visual basic barcode generator Locating the NamingContext Object in Java

Print PDF417 in Java Locating the NamingContext Object

Locating the NamingContext Object
PDF 417 Scanner In Java
Using Barcode Control SDK for Java Control to generate, create, read, scan barcode image in Java applications.
Make PDF 417 In Java
Using Barcode creation for Java Control to generate, create PDF 417 image in Java applications.
Five
Read PDF417 In Java
Using Barcode reader for Java Control to read, scan read, scan image in Java applications.
Barcode Generation In Java
Using Barcode encoder for Java Control to generate, create bar code image in Java applications.
Binding the AccountServer In lines 47 50, we bind the server with the
Bar Code Reader In Java
Using Barcode reader for Java Control to read, scan read, scan image in Java applications.
Paint PDF 417 In Visual C#.NET
Using Barcode creation for .NET Control to generate, create PDF417 image in .NET applications.
naming context using the name AccountServer. After this binding, the clients can query the naming service for an object by this name, which will return a reference to this AccountServerImpl object. object is now registered with the naming service, the only thing left to do is to wait for the clients to invoke methods on this object. The actual handling of these requests for method invocation occurs in a separate thread, so the main() method simply needs to wait indefinitely (see lines 53 55).
Paint PDF417 In .NET Framework
Using Barcode printer for ASP.NET Control to generate, create PDF-417 2d barcode image in ASP.NET applications.
PDF417 Encoder In Visual Studio .NET
Using Barcode creation for Visual Studio .NET Control to generate, create PDF417 image in VS .NET applications.
Waiting for the Clients to Make Requests Because the AccountServerImpl
Paint PDF417 In VB.NET
Using Barcode encoder for .NET Control to generate, create PDF 417 image in .NET framework applications.
Paint GS1 - 12 In Java
Using Barcode creation for Java Control to generate, create UPCA image in Java applications.
Catching Exceptions Lines 56 58 simply catch any exception thrown by the preceding code and print out an error message. All that s left to do on the server side is to compile the Java server code using the Java compiler (javac) and then run the server. Client Implementation
GTIN - 12 Printer In Java
Using Barcode generator for Java Control to generate, create UPC A image in Java applications.
Code 128 Creation In Java
Using Barcode encoder for Java Control to generate, create Code 128 Code Set B image in Java applications.
The client implementation is similar but simpler than the server implementation. It was a conscious design decision to put the complexity on the server side in order to keep the client-side programming as simple as possible. Listing 5-4 shows sample code for a client implementation. This client first obtains a reference to the server and then invokes two methods on the server. The following subsections explain some of the client code.
Code 93 Printer In Java
Using Barcode generator for Java Control to generate, create Code 9/3 image in Java applications.
Bar Code Scanner In Java
Using Barcode recognizer for Java Control to read, scan read, scan image in Java applications.
Listing 5-4
GTIN - 13 Creation In Objective-C
Using Barcode generator for iPad Control to generate, create EAN / UCC - 13 image in iPad applications.
Print Bar Code In C#
Using Barcode drawer for Visual Studio .NET Control to generate, create barcode image in .NET framework applications.
Listing 5.4: SavingAccountClient.java 1 // SavingAccountClient.java 2 3 package SavingAccount; 4 5 import org.omg.CORBA.ORB; 6 import org.omg.CosNaming.NameComponent; 7 import org.omg.CosNaming.NamingContext; 8 import org.omg.CosNaming.NamingContextHelper; 9 10 // simple client of the AccountServer 11 public class SavingAccountClient { 12 // constructor for the client class 13 SavingAccountClient () { 14 } 15 16 public static ORB ourORB; 17 private AccountServer ourAccountServer; 18 19 public static void main (String args []) { 20
Make Data Matrix ECC200 In None
Using Barcode creator for Online Control to generate, create ECC200 image in Online applications.
