Behavior differ between running application in IntelliJ and from jar - maven

Question

I have written an application using Jetty as a server. I wish to package my application into a .jar, so I may put it in a Docker container later on.
When I run my application through IntelliJ, everything seems to be working as it should, and I can reach my index.html from localhost:2222. However, when I package my application (using mvn clean compile assembly:single) and run my jar by typing java -jar myapplication.jar in the shell, my index.html on localhost:2222 returns HTTP Error 404.
My App.java:
public class App {
public static void main( String[] args ) throws Exception {
ResourceConfig config = new ResourceConfig();
config.packages("mypackage");
ServletHolder servlet = new ServletHolder(new ServletContainer(config));
Server server = new Server(2222);
ResourceHandler handler = new ResourceHandler();
handler.setBaseResource(org.eclipse.jetty.util.resource.Resource
.newClassPathResource("index.html"));
ServletContextHandler context = new ServletContextHandler(server, "/*");
context.addServlet(servlet, "/*");
HandlerList handlers = new HandlerList();
handlers.addHandler(handler);
handlers.addHandler(context);
server.setHandler(handlers);
try {
server.start();
server.join();
} finally {
server.destroy();
}
}
}
When running the application in IntelliJ and as jar, I get the following output (may be of interest?):
2015-11-06 09:25:00.991:INFO::main: Logging initialized #279ms
2015-11-06 09:25:01.238:WARN:oejsh.ContextHandler:main: o.e.j.s.ServletContextHandler#490d6c15{/,null,null} contextPath ends with /*
2015-11-06 09:25:01.238:WARN:oejsh.ContextHandler:main: Empty contextPath
2015-11-06 09:25:01.250:INFO:oejs.Server:main: jetty-9.2.3.v20140905
Nov 06, 2015 9:25:01 AM org.glassfish.jersey.server.ApplicationHandler initialize
INFO: Initiating Jersey application, version Jersey: 2.7 2014-03-12 18:11:31...
2015-11-06 09:25:02.294:INFO:oejsh.ContextHandler:main: Started o.e.j.s.ServletContextHandler#490d6c15{/,null,AVAILABLE}
2015-11-06 09:25:02.306:INFO:oejs.ServerConnector:main: Started ServerConnector#268f106e{HTTP/1.1}{0.0.0.0:2222}
2015-11-06 09:25:02.306:INFO:oejs.Server:main: Started #1688ms
I am not posting my file of Jersey-methods, since I don't think it is relevant for my question.
So, what is the magic of packaging this up to a jar that can recognize my index.html at localhost:2222? Is it some environment settings in IntelliJ?
Cheers

Answer 1

First of all, don't mix ResourceHandler and ServletContextHandler, you are duplicating static content effort (3 times over with Jersey in play) and will get unreliable results.
Drop the ResourceHandler, set the required ServletContextHandler.setBaseResource(), and add a DefaultServlet to your context.
// Figure out what path to serve content from
ClassLoader cl = App.class.getClassLoader();
// We look for a file, as ClassLoader.getResource() is not
// designed to look for directories (we resolve the directory later)
URL f = cl.getResource("static-root/index.html");
if (f == null)
{
throw new RuntimeException("Unable to find resource directory");
}
// Resolve file to directory
URI webRootUri = f.toURI().resolve("./").normalize();
System.err.println("Main Base Resource is " + webRootUri);
// Setup the basic application "context" for this application at "/"
// This is also known as the handler tree (in jetty speak)
ServletContextHandler context = new ServletContextHandler(ServletContextHandler.SESSIONS);
context.setContextPath("/");
context.setBaseResource(Resource.newResource(webRootUri));
server.setHandler(context);
// Jersey setup
ResourceConfig config = new ResourceConfig();
config.packages("mypackage");
context.addServlet(new ServletHolder(new ServletContainer(config)), "/*");
// Lastly, the default servlet for root content (always needed, to satisfy servlet spec)
// It is important that this is last.
ServletHolder holderDef = new ServletHolder("default",DefaultServlet.class);
holderDef.setInitParameter("dirAllowed","true");
context.addServlet(holderDef,"/");
Note: since you setup Jersey at the url-pattern /* you should know that Jersey is responsible for serving all static content, not Jetty.