Why I don't like Java RMI and how I use it anyways

Submitted by Michael Starzinger on Tue, 2010-04-06 21:05

The Java Remote Method Invocation API is a great thing to have because it is available in almost every J2SE runtime environment without adding further dependencies. However there are some implications when using RMI and I just cannot get my head around them:

  1. Interfaces used as remote interfaces need to extend java.rmi.Remote. Interfaces should be clean and not contain any clutter introduced by a certain technology. This is even more true with modern frameworks and things like dependency injection.
  2. Remote methods need to declare java.rmi.RemoteException in their throws clause. This is basically a continuation of the first point. This point holds, even if you ignore the rant about checked exceptions, which I don’t want to comment on right now.
  3. Remote objects need to be exported explicitly. Even though one explicitly declared which methods should be accessible from a remote site with the above two points, one still needs to explicitly export every single instance of an object implementing those methods.

Don’t get me wrong, all those implications have their right to exist because the decisions leading up to them were made for a reason. But in some circumstances those reasons don’t apply. It is just not the one-to-rule-them-all solution for remote method invocation in Java.

There are ways around those problems. One could for instance duplicate the existing interfaces to fit the needs of RMI. But frankly speaking, I just don’t want to do that myself.

That being said, lets see if the task of separating the transportation layer based on RMI from your precious interfaces can be automated in some way, so it doesn’t have to be done by hand. The following are the key points of the approach:

  • Interfaces can explicitly be marked as remote interfaces at runtime without the need for recompiling them. All methods exposed by such an interface can be invoked from a remote site. All parameters which are subclasses of such interfaces, will be passed by-reference and will not be serialized. This is just the same behavior as if the interface would extend java.rmi.Remote in the RMI world. The actual remote interfaces are generated on-demand at runtime.
  • Provide a proxy factory which supports the rapid development of a transportation layer based on RMI for given clean interfaces. The interface classes do not need to be cluttered with specifics of the transportation implementation.
  • A proxy in this context is a transparent object implementing both, the local and the generated remote interface. Both interfaces are usable:
    • Cast the proxy to java.rmi.Remote and use it with any naming or registry service available to the RMI world. Every proxy implicitly is a remote object without the need for explicitly exporting it.
    • Cast the proxy to your local interface and don’t bother whether it actually targets a local or a remote site.
  • The decision how an invocation actually is dispatched can be solely based on whether the target object of a proxy is a remote or a local one. This decision is hidden inside the transportation layer.

Available as a download attached to this post you’ll find a first reference implementation of such a proxy factory as described above. Note that it is just a sketch to illustrate my point and will probably contain major flaws. Also it brings a dependency on Javassist, which kind of contradicts the very first sentence of this post. However it is capable of distributing this tiny example across several sites without modifying the given interfaces, which also represents my only test-case:

public interface Client {
	public void callback(String message);
}
 
public interface Server {
	public void subscribe(Client subscriber);
	public void notify(String message);
}
 
public class ClientImpl implements Client {
	public void callback(String message) {
		// ... do some important job ...
	}
}
 
public class ServerImpl implements Server {
	public void subscribe(Client subscriber) {
		// ... remember "subscriber" in some fancy data structure ...
	}
	public void notify(String message) {
		// ... invoke all "subscribers" like they were local ...
	}
}

This is my attempt to show how I personally think that RMI should have been designed in the first place. Please feel free to comment, improve, ignore or flame.

Attachments: 
text/x-java iconProxyFactory.java

If you are interested in your

Submitted by Anonymous (not verified) on Wed, 2023-08-09 09:57.

If you are interested in your favorite actors' heights and detailed information, please take a look at https://www.celebheightwiki.com/ database.

I completely understand the

Submitted by lanai screens fort myers (not verified) on Sun, 2023-08-13 04:43.

I completely understand the frustration with the intricacies of Java RMI. It's great that it's readily available in the J2SE runtime environment, but the requirements for interfaces, RemoteException, and explicit exporting can be cumbersome. Your approach of automating the generation of remote interfaces and providing a proxy factory to handle the transportation layer sounds like a clever way to address these issues. It simplifies the development process while keeping the local and remote aspects transparent. It's always exciting to see innovative solutions to improve existing technologies.

This is some complicated code

Submitted by Concrete Contractors Lincoln NE (not verified) on Sat, 2023-04-15 20:44.

This is some complicated code that I never would have been able to figure out myself. Thanks for this.

Same here. I even need Chat

Submitted by coralspringstreeservices (not verified) on Fri, 2023-09-08 08:07.

Same here. I even need Chat GPT to explain to me what this is.

Thanks for sharing! Check out

Submitted by Marysville WA Painters (not verified) on Fri, 2022-12-16 04:32.

Thanks for sharing! Check out Marysville WA's best painters

Agree! Mrs. Hanes -

Submitted by mrshanes (not verified) on Thu, 2023-01-26 12:55.

Agree!

Mrs. Hanes - https://www.colourinyourlife.com.au/members/bathroommakeover/profile/

Fantastic! Thank you, I've

Submitted by Almira Holton (not verified) on Fri, 2022-12-02 09:29.

