Refactor - create a ValidationResult Builder class

In anticipation of the Validation Result output adopting the common
event payload, add an interface to provide a greater level of
abstraction between the current implementation and the classes that
create validation results.

Change-Id: Ie81228dff19a124011e77097768b44be5a3844b6
Issue-ID: AAI-2057
Signed-off-by: mark.j.leonard <mark.j.leonard@gmail.com>

7 files changed, 369 insertions, 232 deletions

diff --git a/src/main/java/org/onap/aai/validation/controller/ValidationController.java b/src/main/java/org/onap/aai/validation/controller/ValidationController.java
index 15e35b1..bd7c850 100644
--- a/src/main/java/org/onap/aai/validation/controller/ValidationController.java
+++ b/src/main/java/org/onap/aai/validation/controller/ValidationController.java
@@ -1,12 +1,12 @@
-/*
+/**
  * ============LICENSE_START===================================================
- * Copyright (c) 2018 Amdocs
+ * Copyright (c) 2018-2019 European Software Marketing Ltd.
  * ============================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
- *        http://www.apache.org/licenses/LICENSE-2.0
+ *       http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
@@ -42,6 +42,7 @@ import org.onap.aai.validation.publisher.MessagePublisher;
 import org.onap.aai.validation.reader.EventReader;
 import org.onap.aai.validation.reader.data.Entity;
 import org.onap.aai.validation.result.ValidationResult;
+import org.onap.aai.validation.result.ValidationResultBuilder;
 import org.onap.aai.validation.result.Violation;
 import org.onap.aai.validation.util.JsonUtil;
 
@@ -105,7 +106,7 @@ public class ValidationController {
                 Entity entity = eventReader.getEntity(event);
                 if (!entity.getIds().isEmpty() && eventReader.getEntityType(event).isPresent()
                         && entity.getResourceVersion().isPresent()) {
-                    ValidationResult validationResult = new ValidationResult(entity);
+                    ValidationResult validationResult = new ValidationResultBuilder(eventReader, event).build();
                     // @formatter:off
 					validationResult.addViolation(new Violation.Builder(entity)
 						.category(VALIDATION_ERROR_CATEGORY)
diff --git a/src/main/java/org/onap/aai/validation/modeldriven/validator/ModelDrivenValidator.java b/src/main/java/org/onap/aai/validation/modeldriven/validator/ModelDrivenValidator.java
index 1b8ab00..ef27f40 100644
--- a/src/main/java/org/onap/aai/validation/modeldriven/validator/ModelDrivenValidator.java
+++ b/src/main/java/org/onap/aai/validation/modeldriven/validator/ModelDrivenValidator.java
@@ -1,12 +1,12 @@
-/*
+/**
  * ============LICENSE_START===================================================
- * Copyright (c) 2018 Amdocs
+ * Copyright (c) 2018-2019 European Software Marketing Ltd.
  * ============================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
- *        http://www.apache.org/licenses/LICENSE-2.0
+ *       http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
@@ -36,14 +36,15 @@ import org.onap.aai.validation.exception.ValidationServiceException;
 import org.onap.aai.validation.modeldriven.ModelCacheManager;
 import org.onap.aai.validation.modeldriven.ModelId;
 import org.onap.aai.validation.modeldriven.configuration.mapping.ModelInstanceMapper;
-import org.onap.aai.validation.modeldriven.configuration.mapping.ModelInstanceMappingReader;
 import org.onap.aai.validation.modeldriven.configuration.mapping.ModelInstanceMapper.MappingType;
+import org.onap.aai.validation.modeldriven.configuration.mapping.ModelInstanceMappingReader;
 import org.onap.aai.validation.reader.EntityReader;
 import org.onap.aai.validation.reader.EventReader;
 import org.onap.aai.validation.reader.InstanceEntityReader;
 import org.onap.aai.validation.reader.data.Entity;
 import org.onap.aai.validation.reader.data.EntityId;
 import org.onap.aai.validation.result.ValidationResult;
+import org.onap.aai.validation.result.ValidationResultBuilder;
 import org.onap.aai.validation.result.Violation;
 import org.onap.aai.validation.result.Violation.Builder;
 import org.onap.aai.validation.result.Violation.ViolationType;
@@ -148,7 +149,7 @@ public class ModelDrivenValidator implements Validator {
 			}
 		}
 
