Add bridge to cast ObjectInspector from UDF class loader to main class loader (#73)

Author: wmoustafa

coral-hive/src/main/java/com/linkedin/coral/hive/hive2rel/functions/ArtifactsResolver.java

@@ -40,7 +40,7 @@ public class ArtifactsResolver {
   private final Ivy _ivyInstance;
   public ArtifactsResolver() {
     // Ivy spews a lot of junk on the console. Hiding it
-    Message.setDefaultLogger(new DefaultMessageLogger(getIvyLogLevel()));
+    Message.setDefaultLogger(new DefaultMessageLogger(Message.MSG_ERR));
     final IvySettings settings = setupIvySettings();
     _ivyInstance = Ivy.newInstance(settings);
   }

coral-hive/src/main/java/com/linkedin/coral/hive/hive2rel/functions/HiveGenericUDFReturnTypeInference.java

@@ -46,9 +46,10 @@ public RelDataType inferReturnType(SqlOperatorBinding sqlOperatorBinding) {
     try {
       Class dynamicallyLoadedUdfClass = getDynamicallyLoadedUdfClass();
       return getRelDataType(
-          (ObjectInspector) dynamicallyLoadedUdfClass
-              .getMethod("initialize", getDynamicallyLoadedObjectInspectorArrayClass()).invoke(
-                  dynamicallyLoadedUdfClass.newInstance(), getDynamicallyLoadedObjectInspectors(inputObjectInspectors)),
+          getContextObjectInspector(
+              dynamicallyLoadedUdfClass.getMethod("initialize", getDynamicallyLoadedObjectInspectorArrayClass()).invoke(
+                  dynamicallyLoadedUdfClass.newInstance(),
+                  new Object[] { getDynamicallyLoadedObjectInspectors(inputObjectInspectors) })),
           sqlOperatorBinding.getTypeFactory());
     } catch (NoSuchMethodException e) {
       throw new RuntimeException(
@@ -146,7 +147,7 @@ private final ObjectInspector getContextObjectInspector(Object oi) {
       return TypeInfoUtils
           .getStandardJavaObjectInspectorFromTypeInfo(TypeInfoUtils.getTypeInfoFromTypeString(typeInfoString));
     } catch (ClassNotFoundException | NoSuchMethodException | InvocationTargetException | IllegalAccessException e) {
-      throw new RuntimeException("Could not get Context ObjectInspector from UDF ObjectInspector.", e);
+      throw new RuntimeException("Could not get Context ObjectInspector from dynamically loaded ObjectInspector.", e);
     }
   }