In this example we are going to use the ManagedThreadFactory (part of Java EE7 Concurrency Utils) to create and run a background task. The advantage of this, rather than using java.lang.Thread, is that your new thread will have access to the other Java EE services. Using the ManagedThreadFactory ensures your threads are created, and managed, by the container.
Example
Like previous examples, we need a Runnable task which will define what work is to be done in the background.
public class ReportTask implements Runnable {
Logger logger = Logger.getLogger(getClass().getSimpleName());
public void run() {
logger.log(Level.INFO, "New thread running...");
try {
//do your background task
Thread.sleep(10000);
} catch (InterruptedException e) {
logger.log(Level.SEVERE, "Thread interrupted", e);
}
}
}
To get a container managed thread, we simply ask the
ManagedThreadFactory for a new thread, and pass it our Runnable instance. To start the thread we call
start().
@Stateless
public class ReportBean {
@Resource(lookup="java:jboss/ee/concurrency/factory/MyManagedThreadFactory")
private ManagedThreadFactory threadFactory;
public void runReports() {
ReportTask reportTask = new ReportTask();
Thread thread = threadFactory.newThread(reportTask);
thread.start();
}
}
We now need to configure our ManagedThreadFactory within Wildfly. This snippet is taken from the ee subsystem configuration in standalone.xml. The 'lookup' attribute of the @Resource annotation maps to 'jndi-name' attribute within the
<managed-thread-factory> tag.
<subsystem xmlns="urn:jboss:domain:ee:2.0">
...
<managed-thread-factories>
<managed-thread-factory name="default" jndi-name="java:jboss/ee/concurrency/factory/default" context-service="default"/>
<managed-thread-factory name="myManagedThreadFactory" jndi-name="java:jboss/ee/concurrency/factory/MyManagedThreadFactory" context-service="default" priority="1"/>
</managed-thread-factories>
...
</subsystem>
Below is the full list of attributes you can use to configure your
managed-thread-factory in Wildfly.
- name - This is the name of the resource. This attribute is manditory.
- jndi-name - The JNDI name for this resource. This attribute is manditory
- context-service - The context service to use, if not supplied, the default context service is used.
- priority - The priority that the thread should have, from 1 to 10 inclusive. Default is 5.
Using the Command Line Interface (CLI)
To create your ManagedThreadFactory using CLI, go to your terminal and connect to your server by running the following command, swapping out
wildfly for your WildFly root directory:
$ wildfly/bin/jboss-cli.sh --connect
Now create the
ManagedThreadFactory and set its properties by using the
add command, passing through the required property-value pairs.
[standalone@localhost:9990 /] /subsystem=ee/managed-thread-factory=myManagedThreadFactory:add(priority=1,context-service=default,jndi-name=java:jboss/ee/concurrency/factory/MyManagedThreadFactory)
If you want to modify any of these properties use the
write-attribute command, passing though the name of the attribute and the new value:
[standalone@localhost:9990 /] /subsystem=ee/managed-thread-factory=myManagedThreadFactory:write-attribute(name=priority,value=3)
Finally reload the server to make your changes avaliable:
[standalone@localhost:9990 /] /:reload
The Admin Console
To view your thread factory in the Wildfly Admin console, navigate to Runtime > JNDI View > java:jboss > ee > concurrent. Here, you can see all the concurrent resources including your newly configured resource.
Note: Using the JNDI prefix of java:jboss/ee/concurrency/factory ensures that the resource shows under concurrency/factory list in the Wildfly admin console.