Fantastic! Thank you, I've recently been looking for information about this topic https://www.drywallcoquitlambc.com/

The article is well-written

Submitted by flooring installation Surrey (not verified) on Fri, 2023-05-26 03:42.

The article is well-written and clear in its criticism of RMIRex, and it provides valuable insights for anyone considering using this technology. I believe that this article would be useful for anyone interested in the topic of RMI over HTTP and its drawbacks. Overall, I think the article is a well-written and informative critique of a technology that is often overlooked in the realm of Distributed Computing. I appreciate the author's clear and concise critique of the technology and I think it's a valuable article for anyone interested in the topic.

Wow, this is so great! Thanks

Submitted by Social Security Card (not verified) on Thu, 2022-11-17 18:33.

Wow, this is so great! Thanks

The net worth of a person

Submitted by celeb networth (not verified) on Wed, 2022-10-12 08:51.

The net worth of a person expresses how rich and popular they are, let's see who is the #1 at the present in https://www.celebnetworthpost.com

Fantastic! I think You put a

Submitted by Roof Repair (not verified) on Tue, 2022-10-11 12:36.

Fantastic! I think You put a lot of effort to create this article. I appreciate your work.

Wow that was unusual. I just

Submitted by itex-science.net (not verified) on Sat, 2023-09-09 18:36.

Wow that was unusual. I just wrote an really long comment but after I clicked submit my comment didn't appear.
Grrrr... well I'm not writing all that over again.
Regardless, just wanted to say wonderful blog!

The blog post offers a valid

Submitted by smart kitchen storage (not verified) on Fri, 2023-05-12 00:08.

The blog post offers a valid perspective on the challenges and limitations of RMI, and provides useful insights for developers who are evaluating different options for distributed systems. However, it's worth noting that RMI has been used successfully in many applications and remains a viable option for some use cases. As with any technology, it's important to carefully evaluate the pros and cons before making a decision on whether or not to use it.

RMI is a software component

Submitted by https://playpc.io/reviews/live-a-live-review/ (not verified) on Wed, 2022-08-24 15:17.

RMI is a software component and a Java technology. It does link together various components of programs (and processes). Java is geared around objects. Therefore, it is unquestionably possible to integrate all of these definitions and claim that RMI is an object-oriented middleware.

I wonder how a lot attempts

Submitted by www.tejadosavila.com (not verified) on Wed, 2022-08-31 02:52.

I wonder how a lot attempts you set to make this kind of excellent informative site.

try and try until you

Submitted by Oil Tank Removal (not verified) on Fri, 2022-10-14 07:27.

try and try until you succeed. this should not stop you from achieving your goals.

When an object is sent from

Submitted by when will pokemon sword and shield be playable (not verified) on Wed, 2022-08-24 15:16.

When an object is sent from one Java virtual machine to another Java virtual machine, RMI considers it differently from a non-remote object. RMI sends a remote stub for a remote object rather than copying the implementation object into the receiving Java virtual machine.

I don't like RMI too.

Submitted by armynavyoutdoors.com (not verified) on Tue, 2022-08-30 15:04.

I don't like RMI too.

Thanks for sharing this great

Submitted by veneers plainview (not verified) on Thu, 2022-06-09 17:58.

Thanks for sharing this great article here.

Thanks for sharing the

Submitted by Excavation Leads (not verified) on Wed, 2022-08-17 14:13.

Thanks for sharing the article. I had a great time reading this, the article was informative and useful.

There are several reasons why

Submitted by Mesa (not verified) on Fri, 2022-07-01 06:55.

There are several reasons why I don't like Java RMI. First, it is very difficult to use. The documentation is terrible, and the code is often needlessly complex. Second, it is very slow. Third, it is not very reliable. Fourth, it does not scale well. Finally, it is not very secure. Anyway, if you'd like the best air duct cleaning in Mesa, contact https://www.airanddryerventcleaningmesa.com to provide exceptional service.

Thanks for sharing your

Submitted by Pool companies Santa Clarita (not verified) on Wed, 2022-06-08 12:50.

Thanks for sharing your experience. Keep on posting.

The idea of automating the

Submitted by portstluciescreens.com (not verified) on Fri, 2023-09-15 08:10.

The idea of automating the separation of the transportation layer from interfaces is proposed, potentially simplifying RMI development. The example provided demonstrates this concept. While it acknowledges some limitations, it encourages discussion on improving RMI in Java. Overall, it offers a promising direction for development in this area.

Thanks for sharing here an

Submitted by gilbert pest control (not verified) on Fri, 2022-06-03 13:29.

Thanks for sharing here an informative article.

It's great to see this great

Submitted by rock climbing gym gilbert arizona (not verified) on Wed, 2022-04-27 15:17.

It's great to see this great article here.

I appreciate how the author

Submitted by Augusta Drywall Contractors (not verified) on Thu, 2022-06-02 04:04.

I appreciate how the author explores and presents his thoughts on Java RMI. I'm also grateful that the author explained how he utilizes it.

