I've done a quick google search on this and i've come up with the following.
When you run your project you recieve the 404.
The problem is the service is sent incompletely to your JBoss Application server, so when you try to get on it the host returns a 404 to you as it can't return that service to you. This is caused in your configuration from what I gather.
Now for the solution:
Create a Maven build by right clicking > run as > build. Set your goals as "clean package jboss-as:deploy", then simply click Run and wait
Next preview the project by running it on the server, this fixed the issue for the person in need. I hope it helps you too.
Credit goes to Google for this one.