This is the second tutorial about Camel 3. In the first one (Getting started with Camel 3) we have discussed how to set up a basic Camel 3 projects and run a simple demo with it. Now we will show how to use the messasing API to connect to a remote ArtemisMQ embedded in a WildFly distribution.
Assumed that you have already set up a basic Camel project, let’s create the Route class which does the work to send JMS messages to the Queue named “demoQueue”:
package com.mastertheboss.camel;
import org.apache.camel.builder.RouteBuilder;
public class MyJMSRouteBuilder extends RouteBuilder {
@Override
public void configure() throws Exception {
from("timer:foo?period=3s")
.transform(constant("Hello World"))
.to("jms:queue:demoQueue");
from("jms:queue:demoQueue").to("log:demoQueue");
}
}
The RouteBuilder class will send JMS messages containing “Hello World” every 3 seconds.
Now the Camel Main class to start the route:
package com.mastertheboss.camel;
import org.apache.camel.main.Main;
/**
* A Camel Application
*/
public class MainApp {
/**
* A main() so we can easily run these routing rules in our IDE
*/
public static void main(String... args) throws Exception {
// use Camels Main class
Main main = new Main();
// and add the routes (you can specify multiple classes)
main.addRouteBuilder(MyJMSRouteBuilder.class);
// now keep the application running until the JVM is terminated (ctrl + c or sigterm)
main.run(args);
}
}
That’s all. Within our application.properties we will setup JMS component with connection to ActiveMQ Artemis broker:
camel.main.name = CamelJMSHelloWorld # properties used in the route myCron = 0/2 * * * * ? # setup JMS component with connection to ActiveMQ Artemis broker camel.component.jms.connection-factory.brokerURL=tcp://localhost:61616 camel.component.jms.connection-factory.target-connection-factory.user=guest camel.component.jms.connection-factory.target-connection-factory.password=guest
Now let’s move to the WildFly side. Start by creating a JMS remote acceptor which is bound to port 61616:
/socket-binding-group=standard-sockets/socket-binding=artemis-server:add(port=61616) /subsystem=messaging-activemq/server=default/remote-acceptor=artemis-acceptor:add(socket-binding=artemis-server)
Within the messaging susbsytem you should be able to see:
<subsystem xmlns="urn:jboss:domain:messaging-activemq:8.0">
<server name="default">
<!-- default configuration here -->
<remote-acceptor name="artemis-acceptor" socket-binding="artemis-server"/>
</server>
</subsystem>
In turn, the remote-acceptor references a socket-binding bound to port 61616:
<socket-binding-group name="standard-sockets" default-interface="public" port-offset="${jboss.socket.binding.port-offset:0}">
<socket-binding name="artemis-server" port="61616"/>
<!-- Other bindings -->
</socket-binding-group>
Next, let’s create as well the JMS Queue named demoQueue from the CLI:
jms-queue add --queue-address=demoQueue --entries=queues/demoQueue
Finally, we need to create an user which is allowed to connect to the JMS server. Within our Camel configuration we have already configured it to be guest/guest therefore we will add this user with the shell script add-user.sh:
$ ./add-user.sh
What type of user do you wish to add?
a) Management User (mgmt-users.properties)
b) Application User (application-users.properties)
(a): b
Enter the details of the new user to add.
Using realm 'ApplicationRealm' as discovered from the existing property files.
Username : guest
Password recommendations are listed below. To modify these restrictions edit the add-user.properties configuration file.
- The password should be different from the username
- The password should not be one of the following restricted values {root, admin, administrator}
- The password should contain at least 8 characters, 1 alphabetic character(s), 1 digit(s), 1 non-alphanumeric symbol(s)
Password :
WFLYDM0098: The password should be different from the username
Are you sure you want to use the password entered yes/no? yes
Re-enter Password :
What groups do you want this user to belong to? (Please enter a comma separated list, or leave blank for none)[ ]: guest
About to add user 'guest' for realm 'ApplicationRealm'
Is this correct yes/no? yes
Added user 'guest' to file '/home/francesco/jboss/wildfly-18.0.1.Final/standalone/configuration/application-users.properties'
Added user 'guest' to file '/home/francesco/jboss/wildfly-18.0.1.Final/domain/configuration/application-users.properties'
Added user 'guest' with groups guest to file '/home/francesco/jboss/wildfly-18.0.1.Final/standalone/configuration/application-roles.properties'
Added user 'guest' with groups guest to file '/home/francesco/jboss/wildfly-18.0.1.Final/domain/configuration/application-roles.properties'
Is this new user going to be used for one AS process to connect to another AS process?
e.g. for a slave host controller connecting to the master or for a Remoting connection for server to server EJB calls.
yes/no? yes
We are done! On before launching the Camel Main, we need to generate autowiring for the dependencies found in our project, so we will run:
mvn camel-main:generate
Now we can finally run the Camel main with:
mvn exec:java
You should be able to see, from the CLI or Web console that messages are being received in the Queue demoQueue:
/subsystem=messaging-activemq/server=default/jms-queue=demoQueue:read-resource(include-runtime=true)
{
"outcome" => "success",
"result" => {
"consumer-count" => 1,
"dead-letter-address" => "jms.queue.DLQ",
"delivering-count" => 0,
"durable" => true,
"entries" => ["queues/demoQueue"],
"expiry-address" => "jms.queue.ExpiryQueue",
"legacy-entries" => undefined,
"message-count" => 0L,
"messages-added" => 24L,
"paused" => false,
"queue-address" => "jms.queue.demoQueue",
"scheduled-count" => 0L,
"selector" => undefined,
"temporary" => false
}
}