-		ValidationResult validationResult = new ValidationResult(instanceEntity);
+		ValidationResult validationResult = new ValidationResultBuilder(instanceEntity).build();
 
 		// This is a shortcut to passing the parent model name all the way down.
 		populateViolationModelNames(violations, instanceEntity);
diff --git a/src/main/java/org/onap/aai/validation/result/ValidationResult.java b/src/main/java/org/onap/aai/validation/result/ValidationResult.java
index b632a0f..9526c03 100644
--- a/src/main/java/org/onap/aai/validation/result/ValidationResult.java
+++ b/src/main/java/org/onap/aai/validation/result/ValidationResult.java
@@ -1,12 +1,12 @@
-/*
+/**
  * ============LICENSE_START===================================================
- * Copyright (c) 2018 Amdocs
+ * Copyright (c) 2018-2019 European Software Marketing Ltd.
  * ============================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
- *        http://www.apache.org/licenses/LICENSE-2.0
+ *       http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
@@ -18,227 +18,47 @@
 package org.onap.aai.validation.result;
 
 import com.google.gson.JsonElement;
-import com.google.gson.JsonObject;
-import com.google.gson.JsonParser;
-import com.google.gson.annotations.Expose;
-import java.time.Instant;
-import java.time.ZoneOffset;
-import java.time.format.DateTimeFormatter;
-import java.util.ArrayList;
 import java.util.List;
-import java.util.Objects;
-import java.util.UUID;
-import org.apache.commons.lang3.builder.EqualsBuilder;
-import org.onap.aai.validation.exception.ValidationServiceException;
-import org.onap.aai.validation.reader.data.Entity;
-import org.onap.aai.validation.reader.data.EntityId;
-import org.onap.aai.validation.util.JsonUtil;
-
-/**
- * The result of an instance validation. This can include zero or more {@link Violation} objects.
- */
-public class ValidationResult {
-
-    @Expose
-    private String validationId;
 
-    @Expose
-    private String validationTimestamp;
+public interface ValidationResult {
 
-    @Expose
-    private JsonElement entityId;
+    List<Violation> getViolations();
 
-    @Expose
-    private String entityType;
+    JsonElement getEntityId();
 
-    @Expose
-    private String entityLink;
+    String getEntityLink();
 
-    @Expose
-    private String resourceVersion;
-    
-    @Expose
-    private JsonElement entity;
+    String getEntityType();
 
-
-	@Expose
-    private List<Violation> violations = new ArrayList<>();
-
-    /**
-     * Create the validation payload initialised with an event identifier and a timestamp.
-     *
-     * @param entity
-     * @throws ValidationServiceException
-     */
-    public ValidationResult(Entity entity) throws ValidationServiceException {
-        this.validationId = UUID.randomUUID().toString();
-        this.validationTimestamp =
-                DateTimeFormatter.ofPattern("yyyyMMdd'T'HHmmssX").withZone(ZoneOffset.UTC).format(Instant.now());
-        this.entityId = new JsonObject();
-        for (EntityId id : entity.getIds()) {
-            this.entityId.getAsJsonObject().addProperty(id.getPrimaryKey(), id.getValue());
-        }
-        this.entityType = entity.getType();
-        this.entityLink = entity.getEntityLink();
-        this.resourceVersion = entity.getResourceVersion().orElse(null);   
-        this.entity = entity.getJson()!=null ?new JsonParser().parse(entity.getJson()): new JsonObject();
-    }    
- 
+    String getResourceVersion();
 
     /**
-     * Add a validation violation.
+     * Add a single validation violation.
      *
      * @param violation a single {@link Violation} to add to the validation result
      */
-    public void addViolation(Violation violation) {
-        this.violations.add(violation);
-    }
+    void addViolation(Violation violation);
 
