What is the difference between Java RMI and RPC?

Question

What is the actual difference between Java RMI and RPC?

I have read in some places that RMI uses Objects?

Answer 1

RMI or Remote Method Invokation is very similar to RPC or Remote Procedure call in that the client both send proxy objects (or stubs) to the server however the subtle difference is that client side RPC invokes FUNCTIONS through the proxy function and RMI invokes METHODS through the proxy function. RMI is considered slightly superior as it is an object-oriented version of RPC.

From here.

For more information and examples, have a look here.

Answer 2

RPC is C based, and as such it has structured programming semantics, on the other side, RMI is a Java only technology and it's object oriented.

With RPC you just call remote functions exported in a server, in RMI you can have references to remote objects and invoke their methods, and also pass and return more remote object references that can be distributed among many JVM instances, so it's much more powerful.

RMI stands out when the need to develop something more complex than a pure client-server architecture arises. It's very easy to spread out objects over a network enabling all the clients to communicate without having to stablish individual connections explicitly.

Answer 3

The main difference between RPC and RMI is that RMI involves objects. Instead of calling procedures remotely by use of a proxy function, we instead use a proxy object.

There is greater transparency with RMI, namely due the exploitation of objects, references, inheritance, polymorphism, and exceptions as the technology is integrated into the language.

RMI is also more advanced than RPC, allowing for dynamic invocation, where interfaces can to change at runtime, and object adaption, providing an additional layer of abstraction.

Answer 4

The only real difference between RPC and RMI is that there is objects involved in RMI: instead of invoking functions through a proxy function, we invoke methods through a proxy.