I like how the author

Submitted by Shane (not verified) on Sun, 2022-05-15 03:58.

I like how the author discusses and expresses his opinion on Java RMI. Also, thankful here that the author shared how he uses it. Anyway, if you need the best home insulation service in Phoenix, I recommend you check this: https://www.insulationinstallphoenix.com/

This may possibly be quite

Submitted by tree service Coventry (not verified) on Mon, 2022-11-14 16:47.

This may possibly be quite helpful for some within your work opportunities I plan to never only with my web site

This is one of the first

Submitted by Heat Pumps (not verified) on Wed, 2022-04-20 20:19.

This is one of the first times where I've had someone say exactly what I'm feeling. Thank you!

It's truly very complex in

Submitted by Virtual Reality Company (not verified) on Thu, 2023-03-16 01:37.

It's truly very complex in this busy life to listen news on TV,
therefore I simply use the web for that purpose, and take the hottest news.

I understand the feeling.

Submitted by Gerald (not verified) on Wed, 2022-05-18 15:44.

I understand the feeling. That's what I felt too. By the way, if you want the best tile and grout cleaning service in Glendale, try https://www.tileandgroutcleaningprosglendale.com/ today.

Thanks for the very useful

Submitted by Visit website (not verified) on Tue, 2022-05-24 04:25.

Thanks for the very useful facts!

Thankful To You For Sharing

Submitted by https://www.solarpanelscentralcoast.com/ (not verified) on Wed, 2022-04-13 12:34.

Thankful To You For Sharing Amazing And Unique Content On Your Web Blog. Please also check our website at

Thanks for this, keep on

Submitted by laptop repair sunnyside ny (not verified) on Tue, 2022-04-12 18:23.

Thanks for this, keep on posting.

I'm amazed at the content of

Submitted by solar panel cleaning fresno (not verified) on Fri, 2022-04-08 15:55.

I'm amazed at the content of your article, very informative.

Interesting article you

Submitted by accountant hurricane (not verified) on Fri, 2022-04-08 11:56.

Interesting article you posted here.

I agree with your statement.

Submitted by tileandgroutcleaningprosgilbert.com (not verified) on Tue, 2022-05-24 02:46.

I agree with your statement. In fact, I learned something new today.

Thanks for sharing nice

Submitted by Epoxy Flooring Yonkers, NY (not verified) on Mon, 2022-04-04 08:54.

Thanks for sharing nice content.

Rasomojo stalo kedes dirbant

Submitted by Rasomojo stalo kedes (not verified) on Fri, 2022-03-25 06:13.

Rasomojo stalo kedes dirbant labia padeda susikaupti. Noredami patogiai dirbti ar zaisti su kompiuteriu, naudokite rasomojo stalo kedes.

Thanks for sharing good

Submitted by Dustless Floor Refinishing (not verified) on Mon, 2022-03-21 12:36.

Thanks for sharing good ideas. Keep on sharing!

Such an interesting post.

Submitted by For more info (not verified) on Fri, 2022-03-11 03:48.

Such an interesting post. I've learned quite a few from reading this. Thanks!

Looking forward to more great

Submitted by bathtub reglazing sandy utah (not verified) on Thu, 2022-03-10 17:35.

Looking forward to more great post from here.

Thanks for sharing your

Submitted by brake repair saskatoon (not verified) on Tue, 2022-03-08 15:03.

Thanks for sharing your insights about JAVA, useful info.

Thank you very much for

Submitted by commercial cleaning nanaimo (not verified) on Fri, 2022-03-04 15:16.

Thank you very much for sharing this one.

Great! You explained it very

Submitted by Cincinnati SEO agency (not verified) on Thu, 2022-02-24 12:00.

Great! You explained it very well, Thanks for the detailed information.

Yes yes, I think what you're

Submitted by esvrm.com (not verified) on Fri, 2022-02-18 18:46.

Yes yes, I think what you're doing is still absolutely brilliant! Keep up the good job.

Thanks for posting this one.

Submitted by fencing clearwater (not verified) on Thu, 2022-02-17 15:30.

Thanks for posting this one. So informative.

Good reasons you have for not

Submitted by Click here (not verified) on Thu, 2021-10-21 20:40.

Good reasons you have for not liking Java RMI and wise one for finding a way to use it anyway.Very wise indeed,Thanks for sharing.

I think what you wrote made a

Submitted by https://vivida-apps.com/ (not verified) on Wed, 2023-09-13 22:59.

I think what you wrote made a bunch of sense. But,
what about this? suppose you were to write a killer headline?
I am not suggesting your information isn't solid, however suppose you
added a post title to possibly grab people's attention?
I mean Reply to comment | antforge.org is a little boring.

You should look at Yahoo's front page and note how they write article titles to get viewers to open the links.
You might try adding a video or a pic or two to get readers interested about
everything've written. Just my opinion, it could make your website a little livelier.

THis is really great and I

Submitted by concrete fayetteville ar (not verified) on Wed, 2022-02-09 14:31.

THis is really great and I like to know more about RMI! Thanks!