     /**
      * Add a list of validation violations.
      *
      * @param violations a List of {@link Violation} objects to add to the validation result
      */
-    public void addViolations(List<Violation> violations) {
-        this.violations.addAll(violations);
-    }
-
-    public String getValidationId() {
-        return validationId;
-    }
-
-    public void setValidationId(String eventId) {
-        this.validationId = eventId;
-    }
-
-    public String getValidationTimestamp() {
-        return validationTimestamp;
-    }
-
-    public void setValidationTimestamp(String timestamp) {
-        this.validationTimestamp = timestamp;
-    }
-
-    public JsonElement getEntityId() {
-        return entityId;
-    }
-
-    public void setEntityId(JsonElement entityId) {
-        this.entityId = entityId;
-    }
-
-    public String getEntityType() {
-        return entityType;
-    }
-
-    public void setEntityType(String entityType) {
-        this.entityType = entityType;
-    }
-
-    public String getEntityLink() {
-        return entityLink;
-    }
-
-    public void setEntityLink(String uri) {
-        this.entityLink = uri;
-    }
-
-    public String getResourceVersion() {
-        return resourceVersion;
-    }
-
-    public void setResourceVersion(String resourceVersion) {
-        this.resourceVersion = resourceVersion;
-    }
-
-    public JsonElement getEntity() {
-		return entity;
-	}
-
-	public void setEntity(JsonElement entity) {
-		this.entity = entity;
-	}
-	
-    public List<Violation> getViolations() {
-        return violations;
-    }
-
-    public void setViolations(List<Violation> violations) {
-        this.violations = violations;
-    }
-
-    @Override
-    public int hashCode() {
-        return Objects.hash(this.entityId, this.entityLink, this.entityType, this.resourceVersion, this.validationId,
-                this.validationTimestamp, this.violations, this.entity);
-    }
-
-    /*
-     * validationId is checked first, as this is meant to be unique
-     *
-     * @see java.lang.Object#equals(java.lang.Object)
-     */
-    @Override
-    public boolean equals(Object obj) {
-        if (!(obj instanceof ValidationResult)) {
-            return false;
-        } else if (obj == this) {
-            return true;
-        }
-        ValidationResult rhs = (ValidationResult) obj;
-     // @formatter:off
-     return new EqualsBuilder()
-                  .append(entityId, rhs.entityId)
-                  .append(entityLink, rhs.entityLink)
-                  .append(entityType, rhs.entityType)
-                  .append(resourceVersion, rhs.resourceVersion)
-                  .append(validationId, rhs.validationId)
-                  .append(validationTimestamp, rhs.validationTimestamp)
-                  .append(violations, rhs.violations)
-                  .append(entity, rhs.entity)
-                  .isEquals();
-     // @formatter:on
-    }
-
-    @Override
-    public String toString() {
-        return JsonUtil.toJson(this);
-    }
+    void addViolations(List<Violation> violations);
 
     /**
      * Create a JSON representation of the object, with each violation's validationRule omitted when it has a null value
      *
      * @return this object formatted as a JSON string ready for publishing
      */
-    public String toJson() {
-        return toString();
-    }
+    String toJson();
 
-    /**
-     * Create a new object from the JSON representation
-     *
-     * @param json representation of the Validation Result
-     * @return a ValidationResult object
-     */
-    public static ValidationResult fromJson(String json) {
-        ValidationResult validationResult = JsonUtil.toAnnotatedClassfromJson(json, ValidationResult.class);
-        if (validationResult != null) {
-            validationResult.initialiseValues();
-        }
-        return validationResult;
-    }
+    String getValidationId();
+
+    String getValidationTimestamp();
+
+    void setEntityId(JsonElement entityId);
+
+    void setEntityType(String entityType);
 
