ClassCastException in ImportResolver.resolveImports() when using custom ResourceManager

[Andre Gillet]

Hello,

Found in 3.4.1 but issue still seems to exist.  We have a custom 
ResourceManager which implements the ResourceManager interface.  Following code 
assumes that aResourceManager will always be a ResourceManager_impl.

Method signature defines ResourceManager aResourceManager:

https://github.com/apache/uima-uimaj/blob/81587d2e6894655af3b07b347a976fd92d8f7bf0/uimaj-core/src/main/java/org/apache/uima/resource/metadata/impl/ImportResolver.java#L142-L144

  private void resolveImports(DescriptorAdapter<DESCRIPTOR, COLLECTIBLE> 
aWrapper,
          Set<String> aAlreadyVisited, Map<Key, COLLECTIBLE> 
aAllCollectedObjects,
          Deque<String> aStack, ResourceManager aResourceManager) throws 
InvalidXMLException {

Casting aResourceManager to ResourceManager_impl causes ClassCastException:

https://github.com/apache/uima-uimaj/blob/81587d2e6894655af3b07b347a976fd92d8f7bf0/uimaj-core/src/main/java/org/apache/uima/resource/metadata/impl/ImportResolver.java#L160

    Map<String, XMLizable> importCache = ((ResourceManager_impl) 
aResourceManager).getImportCache();

Thanks,

Andre