97 lines
3.9 KiB
HTML
97 lines
3.9 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 Artemis JMS Auto Closable 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 Auto Closable Example</h1>
|
|
|
|
<pre>To run the example, simply type <b>mvn verify</b> from this directory, <br>or <b>mvn -PnoServer verify</b> if you want to start and create the server manually.</pre>
|
|
|
|
<p>This example shows you how JMS resources, such as connections, sessions and consumers, in JMS 2 can be automatically closed on error.</p>
|
|
<p>In this instance we auto close a connection after a subsequent call to a JMS producer send fails</p>
|
|
|
|
<h2>Example step-by-step</h2>
|
|
|
|
<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>
|
|
<pre class="prettyprint">
|
|
<code>InitialContext initialContext = getContext();</code>
|
|
</pre>
|
|
|
|
<li>We look-up the JMS queue object from JNDI</li>
|
|
<pre class="prettyprint">
|
|
<code>Queue queue = (Queue) initialContext.lookup("/queue/exampleQueue");</code>
|
|
</pre>
|
|
|
|
<li>We look-up the JMS connection factory object from JNDI</li>
|
|
<pre class="prettyprint">
|
|
<code>ConnectionFactory cf = (ConnectionFactory) initialContext.lookup("/ConnectionFactory");</code>
|
|
</pre>
|
|
|
|
<li>We create a JMS context but we do it inside the try-with-resources statement like so:</li>
|
|
<pre class="prettyprint">
|
|
<code>
|
|
try
|
|
(
|
|
JMSContext jmsContext = cf.createContext()
|
|
)
|
|
</code>
|
|
</pre>
|
|
|
|
<li>Inside the following try block we first create the producer</li>
|
|
<pre class="prettyprint">
|
|
<code>JMSProducer jmsProducer = jmsContext.createProducer();</code>
|
|
</pre>
|
|
|
|
<li>We then try to send a message. It is this call that throws an exception as the producer doesn't have the privileges
|
|
to send a message</li>
|
|
<pre class="prettyprint">
|
|
<code>jmsProducer.send(queue, "this message will fail security!");</code>
|
|
</pre>
|
|
|
|
<li>We catch the exception from the send message and can do what we want, however the JMSContext will have been closed
|
|
prior to entering the catch block.</li>
|
|
<pre class="prettyprint">
|
|
<code>System.out.println("expected exception from jmsProducer.send: " + e.getMessage());</code>
|
|
</pre>
|
|
|
|
<li>And finally, we close the Initial Context, note we no longer have to worry about clearing up the JMSContext.</li>
|
|
|
|
<pre class="prettyprint">
|
|
<code>finally
|
|
{
|
|
if (initialContext != null)
|
|
{
|
|
initialContext.close();
|
|
}
|
|
}</code>
|
|
</pre>
|
|
|
|
|
|
|
|
</ol>
|
|
</body>
|
|
</html>
|