-    /**
-     * Ensure that any unset fields are properly initialised. This is particularly useful when the object has been
-     * deserialised from a JSON string, as any missing/undefined values will not be read by the deserialiser and thus
-     * the corresponding fields will not be set.
-     */
-    private void initialiseValues() {
-        List<Violation> violationList = getViolations();
-        if (violationList != null) {
-            for (Violation violation : violationList) {
-                violation.initialiseValues();
-            }
-        }
-    }
 }
diff --git a/src/main/java/org/onap/aai/validation/result/ValidationResultBuilder.java b/src/main/java/org/onap/aai/validation/result/ValidationResultBuilder.java
new file mode 100644
index 0000000..743e08d
--- /dev/null
+++ b/src/main/java/org/onap/aai/validation/result/ValidationResultBuilder.java
@@ -0,0 +1,55 @@
+/**
+ * ============LICENSE_START===================================================
+ * Copyright (c) 2018-2019 European Software Marketing Ltd.
+ * ============================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=====================================================
+ */
+package org.onap.aai.validation.result;
+
+import org.onap.aai.validation.exception.ValidationServiceException;
+import org.onap.aai.validation.reader.EventReader;
+import org.onap.aai.validation.reader.data.Entity;
+
+public class ValidationResultBuilder {
+
+    private final EventReader eventReader;
+    private final String event;
+    private Entity entity;
+
+    public ValidationResultBuilder(EventReader eventReader, String event) {
+        this.eventReader = eventReader;
+        this.event = event;
+    }
+
+    public ValidationResultBuilder(Entity entity) {
+        this.eventReader = null;
+        this.event = null;
+        this.entity = entity;
+    }
+
+    public static ValidationResult fromJson(String json) {
+        return ValidationResultImpl.fromJson(json);
+    }
+
+    public ValidationResult build() throws ValidationServiceException {
+        return new ValidationResultImpl(getEntity());
+    }
+
+    private Entity getEntity() throws ValidationServiceException {
+        if (entity == null) {
+            entity = eventReader.getEntity(event);
+        }
+        return entity;
+    }
+}
diff --git a/src/main/java/org/onap/aai/validation/result/ValidationResultImpl.java b/src/main/java/org/onap/aai/validation/result/ValidationResultImpl.java
new file mode 100644
index 0000000..376a41c
--- /dev/null
+++ b/src/main/java/org/onap/aai/validation/result/ValidationResultImpl.java
@@ -0,0 +1,255 @@
+/**
+ * ============LICENSE_START===================================================
+ * Copyright (c) 2018-2019 European Software Marketing Ltd.
+ * ============================================================================
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *       http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ * ============LICENSE_END=====================================================
+ */
+package org.onap.aai.validation.result;
+
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
+import com.google.gson.annotations.Expose;
+import java.time.Instant;
+import java.time.ZoneOffset;
+import java.time.format.DateTimeFormatter;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Objects;
+import java.util.UUID;
+import org.apache.commons.lang3.builder.EqualsBuilder;
+import org.onap.aai.validation.exception.ValidationServiceException;
+import org.onap.aai.validation.reader.data.Entity;
+import org.onap.aai.validation.reader.data.EntityId;
+import org.onap.aai.validation.util.JsonUtil;
+
+/**
+ * The result of an instance validation. This can include zero or more {@link Violation} objects.
+ */
+public class ValidationResultImpl implements ValidationResult {
+
+    @Expose
+    private String validationId;
+
+    @Expose
+    private String validationTimestamp;
+
+    @Expose
+    private JsonElement entityId;
+
+    @Expose
+    private String entityType;
