8.5. Invoking Session Beans

Procedure 8.8. Add Maven Project Configuration for Remote Invocation of Session Beans

1. Add the required project dependencies
   The pom.xml for the project must be updated to include the necessary dependencies.
2. Add the jboss-ejb-client.properties file
   The JBoss EJB client API expects to find a file in the root of the project named jboss-ejb-client.properties that contains the connection information for the JNDI service. Add this file to the src/main/resources/ directory of your project with the following content.

   # In the following line, set SSL_ENABLED to true for SSL
   remote.connectionprovider.create.options.org.xnio.Options.SSL_ENABLED=false
   remote.connections=default
   # Uncomment the following line to set SSL_STARTTLS to true for SSL
   # remote.connection.default.connect.options.org.xnio.Options.SSL_STARTTLS=true
   remote.connection.default.host=localhost
   remote.connection.default.port = 4447
   remote.connection.default.connect.options.org.xnio.Options.SASL_POLICY_NOANONYMOUS=false
   # Add any of the following SASL options if required
   # remote.connection.default.connect.options.org.xnio.Options.SASL_POLICY_NOANONYMOUS=false
   # remote.connection.default.connect.options.org.xnio.Options.SASL_POLICY_NOPLAINTEXT=false
   # remote.connection.default.connect.options.org.xnio.Options.SASL_DISALLOWED_MECHANISMS=JBOSS-LOCAL-USER
   

   Change the host name and port to match your server. 4447 is the default port number. For a secure connection, set the SSL_ENABLED line to true and uncomment the SSL_STARTTLS line. The Remoting interface in the container supports secured and unsecured connections using the same port.
3. Add dependencies for the remote business interfaces
   Add the Maven dependencies to the pom.xml for the remote business interfaces of the session beans.

   <dependency>
      <groupId>org.jboss.as.quickstarts</groupId>
      <artifactId>jboss-ejb-remote-server-side</artifactId>
      <type>ejb-client</type>
      <version>${project.version}</version>
   </dependency>

Procedure 8.9. Obtain a Bean Proxy using JNDI and Invoke Methods of the Bean

1. Handle checked exceptions
   Two of the methods used in the following code (InitialContext() and lookup()) have a checked exception of type javax.naming.NamingException. These method calls must either be enclosed in a try/catch block that catches NamingException or in a method that is declared to throw NamingException. The ejb-remote quickstart uses the second technique.
2. Create a JNDI Context
   A JNDI Context object provides the mechanism for requesting resources from the server. Create a JNDI context using the following code:

   final Hashtable jndiProperties = new Hashtable();
   jndiProperties.put(Context.URL_PKG_PREFIXES, "org.jboss.ejb.client.naming");
   final Context context = new InitialContext(jndiProperties);

   The connection properties for the JNDI service are read from the jboss-ejb-client.properties file.
3. Use the JNDI Context's lookup() method to obtain a bean proxy
   Invoke the lookup() method of the bean proxy and pass it the JNDI name of the session bean you require. This will return an object that must be cast to the type of the remote business interface that contains the methods you want to invoke.

   
   final RemoteCalculator statelessRemoteCalculator = (RemoteCalculator) context.lookup(
       "ejb:/jboss-ejb-remote-server-side//CalculatorBean!" + 
       RemoteCalculator.class.getName());
   

   Session bean JNDI names are defined using a special syntax. For more information, see Section 8.8.1, “EJB JNDI Naming Reference” .
4. Invoke methods
   Now that you have a proxy bean object you can invoke any of the methods contained in the remote business interface.

   int a = 204;
   int b = 340;
   System.out.println("Adding " + a + " and " + b + " via the remote stateless calculator deployed on the server");
   int sum = statelessRemoteCalculator.add(a, b);
   System.out.println("Remote calculator returned sum = " + sum);

   The proxy bean passes the method invocation request to the session bean on the server, where it is executed. The result is returned to the proxy bean which then returns it to the caller. The communication between the proxy bean and the remote session bean is transparent to the caller.

Procedure 8.10. Configure an EJB Using a Map-Based Scoped Context

1. Set the Properties

   Configure the EJB client properties programmatically, specifying the same set of properties that are used in the standard jboss-ejb-client.properties file. To enable the scoped context, you must specify the org.jboss.ejb.client.scoped.context property and set its value to true. The following is an example that configures the properties programmatically.

   // Configure  EJB Client properties for the InitialContext
   Properties ejbClientContextProps = new Properties();
   ejbClientContextProps.put(“remote.connections”,”name1”);
   ejbClientContextProps.put(“remote.connection.name1.host”,”localhost”);
   ejbClientContextProps.put(“remote.connection.name1.port”,”4447”);
   // Property to enable scoped EJB client context which will be tied to the JNDI context
   ejbClientContextProps.put("org.jboss.ejb.client.scoped.context", “true”);
   

2. Pass the Properties on the Context Creation

   // Create the context using the configured properties
   InitialContext ic = new InitialContext(ejbClientContextProps);
   MySLSB bean = ic.lookup("ejb:myapp/ejb//MySLSBBean!" + MySLSB.class.getName());