migratory-core/src/main/java/com/nesscomputing/migratory/loader/JarLoader.java
@Override
    public String loadFile(final URI fileUri) throws IOException
    {
        return Resources.toString(fileUri.toURL(), charset);
    }
@Override
    public String loadFile(final URI fileUri) throws IOException
    {
        return Resources.toString(fileUri.toURL(), charset);
    }
This method loads a file from a file:/... URI. This is probably not what you are looking for.