+
+    @Expose
+    private String entityLink;
+
+    @Expose
+    private String resourceVersion;
+
+    @Expose
+    private JsonElement entity;
+
+
+    @Expose
+    private List<Violation> violations = new ArrayList<>();
+
+    /**
+     * Create the validation payload initialised with an event identifier and a timestamp.
+     *
+     * @param entity
+     * @throws ValidationServiceException
+     */
+    public ValidationResultImpl(Entity entity) throws ValidationServiceException {
+        this.validationId = UUID.randomUUID().toString();
+        this.validationTimestamp =
+                DateTimeFormatter.ofPattern("yyyyMMdd'T'HHmmssX").withZone(ZoneOffset.UTC).format(Instant.now());
+        this.entityId = new JsonObject();
+        for (EntityId id : entity.getIds()) {
+            this.entityId.getAsJsonObject().addProperty(id.getPrimaryKey(), id.getValue());
+        }
+        this.entityType = entity.getType();
+        this.entityLink = entity.getEntityLink();
+        this.resourceVersion = entity.getResourceVersion().orElse(null);
+        this.entity = entity.getJson() != null ? new JsonParser().parse(entity.getJson()) : new JsonObject();
+    }
+
+    /**
+     * Add a validation violation.
+     *
+     * @param violation a single {@link Violation} to add to the validation result
+     */
+    @Override
+    public void addViolation(Violation violation) {
+        this.violations.add(violation);
+    }
+
+    /**
+     * Add a list of validation violations.
+     *
+     * @param violations a List of {@link Violation} objects to add to the validation result
+     */
+    @Override
+    public void addViolations(List<Violation> violations) {
+        this.violations.addAll(violations);
+    }
+
+    @Override
+    public String getValidationId() {
+        return validationId;
+    }
+
+    public void setValidationId(String eventId) {
+        this.validationId = eventId;
+    }
+
+    @Override
+    public String getValidationTimestamp() {
+        return validationTimestamp;
+    }
+
+    public void setValidationTimestamp(String timestamp) {
+        this.validationTimestamp = timestamp;
+    }
+
+    @Override
+    public JsonElement getEntityId() {
+        return entityId;
+    }
+
+    @Override
+    public void setEntityId(JsonElement entityId) {
+        this.entityId = entityId;
+    }
+
+    @Override
+    public String getEntityType() {
+        return entityType;
+    }
+
+    @Override
+    public void setEntityType(String entityType) {
+        this.entityType = entityType;
+    }
+
+    @Override
+    public String getEntityLink() {
+        return entityLink;
+    }
+
+    public void setEntityLink(String uri) {
+        this.entityLink = uri;
+    }
+
+    @Override
+    public String getResourceVersion() {
+        return resourceVersion;
+    }
+
+    public void setResourceVersion(String resourceVersion) {
+        this.resourceVersion = resourceVersion;
+    }
+
+    public JsonElement getEntity() {
+        return entity;
+    }
+
+    public void setEntity(JsonElement entity) {
+        this.entity = entity;
+    }
+
+    @Override
+    public List<Violation> getViolations() {
+        return violations;
+    }
+
+    public void setViolations(List<Violation> violations) {
+        this.violations = violations;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(this.entityId, this.entityLink, this.entityType, this.resourceVersion, this.validationId,
+                this.validationTimestamp, this.violations, this.entity);
+    }
+
+    /*
+     * validationId is checked first, as this is meant to be unique
+     *
+     * @see java.lang.Object#equals(java.lang.Object)
+     */
+    @Override
+    public boolean equals(Object obj) {
+        if (!(obj instanceof ValidationResultImpl)) {
+            return false;
+        } else if (obj == this) {
+            return true;
+        }
+        ValidationResultImpl rhs = (ValidationResultImpl) obj;
+     // @formatter:off
+     return new EqualsBuilder()
