Add assembly check when pipeline trying to get stages (dotnet#1049)

src/csharp/Microsoft.Spark/ML/Feature/Base.cs

@@ -119,29 +119,4 @@ protected static T WrapAsType<T>(JvmObjectReference reference)
             return (T)constructor.Invoke(new object[] { reference });
         }
     }
-
-    /// <summary>
-    /// DotnetUtils is used to hold basic general helper functions that
-    /// are used within ML scope.
-    /// </summary>
-    internal class DotnetUtils
-    {
-        /// <summary>
-        /// Helper function for getting the exact class name from jvm object.
-        /// </summary>
-        /// <param name="jvmObject">The reference to object created in JVM.</param>
-        /// <returns>A string Tuple2 of constructor class name and method name</returns>
-        internal static (string, string) GetUnderlyingType(JvmObjectReference jvmObject)
-        {
-            var jvmClass = (JvmObjectReference)jvmObject.Invoke("getClass");
-            var returnClass = (string)jvmClass.Invoke("getTypeName");
-            string[] dotnetClass = returnClass.Replace("com.microsoft.azure.synapse.ml", "Synapse.ML")
-                .Replace("org.apache.spark.ml", "Microsoft.Spark.ML")
-                .Split(".".ToCharArray());
-            string[] renameClass = dotnetClass.Select(x => char.ToUpper(x[0]) + x.Substring(1)).ToArray();
-            string constructorClass = string.Join(".", renameClass);
-            string methodName = "WrapAs" + dotnetClass[dotnetClass.Length - 1];
-            return (constructorClass, methodName);
-        }
-    }
 }

src/csharp/Microsoft.Spark/ML/Feature/Bucketizer.cs

@@ -24,13 +24,13 @@ public class Bucketizer :
         IJavaMLWritable,
         IJavaMLReadable<Bucketizer>
     {
-        private static readonly string s_bucketizerClassName =
+        private static readonly string s_className =
             "org.apache.spark.ml.feature.Bucketizer";
 
         /// <summary>
         /// Create a <see cref="Bucketizer"/> without any parameters
         /// </summary>
-        public Bucketizer() : base(s_bucketizerClassName)
+        public Bucketizer() : base(s_className)
         {
         }
 
@@ -39,7 +39,7 @@ public Bucketizer() : base(s_bucketizerClassName)
         /// <see cref="Bucketizer"/> a unique ID
         /// </summary>
         /// <param name="uid">An immutable unique ID for the object and its derivatives.</param>
-        public Bucketizer(string uid) : base(s_bucketizerClassName, uid)
+        public Bucketizer(string uid) : base(s_className, uid)
         {
         }
 
@@ -163,7 +163,7 @@ public Bucketizer SetOutputCols(List<string> value) =>
         public static Bucketizer Load(string path) =>
             WrapAsBucketizer(
                 SparkEnvironment.JvmBridge.CallStaticJavaMethod(
-                    s_bucketizerClassName, "load", path));
+                    s_className, "load", path));
 
         /// <summary>
         /// Executes the <see cref="Bucketizer"/> and transforms the DataFrame to include the new

src/csharp/Microsoft.Spark/ML/Feature/CountVectorizer.cs

@@ -13,13 +13,13 @@ public class CountVectorizer :
         IJavaMLWritable,
         IJavaMLReadable<CountVectorizer>
     {
-        private static readonly string s_countVectorizerClassName =
+        private static readonly string s_className =
             "org.apache.spark.ml.feature.CountVectorizer";
 
         /// <summary>
         /// Creates a <see cref="CountVectorizer"/> without any parameters.
         /// </summary>
-        public CountVectorizer() : base(s_countVectorizerClassName)
+        public CountVectorizer() : base(s_className)
         {
         }
 
@@ -28,7 +28,7 @@ public CountVectorizer() : base(s_countVectorizerClassName)
         /// <see cref="CountVectorizer"/> a unique ID.
         /// </summary>
         /// <param name="uid">An immutable unique ID for the object and its derivatives.</param>
-        public CountVectorizer(string uid) : base(s_countVectorizerClassName, uid)
+        public CountVectorizer(string uid) : base(s_className, uid)
         {
         }
 
