JRebel alternative ?

I’m working now more and more faster developing a vaadin application. but one thing drives me crazy.
i spend so much time to wait each time i can reload the browser. because i’m new to vaadin i need to change something smal and neet to see the result.

is there any open source alternative for jrebel? what do you use? how do you handle this issue?


last year I looked for a JRebel alternative and I just didn’t find any with the same level of integration as JRebel. I believe I found one OPen Source project I forgot the name of.
JRebel works fine with Vaadin and I am very happy with that

i belive you, that jrebel works fine with vaadin :slight_smile: no doubt.
but for a student or a freetime developer are $265/per jear to much. that’s the reason why i search for an alternative.


There are ‘OSS’ and ‘Social’ licenses of JRebel available just for this purpose. It just requires that the software is either open-sourced or strictly non-commercial. See the Free options on
this page


Although I agree with you, as a freelancer myself i try to stay in the OSS world (and give back to the OSS world) however sometimes there are tools that are really time savers and no good alternatives in the OSS world. JRebel as one of the tools that has a very short ROI, even with it’s price of 285.

I recently fall on Dynamic Code Evolution VM (http://ssw.jku.at/dcevm/). Maybe it can do the tricks.

Did you try it out? Would be interesting to hear your experiences.

is related (JEP by the same
author: Thomas Würthinger
). And maybe
project is something that will eventually replace this work - at Thomas is currently working in the project.

That said - JRebel seems to the be only real option at the moment.

No, just have seen the website for know. But I would also be interested to hear any experience about it.

All in all, the DCEVM project seems to be dead. No activity on the project for a long time.

I agree that the website is a bit outdated, and the binary is not built from the latest source which support the new jdk 1.7. So unless you’re using jdk 1.6, it will be a little tricky to get it work.

But once you get it set up, using it is very easy and straight-forward, and the gain in productivity is well worth the effort. I was able to make it work with jdk 1.7 and I was so excited I decided to create a new blog just to write a
setup guide
for this great tool.

@Isabelle, please check it out and share with us how it works out for you.


Hello All,

If you are using Ant to build your application(like ear) you can use something like
(https://code.google.com/p/hotswap/) I have customised it a bit and used it in my project. It is able to reflect all your chages at the method level. I have used it successfully. But faced issues when, I add or create a new Method. Though it is dead project, I have tried and tested it with Oracle JDK1.6

DCEVM is still alive :-). Take a look at
Hotswap Agent

  • Framework support - Spring, Hibernate, Logback, Jetty, Tomcat, JSF, … Unfortunatelly there is not a plugin to support Vaadin specifics yet, however, it should be easy for someone who knows Vaadin internals.
  • Documentation how to setup DCEVM and precompiled binaries for Java 1.7
  • Load classes and resources from various location (allow reload of classes from dependent projects)
  • Open source and free

Just to inform, hotswap agent works fine with jdk8, Vaadin 7.4.8, Eclipse luna SR2, Tomcat8 and Maven.
Follow this link to setup your environment:


Hmm can you confirm it works with Tomcat 8? I read somewhere that there were issues and it still wasn’t supported
I’m getting errors when deploying a Spring/Vaadin webapp. This one in the beginning and then several BeanCreationException later (using jdk 1.8.0_66)
InvocationTargetException in transform method on plugin ‘class org.hotswap.agent.plugin.tomcat.TomcatPlugin’ class ‘org/apache/catalina/loader/WebappClassLoader’