Before we use the client to deploy and call our service, lets take a closer look at what happened during its construction:

public Client(final boolean useBus) throws Exception {

    this.useBus = useBus;



    ClassLoader cl = Thread.currentThread().getContextClassLoader();

    url = cl.getResource("jboss-beans.xml");



    // Start JBoss Microcontainer

    bootstrap = new EmbeddedBootstrap();

    bootstrap.run();



    kernel = bootstrap.getKernel();

    controller = kernel.getController();

    bus = kernel.getBus();

 }

First of all a url representing the jboss-beans.xml deployment descriptor was created. This is required later on by the XML deployer so that we can deploy and undeploy beans declared in the file. Here we have chosen to use the getResource() method of the application classloader as we deliberately placed the jboss-beans.xml file on the classpath. However, this is not a requirement and you are free to call the deployment descriptor anything you like and place it anywhere you want provided that the URL is valid and reachable.

Next we created an instance of JBoss Microcontainer together with an XML deployer. This process is called bootstrapping and for convenience a BasicBootstrap class is provided as part of the microcontainer to allow for configuration via system properties. To add an XML deployer we simply extend BasicBootstrap to create an EmbeddedBootstrap class and override the protected bootstrap() method as follows:

public class EmbeddedBootstrap extends BasicBootstrap {



    protected BasicXMLDeployer deployer;



    public EmbeddedBootstrap() throws Exception {

        super();

    }



    public void bootstrap() throws Throwable {

        super.bootstrap();

        deployer = new BasicXMLDeployer(getKernel());

        Runtime.getRuntime().addShutdownHook(new Shutdown());

    }



    public void deploy(URL url) {

        ...

        deployer.deploy(url);

        ...

    }



    public void undeploy(URL url) {

        ...

        deployer.undeploy(url);

        ...

    }



    protected class Shutdown extends Thread {

        public void run() {

            log.info("Shutting down");

            deployer.shutdown();

        }

    }

}

The shutdown hook ensures that when the JVM is exited all of the beans are undeployed in the correct order. The public deploy/undeploy methods simply delegate to the BasicXMLDeployer so that we can deploy and undeploy beans declared in our jboss-beans.xml file.

Finally we stored references to the microcontainer controller and bus so that we can lookup bean references by name and access them directly or indirectly as necessary.