RMI - Remote Method Invocation

Java Remote Method Invocation (RMI) enables the programmer to create distributed Java technology-based to Java technology-based applications, in which the methods of remote Java objects can be invoked from other Java virtual machines*, possibly on different hosts. A Java technology-based program can make a call on a remote object once it obtains a reference to the remote object, either by looking up the remote object in the bootstrap naming service provided by RMI or by receiving the reference as an argument or a return value. A client can call a remote object in a server, and that server can also be a client of other remote objects. RMI uses object serialization to marshal and unmarshal parameters and does not truncate types, supporting true object-oriented polymorphism.

The Java distributed object model preserves the Java object model in the following ways:

1. reference to a remote object can be passed as an argument or returned as a result in any local or remote method invocation.
2. Developers can use natural Java mechanisms for the type-checking and casting of remote objects.
3. Clients of remote objects interact with remote interfaces.
4. If a remote object reference is passed, the receiver will get a reference to the same remote object.

The Java distributed object model extends the Java object model in several ways:

• Non-remote arguments to - and results from - a remote method invocation are passed by deep copy rather than by value.
• The semantics of some of the methods defined by class Object are specialized for remote objects.