@@ -52,7 +52,7 @@ public override CountVectorizerModel Fit(DataFrame dataFrame) =>
         public static CountVectorizer Load(string path) =>
             WrapAsCountVectorizer((JvmObjectReference)
                 SparkEnvironment.JvmBridge.CallStaticJavaMethod(
-                    s_countVectorizerClassName, "load", path));
+                    s_className, "load", path));
 
         /// <summary>
         /// Gets the binary toggle to control the output vector values. If True, all nonzero counts

src/csharp/Microsoft.Spark/ML/Feature/CountVectorizerModel.cs

@@ -15,7 +15,7 @@ public class CountVectorizerModel :
         IJavaMLWritable,
         IJavaMLReadable<CountVectorizerModel>
     {
-        private static readonly string s_countVectorizerModelClassName =
+        private static readonly string s_className =
             "org.apache.spark.ml.feature.CountVectorizerModel";
 
         /// <summary>
@@ -24,7 +24,7 @@ public class CountVectorizerModel :
         /// <param name="vocabulary">The vocabulary to use</param>
         public CountVectorizerModel(List<string> vocabulary)
             : this(SparkEnvironment.JvmBridge.CallConstructor(
-                s_countVectorizerModelClassName, vocabulary))
+                s_className, vocabulary))
         {
         }
 
@@ -36,7 +36,7 @@ public CountVectorizerModel(List<string> vocabulary)
         /// <param name="vocabulary">The vocabulary to use</param>
         public CountVectorizerModel(string uid, List<string> vocabulary)
             : this(SparkEnvironment.JvmBridge.CallConstructor(
-                s_countVectorizerModelClassName, uid, vocabulary))
+                s_className, uid, vocabulary))
         {
         }
 
@@ -54,7 +54,7 @@ internal CountVectorizerModel(JvmObjectReference jvmObject) : base(jvmObject)
         public static CountVectorizerModel Load(string path) =>
             WrapAsCountVectorizerModel(
                 SparkEnvironment.JvmBridge.CallStaticJavaMethod(
-                    s_countVectorizerModelClassName, "load", path));
+                    s_className, "load", path));
 
         /// <summary>
         /// Gets the binary toggle to control the output vector values. If True, all nonzero counts

src/csharp/Microsoft.Spark/ML/Feature/FeatureHasher.cs

@@ -15,13 +15,13 @@ public class FeatureHasher :
         IJavaMLWritable,
         IJavaMLReadable<FeatureHasher>
     {
-        private static readonly string s_featureHasherClassName =
+        private static readonly string s_className =
             "org.apache.spark.ml.feature.FeatureHasher";
 
         /// <summary>
         /// Creates a <see cref="FeatureHasher"/> without any parameters.
         /// </summary>
-        public FeatureHasher() : base(s_featureHasherClassName)
+        public FeatureHasher() : base(s_className)
         {
         }
 
@@ -30,7 +30,7 @@ public FeatureHasher() : base(s_featureHasherClassName)
         /// <see cref="FeatureHasher"/> a unique ID.
         /// </summary>
         /// <param name="uid">An immutable unique ID for the object and its derivatives.</param>
-        public FeatureHasher(string uid) : base(s_featureHasherClassName, uid)
+        public FeatureHasher(string uid) : base(s_className, uid)
         {
         }
 
@@ -48,7 +48,7 @@ internal FeatureHasher(JvmObjectReference jvmObject) : base(jvmObject)
         public static FeatureHasher Load(string path) =>
             WrapAsFeatureHasher(
                 SparkEnvironment.JvmBridge.CallStaticJavaMethod(
-                    s_featureHasherClassName,
+                    s_className,
                     "load",
                     path));
 

src/csharp/Microsoft.Spark/ML/Feature/HashingTF.cs

@@ -21,13 +21,13 @@ public class HashingTF :
         IJavaMLWritable,
         IJavaMLReadable<HashingTF>
     {
-        private static readonly string s_hashingTfClassName =
+        private static readonly string s_className =
             "org.apache.spark.ml.feature.HashingTF";
 
         /// <summary>
         /// Create a <see cref="HashingTF"/> without any parameters
         /// </summary>
-        public HashingTF() : base(s_hashingTfClassName)
+        public HashingTF() : base(s_className)
         {
         }
 
@@ -36,7 +36,7 @@ public HashingTF() : base(s_hashingTfClassName)
         /// <see cref="HashingTF"/> a unique ID
         /// </summary>
         /// <param name="uid">An immutable unique ID for the object and its derivatives.</param>
-        public HashingTF(string uid) : base(s_hashingTfClassName, uid)
+        public HashingTF(string uid) : base(s_className, uid)
         {
         }
 
