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javajakarta-eejmsrmidistributed-system

What is the difference between Java RMI and JMS?

When designing an distributed application in Java there seem to be a few technologies that address the same kind of problem. I have briefly read about Java Remote Method Invocation and Java Message Service, but it is hard to really see the difference. Java RMI seems to be more tightly coupled than JMS because JMS uses asynchronous communication, but otherwise I don't see any big differences.

  • What is the difference between them?
  • Is one of them newer than the other one?
  • Which one is more common/popular in enterprises?
  • What advantages do they have over each other?
  • When is one preferred over the other?
  • Do they differ much in how difficult they are to implement?

I also think that Web Services and CORBA address the same problem.

Solution

  • You cannot really compare the two, its apples and oranges.

    RMI is a form of Remote Procedure Call (RPC). It is a lightweight, Java specific API that expects the caller and receiver to be available at the time of communication.

    JMS is a reliable messaging API. JMS providers exist for various messaging systems. Messages can be passed even if one of the parties is not available if the provider implements that. The two I am familiar with are TIBCO and IBM MQ.

    RMI doesn't deal with guaranteed delivery or asynchronous responses, JMS may, depending on the provider.

    JMS allows loose coupling in the sense of availability. "Web Services" allows loose coupling in the sense of protocol and data but doesn't specify much in the way of reliable messaging, though some implementations do include this (Windows Communication Foundation) and some don't.

    EDITED: Revised per comments. When I wrote this answer in 2010 my experience was actually with only one JMS provider and I didn't actually know there was no default JMS provider.