Deploying a Jersey based web app to WildFly 8 (part 1)

I’ve been resuscitating a personal Amateur Radio related project from a few years back that I previously had hosted on RedHat’s OpenShift. It was previously deployed on WildFly 8, so before I start making changes I want to get it deployed again locally on WildFly 8.

First up I got this error:

org.jboss.weld.exceptions.DeploymentException: WELD-001408: Unsatisfied dependencies for type ServiceLocator with qualifiers @Default at injection point [BackedAnnotatedField] @Inject private org.glassfish.jersey.internal.inject.ContextInjectionResolver.serviceLocator

This error appears to be pretty common. From the suggestions posted in reply to a similar post to WildFly forum here, the suggestion was to include Glassfish dependencies. I never had these included before, so not sure why I need these now, but these did the job:

<!-- kh added for error: WELD-001408: Unsatisfied dependencies for type Set<Service> with qualifiers @Default -->

<!-- kh: added per: -->


The odd thing is if I deploy to WildFly 8.2 I don’t get this error or need these additional dependencies. Anyway, all set for now. I just tested deploying to 17.0.1 with no additional changes needed either.

WildFly Swarm microservice development: JAX-RS app deployed to a Docker container

WildFly Swarm is an interesting approach to the ‘small is good’ current trend that is ignoring the traditional, overly large Java EE App Servers, and instead deploying self-contained, executable Jars without needing a whole App Server to execute.

Rather than requiring the whole Java EE stack, WildFly Swarm lets you chose only the implementations of the parts that your service needs to execute. Need JAX-RS? Then pull it in via a Maven dependency. Need JPA? Pull that in too. Any other required transitive dependencies are automatically pulled in via Maven. Pulling in JAX-RS also requires a Servlet container and APIs, but this is pulled in for you via Maven transitive dependencies. The end result is a self-contained, packaged Jar that contains everything it needs to run with a ‘java -jar’ command.

I’ve been spending some time recently looking at getting Weblogic Portal 10.3.6 running in a Docker container (check my work in progress changes on GitHub here). As EE containers go, it’s big. It’s heavy. If you want to describe anything as a monolith, then this is your perfect example. So switching gears I wanted to go to the other extreme and look at how you would build a lightweight Java based service, and WildfFly Swarm looked pretty interesting.

I attended one of the sessions at JavaOne this year giving an intro to Swarm, so it’s been on my todo list to take a look.

Getting started with Swarm is actually pretty easy, as it’s all driven by Maven dependencies and plugins. There’s an easy to follow tutorial here. The example apps showing different WildFly components packaged using Swarm are also worth a look here.

I worked through the examples putting together a JAX-RS helloworld app, and also a Dockerfile to package and deploy it to a Docker container. It was actually pretty easy, and my app ended up looking much like the provided examples.

My example JAX-RS resource is pretty simple, nothing complicated here:

If you’re looking for the different WildFly services that you can package with Swarm, browsing the mvnrepository is a good place to start to quickly grab the mvn deps, or browse the examples or source.

For the Maven war and wildfly-storm plugins:


Next, adding a dependency for the WildFly Swarm JAX-RS:


To build the self-contained executable Jar, build with ‘mvn package’ – this will build the app as normal to target, but also include a *-swarm.jar – this the self-contained Jar containing all the WildFly dependencies, and can be run standalone with ‘java -jar helloworld-swarm-0.0.1-SNAPSHOT-swarm.jar’

Building a Docker container

Given that we’ve now got a simple, single, self-contained Jar, deploying this into a Docker container is also pretty easy as we have no other dependencies to worry about (we just need a JVM).

An example Dockerfile would look like (scroll to the right):

FROM java:openjdk-8-jdk
ADD target/helloworld-swarm-0.0.1-SNAPSHOT-swarm.jar /opt/helloworld-swarm.jar
ENTRYPOINT ["java", "-jar", "/opt/helloworld-swarm.jar"]

All we’re doing here is:
1. Creating an image based on the official openjdk image from DockerHub

2. Adding our built WildFly Swarm jar containing our app into /opt in the image

3. Exposing port 8080

4. Defining the Entrypoint that executes when the container starts

To create an image based on this Dockerfile:

docker build -t helloworld .

To start a container based on this image:

docker run -d -p 8080:8080 imageid

… this creates a new container based on the new container, runs it as a daemon, with port 8080 in the container exposed to 8080 on the host. Done!

Hit the URL of our endpoint using the IP of the running Docker-Machine:

To watch the logs of the running container, do:

docker logs -f containerid

In this case you see the output as the WildFly Undertow Servlet container starts up, and initializes our JAX-RS based app:

Pretty simple! We’ve got a minimal WildFly server starting up inside a Docker container in about 10s, and our app deploying in 2s. That’s pretty good if you ask me 🙂


Connecting to the WildFly web admin console on OpenShift

OpenShift limits the ports that are publicly accessible from your running cartridges. To connect to the WildFly web console on port 9990, you can use the port forwarding:

rhc port-forward yourappname

When it reports the list of forwarded ports, connect to localhost:9990 and logon with your admin user/password.

More info here.

Hibernate OGM / JAX-RS / JAX-WS redeployment issue on WildFly8.2: java.lang.NoSuchMethodException: org.objectweb.asm.MethodWriter.visitLabel

I’ve been struggling with failing redeploys on WildFly8.2 while I’m developing my app. If the app is deployed, on first server start it starts up fine, but then if I redeploy some code changes I get this NoSuchMethodException in the asm library, suggesting I’ve got some conflict of versions of the asm library used by my app:

Caused by: java.lang.NoSuchMethodException: org.objectweb.asm.MethodWriter.visitLabel(org.objectweb.asm.Label)
 at java.lang.Class.getMethod( [rt.jar:1.8.0_20]
 at org.apache.cxf.common.util.ReflectionInvokationHandler.invoke(
 ... 28 more

Luckily I came across this post with the same error, putting me on the right direction about the possibility of my app being packaged with a conflicting version of asm. Looking at a ‘mvn dependency:tree’ on my app, I could see asm being pulled in from my use of Hibernate OGM and Jersey as transitive dependencies.

Despite trying to add excludes to not get asm included in the packaging of my app, I eventually gave up and decided to just remove my luckily minimal use of Hibernate OGM. I think the issue was caused my OGM’s deployment of modules onto the WildFly server, one of which was asm. After I had removed OGM from my app, removed the modules, I was back to speedy redeploys of my app.

I’m sure there’s a way to get OGM to deploy happily, or maybe I had just ran across an asm version conflict with other libraries my app is using (Jersey?), but I don’t have time right now to deal with it. Another project for another day 🙂