@@ -52,7 +52,7 @@ internal HashingTF(JvmObjectReference jvmObject) : base(jvmObject)
         public static HashingTF Load(string path) =>
             WrapAsHashingTF(
                 SparkEnvironment.JvmBridge.CallStaticJavaMethod(
-                    s_hashingTfClassName, "load", path));
+                    s_className, "load", path));
 
         /// <summary>
         /// Gets the binary toggle that controls term frequency counts

src/csharp/Microsoft.Spark/ML/Feature/IDF.cs

@@ -22,12 +22,12 @@ public class IDF :
         IJavaMLWritable,
         IJavaMLReadable<IDF>
     {
-        private static readonly string s_IDFClassName = "org.apache.spark.ml.feature.IDF";
+        private static readonly string s_className = "org.apache.spark.ml.feature.IDF";
 
         /// <summary>
         /// Create a <see cref="IDF"/> without any parameters
         /// </summary>
-        public IDF() : base(s_IDFClassName)
+        public IDF() : base(s_className)
         {
         }
 
@@ -36,7 +36,7 @@ public IDF() : base(s_IDFClassName)
         /// <see cref="IDF"/> a unique ID
         /// </summary>
         /// <param name="uid">An immutable unique ID for the object and its derivatives.</param>
-        public IDF(string uid) : base(s_IDFClassName, uid)
+        public IDF(string uid) : base(s_className, uid)
         {
         }
 
@@ -103,7 +103,7 @@ public override IDFModel Fit(DataFrame source) =>
         public static IDF Load(string path)
         {
             return WrapAsIDF(
-                SparkEnvironment.JvmBridge.CallStaticJavaMethod(s_IDFClassName, "load", path));
+                SparkEnvironment.JvmBridge.CallStaticJavaMethod(s_className, "load", path));
         }
 
         /// <summary>

src/csharp/Microsoft.Spark/ML/Feature/IDFModel.cs

@@ -17,13 +17,13 @@ public class IDFModel :
         IJavaMLWritable,
         IJavaMLReadable<IDFModel>
     {
-        private static readonly string s_IDFModelClassName =
+        private static readonly string s_className =
             "org.apache.spark.ml.feature.IDFModel";
 
         /// <summary>
         /// Create a <see cref="IDFModel"/> without any parameters
         /// </summary>
-        public IDFModel() : base(s_IDFModelClassName)
+        public IDFModel() : base(s_className)
         {
         }
 
@@ -32,7 +32,7 @@ public IDFModel() : base(s_IDFModelClassName)
         /// <see cref="IDFModel"/> a unique ID
         /// </summary>
         /// <param name="uid">An immutable unique ID for the object and its derivatives.</param>
-        public IDFModel(string uid) : base(s_IDFModelClassName, uid)
+        public IDFModel(string uid) : base(s_className, uid)
         {
         }
 
@@ -96,7 +96,7 @@ public static IDFModel Load(string path)
         {
             return WrapAsIDFModel(
                 SparkEnvironment.JvmBridge.CallStaticJavaMethod(
-                    s_IDFModelClassName, "load", path));
+                    s_className, "load", path));
         }
 
         /// <summary>

src/csharp/Microsoft.Spark/ML/Feature/NGram.cs

@@ -19,13 +19,13 @@ public class NGram :
         IJavaMLWritable,
         IJavaMLReadable<NGram>
     {
-        private static readonly string s_nGramClassName =
+        private static readonly string s_className =
             "org.apache.spark.ml.feature.NGram";
 
         /// <summary>
         /// Create a <see cref="NGram"/> without any parameters.
         /// </summary>
-        public NGram() : base(s_nGramClassName)
+        public NGram() : base(s_className)
         {
         }
 
@@ -35,7 +35,7 @@ public NGram() : base(s_nGramClassName)
         /// </summary>
         /// <param name="uid">An immutable unique ID for the object and its derivatives.
         /// </param>
-        public NGram(string uid) : base(s_nGramClassName, uid)
+        public NGram(string uid) : base(s_className, uid)
         {
         }
 
