildFly instance and deploy the MDB.</p>
<h2>Example step-by-step</h2>
<p><i>download WildFly 8.0.0.Final from <a href="http://wildfly.org/downloads/">here</a> and install.</i></p>
<p><i>set the JBOSS_HOME property to point to the WildFly install directory</i></p>
<p><i>type <code>mvn verify</code> from the example directory to run</i></p>
<p>The example code is composed of two main classes:</p>
<ul>
<li><code>EJBClientExample</code></li> - the example application
<li><code>SendMessageBean</code></li> - a Stateless EJB with a remote interface
</ul>
<h3>Example Application</h3>
<p>Let's take a look at EJBClientExample first.</p>
<ol>
<li>First we need to get an initial context so we can look-up the EJB. This initial context will get it's properties from the jboss-ejb-client.properties.</li>
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Properties env = new Properties();
env.put(Context.URL_PKG_PREFIXES, "org.jboss.ejb.client.naming");
InitialContext initialContext = new InitialContext();
</pre>
<li>We look up the EJB</li>
<pre class="prettyprint">
ACTIVEMQ6-3 renaming package names from activemq6 to activemq 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.
2014-11-17 09:23:06 -05:00
SendMessageService service = (SendMessageService) initialContext.lookup("ejb:/test//SendMessageBean!org.apache.activemq.javaee.example.server.SendMessageService");
ACTIVEMQ6-1 - Initial HornetQ Donation Commit https://issues.apache.org/jira/browse/ACTIVEMQ6-1 This is the initial donation of the HornetQ codebase as per document http://incubator.apache.org/ip-clearance/hornetq.html
2014-10-31 06:20:28 -04:00
</pre>
<li>We create the DB table which will be updated if it does not already exist</li>
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service.createTable();
</pre>
<li>We invoke the EJB's <code>sendAndUpdate</code> method. This method will send a JMS text message (with the text passed in parameter)
and insert a row in the database table with the text and the message's JMS Message ID</li>
<pre class="prettyprint">
service.sendAndUpdate("This is a text message");
</pre>
<p><em>We will now consume the JMS message which was sent by the EJB at step 4.</em></p>
<li>We need to get a new initial context so we can look-up the JMS connection factory and destination objects from JNDI.</li>
<pre class="prettyprint">
env = new Properties();
env.put(Context.INITIAL_CONTEXT_FACTORY, "org.jboss.naming.remote.client.InitialContextFactory");
env.put(Context.PROVIDER_URL, "http-remoting://localhost:8080");
initialContext = new InitialContext(env);
</pre>
<li>We look up the JMS connection factory</li>
<pre class="prettyprint">
ConnectionFactory cf = (ConnectionFactory)initialContext.lookup("jms/RemoteConnectionFactory");
</pre>
<li>We lookup the JMS queue</li>
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Queue queue = (Queue)initialContext.lookup("jms/queues/testQueue");
</pre>
<li>We create a connection, a session and a message consumer for the queue</li>
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connection = cf.createConnection("guest", "password");
Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
MessageConsumer consumer = session.createConsumer(queue);
</pre>
<li>We start the JMS connection</li>
<pre class="prettyprint">
connection.start();
</pre>
<li>We receive a message from the queue. It corresponds to the message sent by the EJB</li>
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TextMessage messageReceived = (TextMessage)consumer.receive(5000);
System.out.println("Received message: " + messageReceived.getText() + " (" + messageReceived.getJMSMessageID() + ")");
</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>
<pre class="prettyprint">
finally
{
if (initialContext != null)
{
initialContext.close();
}
if (connection != null)
{
connection.close();
}
}
</pre>
</ol>
<h3>EJB Example</h3>
<p>Let's now take a look at the EJB example</p>
<ol>
<li>First, we create a new initial context</li>
<pre class="prettyprint">
ic = new InitialContext();
</pre>
<li>We look up the JMS <em>XA</em> Connection Factory (which is bound to <code>java:/JmsXA</code>)</li>
<pre class="prettyprint">
ConnectionFactory cf = (ConnectionFactory)ic.lookup("java:/JmsXA");
</pre>
<li>We look up the JMS Queue</li>
<pre class="prettyprint">
Queue queue = (Queue)ic.lookup("queue/testQueue");
</pre>
<li>We create a JMS connection, a session and a message producer for the queue</li>
<pre class="prettyprint">
jmsConnection = cf.createConnection();
Session session = jmsConnection.createSession(false, Session.AUTO_ACKNOWLEDGE);
MessageProducer messageProducer = session.createProducer(queue);
</pre>
<li>We create a text message with the text passed in parameter of the EJB method</li>
<pre class="prettyprint">
TextMessage message = session.createTextMessage(text);
</pre>
<li>We send the message to the queue</li>
<pre class="prettyprint">
messageProducer.send(message);
System.out.println("Sent message: " + message.getText() + "(" + message.getJMSMessageID() + ")");
</pre>
<li>We now lookup the JDBC <em>XA</em> DataSource</li>
<pre class="prettyprint">
DataSource ds = (DataSource)ic.lookup("java:/XADS");
</pre>
<li>We retrieve a JDBC connection</li>
<pre class="prettyprint">
jdbcConnection = ds.getConnection();
</pre>
<li>We create a prepared statement to insert the text and message's ID in the DB table</li>
<pre class="prettyprint">
PreparedStatement pr = jdbcConnection.prepareStatement("INSERT INTO " + TABLE
+ " (id, text) VALUES ('" + message.getJMSMessageID() + "', '" + text + "');");
</pre>
<li>We execute the prepared statement</li>
<pre class="prettyprint">
pr.execute();
</pre>
<li>We close the prepared statement</li>
<pre class="prettyprint">
pr.close();
</pre>
<li>And finally, <b>always</b> remember to close all your connections and resources (for both JMS and JDBC) after use, in a <code>finally</code> block.</li>
<pre class="prettyprint">
finally
{
if (ic != null)
{
ic.close();
}
if (jmsConnection != null)
{
jmsConnection.close();
}
if (jdbcConnection != null)
{
jdbcConnection.close();
}
}
</pre>
</ol>
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