+                  .append(entityId, rhs.entityId)
+                  .append(entityLink, rhs.entityLink)
+                  .append(entityType, rhs.entityType)
+                  .append(resourceVersion, rhs.resourceVersion)
+                  .append(validationId, rhs.validationId)
+                  .append(validationTimestamp, rhs.validationTimestamp)
+                  .append(violations, rhs.violations)
+                  .append(entity, rhs.entity)
+                  .isEquals();
+     // @formatter:on
+    }
+
+    @Override
+    public String toString() {
+        return JsonUtil.toJson(this);
+    }
+
+    /**
+     * Create a JSON representation of the object, with each violation's validationRule omitted when it has a null value
+     *
+     * @return this object formatted as a JSON string ready for publishing
+     */
+    @Override
+    public String toJson() {
+        return toString();
+    }
+
+    /**
+     * Create a new object from the JSON representation
+     *
+     * @param json representation of the Validation Result
+     * @return a ValidationResult object
+     */
+    public static ValidationResultImpl fromJson(String json) {
+        ValidationResultImpl validationResult = JsonUtil.toAnnotatedClassfromJson(json, ValidationResultImpl.class);
+        if (validationResult != null) {
+            validationResult.initialiseValues();
+        }
+        return validationResult;
+    }
+
+    /**
+     * Ensure that any unset fields are properly initialised. This is particularly useful when the object has been
+     * deserialised from a JSON string, as any missing/undefined values will not be read by the deserialiser and thus
+     * the corresponding fields will not be set.
+     */
+    private void initialiseValues() {
+        List<Violation> violationList = getViolations();
+        if (violationList != null) {
+            for (Violation violation : violationList) {
+                violation.initialiseValues();
+            }
+        }
+    }
+}
diff --git a/src/main/java/org/onap/aai/validation/ruledriven/RuleDrivenValidator.java b/src/main/java/org/onap/aai/validation/ruledriven/RuleDrivenValidator.java
index 49b251e..cee29f7 100644
--- a/src/main/java/org/onap/aai/validation/ruledriven/RuleDrivenValidator.java
+++ b/src/main/java/org/onap/aai/validation/ruledriven/RuleDrivenValidator.java
@@ -1,6 +1,6 @@
 /*
  * ============LICENSE_START===================================================
- * Copyright (c) 2018 Amdocs
+ * Copyright (c) 2018-2019 European Software Marketing Ltd.
  * ============================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -33,6 +33,7 @@ import java.util.Map;
 import java.util.Optional;
 import java.util.function.Consumer;
 import java.util.stream.Stream;
+import org.apache.commons.lang.StringUtils;
 import org.onap.aai.validation.Validator;
 import org.onap.aai.validation.config.RuleIndexingConfig;
 import org.onap.aai.validation.exception.ValidationServiceError;
@@ -44,6 +45,7 @@ import org.onap.aai.validation.reader.OxmReader;
 import org.onap.aai.validation.reader.data.AttributeValues;
 import org.onap.aai.validation.reader.data.Entity;
 import org.onap.aai.validation.result.ValidationResult;
+import org.onap.aai.validation.result.ValidationResultBuilder;
 import org.onap.aai.validation.result.Violation;
 import org.onap.aai.validation.result.Violation.ViolationType;
 import org.onap.aai.validation.ruledriven.configuration.EntitySection;
@@ -136,9 +138,9 @@ public class RuleDrivenValidator implements Validator {
      *
      * @param entityType
      * @param eventType
-     * @return the rules defined for this entityType
+     * @return the Optional rules defined for this entityType
      */
-    public List<Rule> getRulesForEntity(String entityType, String eventType) {
+    public Optional<List<Rule>> getRulesForEntity(String entityType, String eventType) {
         return ruleManagers.get(eventType.toLowerCase(Locale.getDefault())).getRulesForEntity(entityType);
     }
 
