138 lines
6.1 KiB
HTML
138 lines
6.1 KiB
HTML
<!--
|
|
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.
|
|
-->
|
|
|
|
<html>
|
|
<head>
|
|
<title>ActiveMQ JMS Instantiate Connection Factory Example</title>
|
|
<link rel="stylesheet" type="text/css" href="../common/common.css" />
|
|
<link rel="stylesheet" type="text/css" href="../common/prettify.css" />
|
|
<script type="text/javascript" src="../common/prettify.js"></script>
|
|
</head>
|
|
<body onload="prettyPrint()">
|
|
<h1>JMS Instantiate Connection Factory Example</h1>
|
|
|
|
<p>Usually, JMS Objects such as ConnectionFactories, Queue and Topic instances are looked up from JNDI
|
|
before being used by the client code. This objects are called "administered objects" in JMS specification
|
|
terminology.</p>
|
|
<p>However, in some cases a JNDI server may not be available or desired. To come to the rescue ActiveMQ
|
|
also supports the direct instantiation of these administered objects on the client side.</p>
|
|
<p>This allows the full set of JMS functionality to be available without requiring a JNDI server!</p>
|
|
<p>This example is very simple and based on the simple Queue example, however in this example we
|
|
instantiate the JMS Queue and ConnectionFactory objects directly.</p>
|
|
<p>A wide variety of methods are available for instantiating ConnectionFactory objects. In this example
|
|
we use a simple method which just takes the server connection details so it knows where to make the
|
|
connection to.</p>
|
|
<p>Other methods are available so all the connection factory parameters can be specified
|
|
including specifying UDP discovery so the client does not need hard-wired knowledge of where the servers
|
|
are that it wishes to connect to, or for specifying live-backup pairs of servers for failover.</p>
|
|
<p>For more information on instantiating ConnectionFactories directly please consult the user manual and
|
|
javadoc.</p>
|
|
|
|
<h2>Example step-by-step</h2>
|
|
<p><i>To run the example, simply type <code>mvn verify -Pexample</code> from this directory</i></p>
|
|
|
|
<ol>
|
|
<li>Instead of looking it up from JNDI we directly instantiate the JMS Queue object. We
|
|
pass in the name of the JMS Queue in the constructor. The actual JMS Queue must already be deployed on
|
|
the server.</li>
|
|
<pre class="prettyprint">
|
|
<code>
|
|
Queue queue = new ActiveMQQueue("exampleQueue");</code>
|
|
</pre>
|
|
|
|
<li>Instantiate the TransportConfiguration object. The TransportConfiguration instance encapsulates
|
|
the connection details of the server we're connecting to. In this case we're using Netty as a transport, and
|
|
we're specifying to connect on port 61617.</li>
|
|
<pre class="prettyprint">
|
|
<code>
|
|
Map<String, Object> connectionParams = new HashMap<String, Object>();
|
|
|
|
connectionParams.put(PORT_PROP_NAME, 61617);
|
|
|
|
TransportConfiguration transportConfiguration = new TransportConfiguration(NettyConnectorFactory.class.getName(),
|
|
connectionParams);
|
|
|
|
</code>
|
|
</pre>
|
|
|
|
<li>Directly instantiate the JMS ConnectionFactory object using that TransportConfiguration.</li>
|
|
<pre class="prettyprint">
|
|
<code>
|
|
ConnectionFactory cf = ActiveMQJMSClient.createConnectionFactoryWithoutHA(transportConfiguration);
|
|
</code>
|
|
</pre>
|
|
|
|
<li>We create a JMS connection</li>
|
|
<pre class="prettyprint">
|
|
<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>
|
|
<pre class="prettyprint">
|
|
<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>
|
|
<pre class="prettyprint">
|
|
<code>MessageProducer messageProducer = session.createProducer(topic);</code>
|
|
</pre>
|
|
|
|
<li>We create a JMS text message that we are going to send.</li>
|
|
<pre class="prettyprint">
|
|
<code>TextMessage message = session.createTextMessage("This is a text message");</code>
|
|
</pre>
|
|
|
|
<li>We send message to the queue</li>
|
|
<pre class="prettyprint">
|
|
<code>messageProducer.send(message);</code>
|
|
</pre>
|
|
|
|
<li>We create a JMS Message Consumer to receive the message.</li>
|
|
<pre class="prettyprint">
|
|
<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>
|
|
<pre class="prettyprint">
|
|
<code>connection.start();</code>
|
|
</pre>
|
|
|
|
<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>
|
|
<pre class="prettyprint">
|
|
<code>TextMessage messageReceived = (TextMessage) messageConsumer.receive(5000);</code>
|
|
</pre>
|
|
|
|
<li>And finally, <b>always</b> remember to close your resources after use, in a <code>finally</code> block.</li>
|
|
|
|
<pre class="prettyprint">
|
|
<code>finally
|
|
{
|
|
if (connection != null)
|
|
{
|
|
connection.close();
|
|
}
|
|
}</code>
|
|
</pre>
|
|
|
|
|
|
|
|
</ol>
|
|
</body>
|
|
</html>
|