The system cannot find the file specified while starting a windows service from a Java App using Apache Commons Daemon

I have the following file structure from Eclipse for my Java app which I turned into a windows service using Apache Commons Daemon.

SubscriberACD
    /Maven Dependencies
    /src/main/java
        /org.SubscriberACD
            /Subscriber.java
    /src/test/java
    /JRE System Librar
    /src
    /target
    config.xml
    pom.xml

In Subscriber.java, here is where the string is defined:

    private static final String CONFIG_FILE = "config.xml";

Here is the code snippet to read from the xml file (based off of this post: Java: How to read and write xml files?):

   Document document;
   DocumentBuilderFactory doc_builder_factory = DocumentBuilderFactory.newInstance();

   try {
       DocumentBuilder doc_builder = doc_builder_factory.newDocumentBuilder();
       document = doc_builder.parse(CONFIG_FILE);

My file directory for the service looks like this:

E:\SubscriberACD
     \bin
        \subscriberACD.exe
        \subscriberACDw.exe
     \classes
        \org
           \SubscriberACD
               \Subscriber.class
               \config.xml
        \3rdpartyjarfiles
        \SubscriberACD.jar
     \logs

Notice how I stuck config.xml under SubscriberACD under classes just to try it out. But it didn't work. Also worth noting that I also exported my project as a SubscriberACD.jar and put that under \classes folder. From eclipse, it does look like config.xml is also being packaged in that jar. I get the following error when I try to start my windows service:

2016-04-16 15:08:27 Commons Daemon procrun stderr initialized
Exception in thread "main" n\config.xml (The system cannot find the file specified)
java.lang.NumberFormatException: For input string: "null"
    at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
    at java.lang.Integer.parseInt(Integer.java:492)
    at java.lang.Integer.parseInt(Integer.java:527)
    at zmq.TcpAddress.resolve(TcpAddress.java:105)
    at zmq.Address.resolve(Address.java:98)
    at zmq.SocketBase.connect(SocketBase.java:510)
    at org.zeromq.ZMQ$Socket.connect(ZMQ.java:1246)
    at org.SubscriberACD.Subscriber.start(Subscriber.java:114)
    at org.SubscriberACD.Subscriber.windowsService(Subscriber.java:61)

Was there some additional configuration that I missed?

Try this: Put the file config.xml directly into the classes folder:

E:\SubscriberACD\classes\config.xml

Then in Subscriber.java try to load the file like this:

Document document;
DocumentBuilderFactory doc_builder_factory = DocumentBuilderFactory.newInstance();
try {
    DocumentBuilder doc_builder = doc_builder_factory.newDocumentBuilder();
    try(InputStream instream = Thread.currentThread().getContextClassLoader().getResourceAsStream("config.xml")) {
        document = doc_builder.parse(instream);
    }
} catch(SAXException | ParserConfigurationException e) {
    throw new RuntimeException(e);
}