The Common Object Request Broker Architecture (CORBA) is a standard specified by the Object Management Group for distributed object-oriented programming. It is both platform- and language-independent. Implementations of CORBA are available from many vendors for a wide variety of programming languages.
Distributed programming is a paradigm in which software components are installed on physically separated computers and accessed remotely though a network. Examples of distributed programming include Sun's Remote Procedure Calls (RPC), Java's Remote Method Invocation (RMI), Microsoft's Component Object Model (COM), and the Common Object Request Broker Architecture (CORBA). RPC is based on the procedural programming paradigm used by languages such as C and Pascal. With RPC, procedures residing in memory on remote machines are accessed. The other examples listed are based on the object-oriented programming paradigm used by languages such as C++, Java, Smalltalk, and Python. In this case, software objects and their methods are accessed remotely.
Graphical user interfaces are used in modern operating systems that support the concept of “windows”. The windows provide a visual representation of an application and usually have a border and a title to distinguish one window from another. Within the window, there are graphical elements known as “widgets” that make up the full interface. Widgets include pull-down menus, clickable buttons, and scroll bars.
A software tool that reads an IDL file and generates code in a specific language (e.g., Java, C++, Smalltalk, etc.). This code may be anything, but typically, it is stub or skeleton code that is extended by user-defined code that completes the interface implementation.
Several types of “interfaces” exist within the scope of Tweek:
In Java. there is a keyword interface that can be used to define a set of methods that must be part of an implementing class. Classes that claim to implement a given interface must define the methods described by the interface or declare themselves abstract.
In IDL, an interface is essentially identical to a Java interface, but an IDL compiler can generate code from the IDL. The interface methods must still be implemented (by a C++ class, for example), and thus, the main function of an IDL interface is to define a language-independent signature through which CORBA communication may occur.
In C++, there is no interface keyword as in Java and IDL. The term “interface” is typically applied to abstract classes (those with pure virtual methods). More generally, it is use to refer to the collection of methods defined by a class.
The Interface Definition Language is a simple language used to define the interface (or signature) an object will have. An interface is composed solely of methods (functions) that may be invoked on an object (data element). No data members are present in the interface definition. IDL is not tied to a specific language but instead must be compiled into another language where the interface will be implemented.
The Internet Inter-ORB Protocol (IIOP) is part of the CORBA specification. It is used to standardize communication between ORBs so that ORBs from different vendors can inter-operate seamlessly.
JavaBeans are the component architecture of the Java programming language. There are no restrictions on the interfaces implemented by JavaBeans, though it is strongly recommended that they implement java.io.Serializable.
The Java Native Interface is the bridge between a Java virtual machine (JVM) and natively compiled code. Native code can load a JVM and get access to Java objects through it, or Java classes may have native methods that are loaded by the JVM.
An Object Request Broker (ORB) is used by CORBA for management of interface implementation objects (servants) and the references made to those objects. ORBs communicate with each other using a client/server model, though two ORBs may both act as servers and clients during the transactions.
The Portable Object Adapter (POA) the standard object adapter and is part of the CORBA 2.3 specification. It is used together with IIOP to allow ORB implementations from different vendors to communicate. A single ORB may have multiple POAs each tailored to a certain task using parameterized characteristics.
Remote Method Invocation (RMI) is a mechanism for gaining access to remote Java code. It is implemented as part of the Java virtual machine and was originally intended to be comparable to CORBA. RMI allows easy access to code between two virtual machines, but it does not have the cross-language features of CORBA.