Fix resolving of shapes files against local file system

Note that this is only relevant during tests, since resolution in bamm-cli or
library usage of the SDK will always resolve the shapes files from a jar.

Author: atextor

core/sds-aspect-meta-model-resolver/src/main/java/io/openmanufacturing/sds/aspectmodel/resolver/services/MetaModelUrls.java

@@ -2,7 +2,7 @@
  * Copyright (c) 2021 Robert Bosch Manufacturing Solutions GmbH
  *
  * See the AUTHORS file(s) distributed with this work for additional
- * information regarding authorship. 
+ * information regarding authorship.
  *
  * This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
@@ -13,12 +13,16 @@
 
 package io.openmanufacturing.sds.aspectmodel.resolver.services;
 
+import java.io.IOException;
 import java.net.URL;
+import java.util.List;
 import java.util.Optional;
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import com.google.common.collect.ImmutableList;
+
 import io.openmanufacturing.sds.aspectmetamodel.KnownVersion;
 
 /**
@@ -40,10 +44,36 @@ private MetaModelUrls() {
     */
    public static Optional<URL> url( final String part, final KnownVersion version, final String fileName ) {
       final String spec = String.format( "bamm/%s/%s/%s", part, version.toVersionString(), fileName );
-      final URL result = MetaModelUrls.class.getClassLoader().getResource( spec );
-      if ( result == null ) {
-         LOG.warn( "Could not resolve meta model resource {}", spec );
+      try {
+         final List<URL> urls = ImmutableList.copyOf( MetaModelUrls.class.getClassLoader().getResources( spec ).asIterator() );
+         if ( urls.size() == 1 ) {
+            return Optional.of( urls.get( 0 ) );
+         }
+         if ( urls.isEmpty() ) {
+            return nothingFound( spec );
+         }
+
+         // If multiple resources with the given spec are found:
+         // - return the one from the file system, if it exists
+         // - otherwise, the one from jar
+         // - otherwise, any of the found resources
+         URL jarUrl = null;
+         for ( final URL url : urls ) {
+            if ( url.getProtocol().equals( "file" ) ) {
+               return Optional.of( url );
+            }
+            if ( url.getProtocol().equals( "jar" ) ) {
+               jarUrl = url;
+            }
+         }
+         return Optional.of( jarUrl == null ? urls.get( 0 ) : jarUrl );
+      } catch ( final IOException e ) {
+         return nothingFound( spec );
       }
-      return Optional.ofNullable( result );
+   }
+
+   private static Optional<URL> nothingFound( final String spec ) {
+      LOG.warn( "Could not resolve meta model resource {}", spec );
+      return Optional.empty();
    }
 }