Java Enterprise in a Nutshell, Third Edition

Chapter 14. Java IDL (CORBA)

The Java IDL API provides an interface between Java programs and distributed objects built using the Common Object Request Broker Architecture (CORBA). CORBA is a standard defined by the Object Management Group (OMG). It describes architecture, interfaces, and protocols that distributed objects can use to interact with each other. Part of the CORBA standard is the Interface Definition Language (IDL), which is an implementation-independent language for describing the interfaces of remote-capable objects. Standard mappings are defined by the OMG for converting IDL interfaces into C++ classes, C code, and Java classes, among others (a complete list is provided later in the chapter). These generated classes use the underlying CORBA framework to communicate with remote clients and give you the basis for implementing and exporting your own distributed objects. Java IDL is Sun’s implementation of the standard IDL-to-Java mapping and is provided by Sun’s JDK in the org.omg.CORBA package, the org.omg.CosNaming package, and other org.omg.* packages.

Like RMI, Java IDL gives you a way to access remote objects over the network. It also provides the tools you need to make your objects accessible to other CORBA clients. If you export a Java class using Java IDL, it’s possible to create an instance of that class and publish it through a naming/directory service. A remote client can find this object, call methods on it, and receive data from it, just as if it were running ...