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This topic includes the following sections:
Remote Method Invocation (RMI) is a Java based programming paradigm and application programming interface (API) for distributed object computing and Web connectivity. RMI allows an application to obtain a reference to an object that exists elsewhere on the network but then invoke methods on that object as though it existed locally on the client's Java virtual machine. So, products, services, and resources can exist anywhere on the network but appear to the programmer and the end user to be part of the local environment.
With RMI, a client object can call a remote object in a server, and that server can also be a client of other remote objects.RMI uses some form of Java serialization to marshal (encode) and unmarshal (de-code) parameters sent across a network. Serialization is a way of encoding parameters into a byte stream for delivery across a network.
The BEA WebLogic Enterprise (WLE) development platform provides remote method invocation (RMI) as one of the standard services of a Java 2 Enterprise Edition (J2EE) implementation. For this release, WLE provides its own protocol of WebLogic RMI on the Object Management Group's industry-standard Internet Inter-Orb Protocol (IIOP). IIOP is a protocol that enables browsers and servers to exchange integers, arrays, and more complex objects, unlike HTTP which supports only transmission of text.
The primary advantage of the WLE implementation of RMI on IIOP is that it allows application developers to write remote interfaces between WLE clients and EJB servers, using a natural Java API. By making a few code enhancements, developers can also convert their legacy Java client/RMI server applications to work in WLE. WLE RMI clients can talk to EJBs and traditional RMI server objects.
WLE RMI has the following characteristics and capabilities:
What is RMI?
What is WebLogic RMI on IIOP?
For this release, WLE IIOP does not pass Objects by Value which is needed for full CORBA interoperability support. Instead, WLE RMI on IIOP passes serialized objects as in traditional RMI. Therefore, this release of WLE does not support complete interoperability between Java clients, EJBs, and CORBA objects.
All clients of Enterprise Java Beans (EJB) use RMI on IIOP. Creating a client to an EJB server is essentially the same as creating an RMI client to a traditional RMI server. For more information on this, see the topic Using RMI with EJBs. For examples of clients of EJBs using RMI on IIOP to talk to EJB servers, see the WebLogic Enterprise 5.0 EJB Sample Applications For more information about remote method invocation, refer to the The Sun Microsystems, Inc. Java site at http://java.sun.com/.
Before you can start developing WLE RMI applications, you need the following:
What about RMI clients of EJBs?
Where can I learn more about RMI?
What software and development environment do I need for WLE RMI?
For information on installing WebLogic Enterprise, see the product installation guide.
For more information on setting up your development environment, see the topic Setting Up Your WLE Development Environment.
For information on the JDK, refer to the The Sun Microsystems, Inc. Java site at http://java.sun.com/.
The following topics are covered in this guide for WebLogic Enterprise RMI on IIOP:
What is next?
For more information about using transactions in your RMI applications, see Using Transactions in the WebLogic Enterprise online documentation.
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