Make Code 39 In Visual C#.NET
Using Barcode creation for .NET Control to generate, create Code 3/9 image in .NET framework applications.
Distributed Objects and Application Servers
Bar Code Decoder In VB.NET
Using Barcode Control SDK for Visual Studio .NET Control to generate, create, read, scan barcode image in .NET applications.
Scan ANSI/AIM Code 128 In Java
Using Barcode reader for Java Control to read, scan read, scan image in Java applications.
21 // initialize the ORB 22 ourORB = ORB.init (args, null); 23 24 SavingAccountClient client = new SavingAccountClient (); 25 26 try { 27 28 ///Obtain the root naming context 29 org.omg.CORBA.Object obj = ourORB. 30 resolve_initial_references ("NamingService"); 31 NamingContext namingContext = NamingContextHelper. narrow(obj); 32 33 // Try to locate the Accountserver in the naming context 34 NameComponent nameComponent = new NameComponent ( 35 "AccountServer", ""): 36 NameComponent path [] = { nameComponent }; 37 ourAccountServer = AccountServerHelper.narrow (namingContext, 38 resolve ( Path ) ); 39 } 40 catch (Exception ex ) { 41 System.out.println ( "Could not locate the server : " + ex.getMessage () ); 42 return; 43 } 44 // check the initial balance 45 System.out.println ( "The balance before deposit was : " + 46 ourAccountServer.getBalance () ); 47 //deposit $10 and check the balance again 48 System.out.println ( "The balance after the deposit is : $ " + 49 ourAccountServer. deposit (10.0)); 50 } 51 }
Package, Imports, and Class Name
In lines 3 14, we first declare the package name and list the classes that need to be imported. The package name and the import classes are the same as those in the server class. We can choose any class name for the client class. We have chosen the class name SavingAccountClient and defined a no-argument constructor for the class.
Class Members In lines 16 and 17, we declare two class variables. The first is the reference to the ORB we are going to use and the second is a reference to the server on which we are going to invoke two methods.
Five
Main Method and Class Instantiation Every Java program has a main method with standard signature. We declare the main method in the usual way and then initialize our ORB. Next, we instantiate the SavingAccountClient class (see lines 19 24). Obtaining a Reference to the Server In lines 26 43, we obtain a reference to the server by using the naming service. This code is similar to the code on the server side, so it will not be explained further. The code is enclosed in a try/catch block in order to deal with any exceptions that may be thrown in the process of obtaining the reference to the server class. Invoking Methods on the Server
Lines 44 49 are used to invoke two methods on the server. First, we invoke the method getBalance() and print the result. Next we add $10 to the account using the method deposit(). This method returns the new balance, and we print the return value. Note that the method invocation looks like a local method call. This is because the code for marshalling and unmarshalling has been taken out of the client application and incorporated in the ORB. Application Servers We now turn our attention to the commercial products that support distributed objects. These commercial products are commonly known as application servers. Currently, a large number of products are available, including IBM s WebSphere Application Server, IBM s WebSphere Application Server Enterprise Edition, BEA WebLogic Server, JBoss, VisiBroker for Java, VisiBroker for C++, Orbix for Java, and Orbix for C++. The two most common application servers are IBM s WebSphere Application Server and BEA s WebLogic Server. The backbone of all these products consists of some implementation of CORBA s ORB. In addition, these products also support a number of other features of CORBA, including security and transaction services. However, most of these products have been specialized to one particular language or a particular type of application. The most common type of application servers are those that support J2EE applications and the Java development environment. J2EE consists of different types of components, such as Enterprise Java Beans (EJBs), servlets, JSPs, and Java clients. These components, except for the Java client, run in containers that run on top of the underlying ORB. For example, the servlets and JSPs run in a web server, whereas EJBs run in an EJB container. The containers handle system functions for the EJB component and use the underlying ORB to handle the protocols required for client and server interaction. In addition, an EJB can
Copyright © OnBarcode.com . All rights reserved.