lightbulbclient.java

Java网络编程与分布式计算, 主要分析java网络各方面的编程, 提供许多实用安全

import org.omg.CORBA.*;
import org.omg.CosNaming.*;

// Chapter 12, Listing 2
public class LightBulbClient 
{
	public static void main(String args[])
	{
		try
		{
			// First step : initialize our client ORB

			// Create the ORB
			ORB orb = ORB.init(args, null);

			// Second step: lookup the light bulb using nameservice
			// We use the same code from our servant to create the
			// nameservice reference and namecomponent.

			System.out.println ("Looking for lightbulb");

			// Get a name service reference
			org.omg.CORBA.Object object = 
			orb.resolve_initial_references("NameService");

			// Narrow to a NamingContext object
			NamingContext namingContext = 
				NamingContextHelper.narrow(object);

			// Creating a naming component for our light bulb servant
			NameComponent component =
				new NameComponent ("LightBulb", "");

			// NamingContext requires an array, not a single
			// NameComponent
			NameComponent componentList[] = { component };

			// Now, here the client differs. We want to resolve (lookup)
			// the name component representing the light bulb.			
			org.omg.CORBA.Object remoteRef = 
				namingContext.resolve(componentList);

			// Next, we narrow it to get an address book
			LightBulb lb = LightBulbHelper.narrow (remoteRef);
            
			// Finally, we have a remote reference to our light bulb.
			System.out.println ("Found light bulb");

			// Turn bulb on and off till it fails, demonstrating exceptions
			for (;;)
			{
				try
				{
					lb.on();
					System.out.print ("Light on.... ");
					lb.off();
					System.out.print ("Light off.... ");
				}
				catch (BulbBrokenException bbe)
				{
					System.err.println ();
					System.err.println ("Bulb broken exception encountered");
					break;
				}
			}

		}
		catch (Exception e)
		{
			System.err.println ("Error - " + e);
		}

	}

}