@@ -123,7 +123,7 @@ public override StructType TransformSchema(StructType value) =>
         public static NGram Load(string path) =>
             WrapAsNGram(
                 SparkEnvironment.JvmBridge.CallStaticJavaMethod(
-                    s_nGramClassName,
+                    s_className,
                     "load",
                     path));
 

src/csharp/Microsoft.Spark/ML/Feature/Pipeline.cs

@@ -3,10 +3,11 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
-using System.Reflection;
 using Microsoft.Spark.Interop;
 using Microsoft.Spark.Interop.Ipc;
 using Microsoft.Spark.Sql;
+using Microsoft.Spark.Utils;
+using System.Collections.Generic;
 
 namespace Microsoft.Spark.ML.Feature
 {
@@ -26,12 +27,12 @@ public class Pipeline :
         IJavaMLWritable,
         IJavaMLReadable<Pipeline>
     {
-        private static readonly string s_pipelineClassName = "org.apache.spark.ml.Pipeline";
+        private static readonly string s_className = "org.apache.spark.ml.Pipeline";
 
         /// <summary>
         /// Creates a <see cref="Pipeline"/> without any parameters.
         /// </summary>
-        public Pipeline() : base(s_pipelineClassName)
+        public Pipeline() : base(s_className)
         {
         }
 
@@ -40,7 +41,7 @@ public Pipeline() : base(s_pipelineClassName)
         /// <see cref="Pipeline"/> a unique ID.
         /// </summary>
         /// <param name="uid">An immutable unique ID for the object and its derivatives.</param>
-        public Pipeline(string uid) : base(s_pipelineClassName, uid)
+        public Pipeline(string uid) : base(s_className, uid)
         {
         }
 
@@ -57,24 +58,34 @@ internal Pipeline(JvmObjectReference jvmObject) : base(jvmObject)
         /// <returns><see cref="Pipeline"/> object</returns>
         public Pipeline SetStages(JavaPipelineStage[] value) =>
             WrapAsPipeline((JvmObjectReference)SparkEnvironment.JvmBridge.CallStaticJavaMethod(
-                "org.apache.spark.mllib.api.dotnet.MLUtils", "setPipelineStages",
-                Reference, value.ToJavaArrayList()));
+                "org.apache.spark.mllib.api.dotnet.MLUtils",
+                "setPipelineStages",
+                Reference,
+                value.ToJavaArrayList()));
 
         /// <summary>
         /// Get the stages of pipeline instance.
         /// </summary>
         /// <returns>A sequence of <see cref="JavaPipelineStage"/> stages</returns>
         public JavaPipelineStage[] GetStages()
         {
-            JvmObjectReference[] jvmObjects = (JvmObjectReference[])Reference.Invoke("getStages");
-            JavaPipelineStage[] result = new JavaPipelineStage[jvmObjects.Length];
+            var jvmObjects = (JvmObjectReference[])Reference.Invoke("getStages");
+            var result = new JavaPipelineStage[jvmObjects.Length];
+            Dictionary<string, Type> classMapping = JvmObjectUtils.ConstructJavaClassMapping(
+                typeof(JavaPipelineStage),
+                "s_className");
+
             for (int i = 0; i < jvmObjects.Length; i++)
             {
-                (string constructorClass, string methodName) = DotnetUtils.GetUnderlyingType(jvmObjects[i]);
-                Type type = Type.GetType(constructorClass);
-                MethodInfo method = type.GetMethod(methodName, BindingFlags.NonPublic | BindingFlags.Static);
-                result[i] = (JavaPipelineStage)method.Invoke(null, new object[] { jvmObjects[i] });
+                if (JvmObjectUtils.TryConstructInstanceFromJvmObject(
+                    jvmObjects[i],
+                    classMapping,
+                    out JavaPipelineStage instance))
+                {
+                    result[i] = instance;
+                }                   
             }
+
             return result;
         }
 
@@ -91,7 +102,7 @@ override public PipelineModel Fit(DataFrame dataset) =>
         /// <param name="path">The path the previous <see cref="Pipeline"/> was saved to</param>
         /// <returns>New <see cref="Pipeline"/> object, loaded from path.</returns>
         public static Pipeline Load(string path) => WrapAsPipeline(
-            SparkEnvironment.JvmBridge.CallStaticJavaMethod(s_pipelineClassName, "load", path));
+            SparkEnvironment.JvmBridge.CallStaticJavaMethod(s_className, "load", path));
 
         /// <summary>
         /// Saves the object so that it can be loaded later using Load. Note that these objects