Fix for issue UiPath#31 on empty array

.gitignore

@@ -3,3 +3,4 @@
 ################################################################################
 
 /.vs
+/Activities/Java/Invoke/out

Activities/Java/Invoke/src/com/uipath/dotnetjavatypes/ArrayTypeSerializer.java

@@ -19,8 +19,10 @@ public class ArrayTypeSerializer implements TypeSerializerInterface {
 
     public JavaObject DeserializeToJavaObject(JSONObject obj) {
         JSONArray array = null;
+        String runtimeArrayType = null;
         try {
             array = obj.getJSONArray("value");
+            runtimeArrayType = obj.getString("runtime_arrayType");
         }
         catch (JSONException e) {  }
 
@@ -29,6 +31,9 @@ public JavaObject DeserializeToJavaObject(JSONObject obj) {
         }
         Class<?> arrayType = getArrayType(context, array);
         int length = array.length();
+        if (array.length() == 0){
+            return EmptyTypeSerializer.DeserializeToJavaObject(runtimeArrayType);
+        }
         Object result = Array.newInstance(arrayType, length);
 
         for (int i = 0; i < length; ++i) {

Activities/Java/Invoke/src/com/uipath/dotnetjavatypes/EmptyTypeSerializer.java

@@ -3,12 +3,37 @@
 import com.uipath.instance.ObjectInstance;
 import org.json.JSONObject;
 
+import java.lang.reflect.Array;
+
 public class EmptyTypeSerializer implements TypeSerializerInterface {
 
     public JavaObject DeserializeToJavaObject(JSONObject obj) {
         return new JavaObject(new EmptyClass(), EmptyClass.class);
     }
 
+    public static JavaObject DeserializeToJavaObject(String type){
+        if ("System.Int32[]".equals(type)) {
+            return new JavaObject(new int[0], Array.newInstance(int.class, 0).getClass());
+        } else if ("System.Boolean[]".equals(type)) {
+            return new JavaObject(new boolean[0], Array.newInstance(boolean.class, 0).getClass());
+        } else if ("System.Byte[]".equals(type)) {
+            return new JavaObject(new byte[0], Array.newInstance(byte.class, 0).getClass());
+        } else if ("System.Char[]".equals(type)) {
+            return new JavaObject(new char[0], Array.newInstance(char.class, 0).getClass());
+        } else if ("System.Double[]".equals(type)) {
+            return new JavaObject(new double[0], Array.newInstance(double.class, 0).getClass());
+        } else if ("System.Single[]".equals(type)) {
+            return new JavaObject(new float[0], Array.newInstance(float.class, 0).getClass());
+        } else if ("System.Int64[]".equals(type)) {
+            return new JavaObject(new long[0], Array.newInstance(long.class, 0).getClass());
+        } else if ("System.String[]".equals(type)) {
+            return new JavaObject(new String[0], Array.newInstance(String.class, 0).getClass());
+        } else if ("System.Int16[]".equals(type)) {
+            return new JavaObject(new short[0], Array.newInstance(short.class, 0).getClass());
+        }
+        return new JavaObject(new Object[0], Array.newInstance(Object.class, 0).getClass());
+    }
+
     public JSONObject SerializeToDotNet(ObjectInstance obj) {
         return new JSONObject();
     }

Activities/Java/UiPath.Java/Service/JavaObjectInstance.cs

@@ -35,6 +35,9 @@ public object Value
         [DataMember(Name = "runtime_type", EmitDefaultValue = false)]
         public string RunTimeType { get; set; }
 
+        [DataMember(Name = "runtime_arrayType", EmitDefaultValue = false)]
+        public string RunTimeArrayType { get; set; }
+
         [DataMember(Name = "reference_id", EmitDefaultValue = false)]
         public string ReferenceId { get; set; }
 
@@ -68,6 +71,7 @@ private void SetValue(object value)
                     }
                 }).ToList();
                 RunTimeType = "Array";
+                RunTimeArrayType = value?.GetType()?.ToString();
             }
             else
             {