@@ -152,11 +154,10 @@ public class RuleDrivenValidator implements Validator {
 
         Entity entity = getEventReader().getEntity(event);
         Optional<String> eventType = eventReader.getEventType(event);
-        List<Rule> rules = getRulesToApply(entity, eventType).orElse(null);
-        if (rules == null) {
-            throw new ValidationServiceException(ValidationServiceError.RULES_NOT_DEFINED, eventType.orElse(null));
-        }
-        ValidationResult validationResult = new ValidationResult(entity);
+        List<Rule> rules = getRulesToApply(entity, eventType).orElseThrow(
+                () -> new ValidationServiceException(ValidationServiceError.RULES_NOT_DEFINED, eventType.orElse(null)));
+
+        ValidationResult validationResult = new ValidationResultBuilder(eventReader, event).build();
         Violation.Builder builder = new Violation.Builder(entity);
 
         for (Rule rule : rules) {
@@ -207,7 +208,7 @@ public class RuleDrivenValidator implements Validator {
                         && ruleIndexingConfig.get().getIndexedEvents().contains(eventType.get())) {
                     rules = getRulesByIndex(entity, eventType.get(), ruleManager.get());
                 } else {
-                    rules = Optional.of(ruleManager.get().getRulesForEntity(entity.getType()));
+                    rules = ruleManager.get().getRulesForEntity(entity.getType());
                 }
             }
         }
@@ -217,18 +218,21 @@ public class RuleDrivenValidator implements Validator {
     private Optional<List<Rule>> getRulesByIndex(Entity entity, String eventType, RuleManager ruleManager) {
         String rulesKey = generateKey(entity, eventType);
         applicationLogger.debug(String.format("Retrieving indexed rules for key '%s'", rulesKey));
-        Optional<List<Rule>> rules = Optional.of(ruleManager.getRulesForEntity(rulesKey));
-        if (rules.get().isEmpty() && ruleIndexingConfig.isPresent()) {
-            if (ruleIndexingConfig.get().getDefaultIndexKey() == null
-                    || ruleIndexingConfig.get().getDefaultIndexKey().isEmpty()) {
+
+        final Optional<List<Rule>> entityRules = ruleManager.getRulesForEntity(rulesKey);
+        final boolean rulesDefined = entityRules.filter(l -> !l.isEmpty()).isPresent();
+
+        if (!rulesDefined && ruleIndexingConfig.isPresent()) {
+            final String defaultIndexKey = ruleIndexingConfig.get().getDefaultIndexKey();
+            if (StringUtils.isEmpty(defaultIndexKey)) {
+                return ruleManager.getRulesForEntity(RuleManager.generateKey(new String[] { defaultIndexKey }));
+            } else {
                 applicationLogger.debug("Default index value not configured, unable to get rules");
                 applicationLogger.error(ApplicationMsgs.CANNOT_VALIDATE_ERROR, eventType);
-                return rules;
             }
-            String defaultKey = RuleManager.generateKey(new String[] { ruleIndexingConfig.get().getDefaultIndexKey() });
-            rules = Optional.of(ruleManager.getRulesForEntity(defaultKey));
         }
-        return rules;
+
+        return entityRules;
     }
 
     private String generateKey(Entity entity, String eventType) {
diff --git a/src/main/java/org/onap/aai/validation/ruledriven/RuleManager.java b/src/main/java/org/onap/aai/validation/ruledriven/RuleManager.java
index c21ce24..380c99a 100644
--- a/src/main/java/org/onap/aai/validation/ruledriven/RuleManager.java
+++ b/src/main/java/org/onap/aai/validation/ruledriven/RuleManager.java
@@ -1,6 +1,6 @@
 /*
  * ============LICENSE_START===================================================
- * Copyright (c) 2018 Amdocs
+ * Copyright (c) 2018-2019 European Software Marketing Ltd.
  * ============================================================================
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -24,6 +24,7 @@ import java.util.Iterator;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.SortedSet;
 import java.util.TreeSet;
 import org.onap.aai.validation.ruledriven.configuration.EntitySection;
@@ -45,7 +46,8 @@ public class RuleManager {
     /**
      * Create the rules for each type of entity based on the supplied configuration
      *
-     * @param entities configuration (all entities)
+     * @param entities
+     *        configuration (all entities)
      * @throws InstantiationException
      * @throws IllegalAccessException
      * @throws GroovyConfigurationException
@@ -69,11 +71,10 @@ public class RuleManager {
 
     /**
      * @param entityType
-     * @return the rules configured for this entity type
+     * @return the Optional rules configured for this entity type
      */
-    public List<Rule> getRulesForEntity(String entityType) {
-        List<Rule> rules = rulesMap.get(entityType);
-        return rules == null ? Collections.emptyList() : rules;
+    public Optional<List<Rule>> getRulesForEntity(String entityType) {
+        return Optional.ofNullable(rulesMap.get(entityType));
     }
 
     public static String generateKey(String[] indices) {