Hot deploy on JBoss - how do I make JBoss "see" the change?
I am developing a Java EE application that I deploy over and over again on a local JBoss installation during development. I want to speed up the build by hot deploying my application straight into [JBOSS]/server/default/deploy/myApp
It seems to work - but there also seems to be a somewhat arbitrary delay between the hard deploy and when JBoss starts using the new classes. I am not very familiar with JBoss, but I assume it caches classes, and that this is what causes the problem.
Am I correct, and if so, how do I make JBoss flush it's cache?
Solution 1:
I had the same problem in my bundle: (Eclipse IDE + JBoss server adapter) + JBoss AS 7.0.1 (community project).
My solution is very simple - you should go to JBoss administrative panel (by default localhost:9990), there in profile settings open Core - Deployment Scanners. Turn on Autodeploy-Exploded (set to true), and by your wishes you can set scanner time (by default 5000 ms) to appropriate for your (I set to 2000, for more fast incremental publish in Eclipse when I make changes to projects). That's it. Now JBoss makes HOT deploy not only for HTML (JSF, XHTML and so on) files, but also takes care of POJO classes (beans and so on) files.
Solution 2:
Unfortunately, it's not that easy. There are more complicated things behind the scenes in JBoss (most of them ClassLoader related) that will prevent you from HOT-DEPLOYING your application.
For example, you are not going to be able to HOT-DEPLOY if some of your classes signatures change.
So far, using MyEclipse IDE (a paid distribution of Eclipse) is the only thing I found that does hot deploying quite successfully. Not 100% accuracy though. But certainly better than JBoss Tools, Netbeans or any other Eclipse based solution.
I've been looking for free tools to accomplish what you've just described by asking people in StackOverflow if you want to take a look.
Solution 3:
You should try JRebel, which does the hot deploy stuff pretty well. A bit expensive, but worth the money. They have a trial version.
Solution 4:
Just my two cents:
Cold deployment is the way of deploying an application when you stop it (or stop the whole server), then you install the new version, and finally restart the application (or start the whole server). It's suitable for official production deployments, but it would be horrible slow to do this during development. Forget about rapid development if you are doing this.
Auto deployment is the ability the server has to re-scan periodically for a new EAR/WAR and deploy it automagically behind the scenes for you, or for the IDE (Eclipse) to deploy automagically the whole application when you make changes to the source code. JBoss does this, but JBoss's marketing department call this misleadingly "hot deployment". An auto deployment is not as slow compared to a cold deployment, but is really slow compared to a hot deployment.
Hot deployment is the ability to deploy behind the scenes "as you type". No need to redeploy the whole application when you make changes. Hot deployment ONLY deploys the changes. You change a Java source code, and voila! it's running already. You never noticed it was deploying it. JBoss cannot do this, unless you buy for JRebel (or similar) but this is too much $$ for me (I'm cheap).
Now my "sales pitch" :D
What about using Tomcat during development? Comes with hot deployment all day long... for free. I do that all the time during development and then I deploy on WebSphere, JBoss, or Weblogic. Don't get me wrong, these three are great for production, but are really AWFUL for rapid-development on your local machine. Development productivity goes down the drain if you use these three all day long.
In my experience, I stopped using WebSphere, JBoss, and Weblogic for rapid development. I still have them installed in my local environment, though, but only for the occasional test I may need to run. I don't pay for JRebel all the while I get awesome development speed. Did I mention Tomcat is fully compatible with JBoss?
Tomcat is free and not only has auto-deployment, but also REAL hot deployment (Java code, JSP, JSF, XHTML) as you type in Eclipse (Yes, you read well). MYKong has a page (https://www.mkyong.com/eclipse/how-to-configure-hot-deploy-in-eclipse/) with details on how to set it up.
Did you like my sales pitch?
Cheers!