visual basic barcode generator Distributed Objects and Application Servers in Java

Making PDF 417 in Java Distributed Objects and Application Servers

Distributed Objects and Application Servers
Recognizing PDF417 In Java
Using Barcode Control SDK for Java Control to generate, create, read, scan barcode image in Java applications.
Painting PDF417 In Java
Using Barcode creator for Java Control to generate, create PDF417 image in Java applications.
it is both platform and language independent. Furthermore, most application servers (such as IBM s WebSphere, BEA s WebLogic, and JBoss) derive their core functionalities from various components of CORBA. We begin with an overview of CORBA, followed by a more detailed description of the various components of CORBA. In order to demonstrate how the various components fit together, we provide a detailed example of the use of CORBA. Toward the end of the chapter, we discuss application servers, which are closely related to the various components of CORBA. We also provide a brief comparison of Java RMI and CORBA. CORBA Overview The most import component of CORBA is Object Request Broker (ORB). ORB took the idea of marshalling and network communication one big step forward by encapsulating the marshalling code and the networking calls code into a separate software component (application). This separation allowed the same code to be reused by many applications as well as a certain amount of decoupling between the applications by moving away from point-to-point integration. This move away from point-to-point integration may be considered the first step in the evolution of the concept of Enterprise Service Bus (ESB). This is illustrated in Figure 5.1, which shows that multiple applications on the same machine can use the same ORB to communicate with each other as well as with applications on different machines. ORB has additional features that are discussed later in this chapter.
Recognizing PDF417 In Java
Using Barcode recognizer for Java Control to read, scan read, scan image in Java applications.
Barcode Generator In Java
Using Barcode printer for Java Control to generate, create barcode image in Java applications.
Machine 1 Application A Application B Application C
Barcode Decoder In Java
Using Barcode decoder for Java Control to read, scan read, scan image in Java applications.
PDF 417 Encoder In C#.NET
Using Barcode generator for .NET framework Control to generate, create PDF 417 image in .NET applications.
ORB Network ORB
PDF-417 2d Barcode Maker In .NET Framework
Using Barcode creator for ASP.NET Control to generate, create PDF-417 2d barcode image in ASP.NET applications.
Create PDF-417 2d Barcode In .NET
Using Barcode creation for Visual Studio .NET Control to generate, create PDF-417 2d barcode image in Visual Studio .NET applications.
Machine 2
PDF417 Creation In Visual Basic .NET
Using Barcode maker for Visual Studio .NET Control to generate, create PDF417 image in Visual Studio .NET applications.
Barcode Printer In Java
Using Barcode drawer for Java Control to generate, create barcode image in Java applications.
Application D
Printing GS1 DataBar Limited In Java
Using Barcode creation for Java Control to generate, create GS1 DataBar Expanded image in Java applications.
Code-39 Maker In Java
Using Barcode creation for Java Control to generate, create Code 39 image in Java applications.
Application E
MSI Plessey Generation In Java
Using Barcode generator for Java Control to generate, create MSI Plessey image in Java applications.
Data Matrix Reader In Java
Using Barcode scanner for Java Control to read, scan read, scan image in Java applications.
Application F
Creating GS1 - 13 In .NET
Using Barcode creation for ASP.NET Control to generate, create UPC - 13 image in ASP.NET applications.
EAN 13 Maker In None
Using Barcode creation for Software Control to generate, create European Article Number 13 image in Software applications.
ORBs allow applications running on the same machine and on different machines to communicate
UCC - 12 Recognizer In Java
Using Barcode scanner for Java Control to read, scan read, scan image in Java applications.
Barcode Printer In Objective-C
Using Barcode maker for iPhone Control to generate, create bar code image in iPhone applications.
Five
Barcode Scanner In Java
Using Barcode Control SDK for Eclipse BIRT Control to generate, create, read, scan barcode image in Eclipse BIRT applications.
Barcode Scanner In Java
Using Barcode Control SDK for Java Control to generate, create, read, scan barcode image in Java applications.
The second important contribution of CORBA is a method for declaring interfaces in a language-independent manner. Recall that with RPC, the interface is declared in a specific language such as C. CORBA introduced the interface definition language (IDL), which is not a programming language and can only be used to define interfaces. Because interfaces declared in IDL can be mapped to any programming language, the IDL specification is responsible for ensuring that data is properly exchanged between dissimilar languages. Standard mappings for a number of popular programming languages exist, including mappings for C, C++, Java, COBOL, and Smalltalk. IDL is discussed in greater detail later in this chapter. CORBA also defined a standard protocol for the ORBs from various vendors to communicate. This protocol is known as the Internet InterORB Protocol (IIOP). IIOP is built on top of TCP/IP and ensures, in principle, true interoperability among products from different vendors, thus enabling CORBA applications to be more vendor independent. Just like RPC, CORBA includes a client stub. However, the client stub has reduced functionality because the code for marshalling has been taken out of it. It only serves to act as a proxy for the server object and makes the remote calls look like a local call for the client. In addition, CORBA includes a server skeleton, which is a piece of skeleton code that is used to fill in for implementing the server. Of course, the server skeleton is used on the server side. CORBA maintains the notion of client and server. However, the distinction between the client and server is blurred somewhat. Unlike in RPC, in CORBA a component can simultaneously provide and use various services provided by the other objects. These other objects may have remote locations. CORBA also has a distinct object model, which we discuss in detail in the next section. In CORBA, all communications between objects is done through object references. These references are known as interoperable object references (IORs). In other words, remote objects in CORBA remain remote, and objects are not passed by value. Additionally, CORBA provides a number of services, including naming, security, transaction, and persistent object services. We discuss these facilities later in the chapter. CORBA Model In this section, we discuss the major components of the CORBA model in detail. The aspects we discuss are
The Object Request Broker (ORB) The Interface De nition Language (IDL)
Copyright © OnBarcode.com . All rights reserved.