helloclient.java

精通EJB3.0一书的全部随书实例的源代码。

package examples;

import javax.naming.Context;
import javax.naming.InitialContext;
import java.util.Properties;

/**
 * This class is an example of client code which invokes
 * methods on a simple stateless session bean.
 */
public class HelloClient {

	public static void main(String[] args) throws Exception {
		/*
		 * Setup properties for JNDI initialization.
		 *
		 * These properties will be read-in from
		 * the command-line.
		 */
		Properties props = System.getProperties();

		/*
		 * Obtain the JNDI initial context.
		 *
		 * The initial context is a starting point for
		 * connecting to a JNDI tree. We choose our JNDI
		 * driver, the network location of the server, etc
		 * by passing in the environment properties.
		 */
		Context ctx = new InitialContext(props);

		/*
		 * Get a reference to the home object - the
		 * factory for Hello EJB Objects
		 */
		Object obj = ctx.lookup("HelloHome");


		/*
		 * Home objects are RMI-IIOP objects, and so
		 * they must be cast into RMI-IIOP objects
		 * using a special RMI-IIOP cast.
		 *
		 * See Appendix X for more details on this.
		 */
		HelloHome home = (HelloHome)
			javax.rmi.PortableRemoteObject.narrow(
				obj, HelloHome.class);

		/*
		 * Use the factory to create the Hello EJB Object
		 */
		Hello hello = home.create();

		/*
		 * Call the hello() method on the EJB object.  The
		 * EJB object will delegate the call to the bean,
		 * receive the result, and return it to us.
		 *
		 * We then print the result to the screen.
		 */
		System.out.println(hello.hello());

		/*
		 * Done with EJB Object, so remove it.
		 * The container will destroy the EJB object.
		 */
		hello.remove();
	}
}