[incubator-kie-issues#875] DMN - Do not create an exception when prop…

…erty is not defined. (apache#5672)

kie-dmn/kie-dmn-feel/src/main/java/org/kie/dmn/feel/util/EvalHelper.java

@@ -287,6 +287,11 @@ public static String unescapeString(String text) {
 
     public static class PropertyValueResult implements FEELPropertyAccessible.AbstractPropertyValueResult {
 
+        // This exception is used to signal an undefined property for notDefined(). This method may be many times when
+        // evaluating a decision, so a single instance is being cached to avoid the cost of creating the stack trace
+        // each time.
+        private static final Exception undefinedPropertyException = new UnsupportedOperationException("Property was not defined.");
+
         private final boolean defined;
         private final Either<Exception, Object> valueResult;
 
@@ -296,7 +301,7 @@ private PropertyValueResult(boolean isDefined, Either<Exception, Object> value)
         }
 
         public static PropertyValueResult notDefined() {
-            return new PropertyValueResult(false, Either.ofLeft(new UnsupportedOperationException("Property was not defined.")));
+            return new PropertyValueResult(false, Either.ofLeft(undefinedPropertyException));
         }
 
         public static PropertyValueResult of(Either<Exception, Object> valueResult) {
@@ -782,4 +787,4 @@ public String toString() {
                     '}';
         }
     }
-}
+}