Merge "Improve validation, add hierarchical validation"

10 files changed, 811 insertions, 84 deletions

diff --git a/common-parameters/src/main/java/org/onap/policy/common/parameters/GroupMapValidationResult.java b/common-parameters/src/main/java/org/onap/policy/common/parameters/GroupMapValidationResult.java
new file mode 100644
index 00000000..09cdc1de
--- /dev/null
+++ b/common-parameters/src/main/java/org/onap/policy/common/parameters/GroupMapValidationResult.java
@@ -0,0 +1,163 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * 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.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.parameters;
+
+import java.lang.reflect.Field;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Map.Entry;
+
+/**
+ * This class holds the result of the validation of a map of parameter groups.
+ */
+public class GroupMapValidationResult implements ValidationResult {
+    // The name of the parameter group map
+    final String mapParameterName;
+    
+    // Validation status for the entire parameter class
+    private ValidationStatus status = ValidationStatus.CLEAN;
+    private String message = ParameterConstants.PARAMETER_GROUP_MAP_HAS_STATUS_MESSAGE + status.toString();
+
+    // Validation results for each parameter in the group
+    private final Map<String, ValidationResult> validationResultMap = new LinkedHashMap<>();
+
+    /**
+     * Constructor, create the group map validation result.
+     *
+     * @param field the map parameter field
+     * @param mapObject the value of the map parameter field
+     */
+    protected GroupMapValidationResult(final Field field, final Object mapObject) {
+        this.mapParameterName = field.getName();
+
+        // Cast the map object to a map of parameter groups keyed by string, we can't type check maps
+        // due to restrictions on generics so we have to check each entry key is a string and each entry
+        // value is a parameter group
+        @SuppressWarnings("unchecked")
+        Map<String, ParameterGroup> parameterGroupMap = (Map<String, ParameterGroup>) mapObject;
+
+        // Add a validation result per map entry
+        for (Entry<String, ParameterGroup> parameterGroupMapEntry : parameterGroupMap.entrySet()) {
+            // Create a validation status entry for the map
+            validationResultMap.put(parameterGroupMapEntry.getKey(),
+                            new GroupValidationResult(parameterGroupMapEntry.getValue()));
+        }
+    }
+
+    /**
+     * Gets the name of the parameter being validated.
+     *
+     * @return the name
+     */
+    @Override
+    public String getName() {
+        return mapParameterName;
+    }
+
+    /**
+     * Gets the status of validation.
+     *
+     * @return the status
+     */
+    @Override
+    public ValidationStatus getStatus() {
+        return status;
+    }
+
+    /**
+     * Set the validation result on on a parameter group.
+     * 
+     * @param status The validation status the field is receiving
+     * @param message The validation message explaining the validation status
+     */
+    @Override
+    public void setResult(ValidationStatus status, String message) {
+        setResult(status);
+        this.message = message;
+    }
+
+    /**
+     * Set the validation result on on a parameter group.
+     * 
+     * @param status The validation status the field is receiving
+     */
+    public void setResult(final ValidationStatus status) {
+        // We record the most serious validation status, assuming the status enum ordinals
+        // increase in order of severity
+        if (this.status.ordinal() < status.ordinal()) {
+            this.status = status;
+            this.message = ParameterConstants.PARAMETER_GROUP_HAS_STATUS_MESSAGE + status.toString();
+        }
+    }
+
+    /**
+     * Set the validation result on a parameter map entry.
+     * 
+     * @param entryName The name of the parameter map entry
+     * @param mapEntryValidationResult The validation result for the entry
+     */
+    public void setResult(String entryName, ValidationResult mapEntryValidationResult) {
+        ValidationResult validationResult = validationResultMap.get(entryName);
+        if (validationResult == null) {
+            throw new ParameterRuntimeException("no entry with name \"" + entryName + "\" exists");
+        }
+
+        // Set the status of the parameter group and replace the field result
+        validationResultMap.put(entryName, mapEntryValidationResult);
+        this.setResult(status);
+    }
+
+    /**
+     * Gets the validation result.
+     *
+     * @param initialIndentation the indentation to use on the main result output
+     * @param subIndentation the indentation to use on sub parts of the result output
+     * @param showClean output information on clean fields
+     * @return the result
+     */
+    @Override
+    public String getResult(final String initialIndentation, final String subIndentation, final boolean showClean) {
+        if (status == ValidationStatus.CLEAN && !showClean) {
+            return null;
+        }
+
+        StringBuilder validationResultBuilder = new StringBuilder();
+
+        validationResultBuilder.append(initialIndentation);
+        validationResultBuilder.append("parameter group map \"");
+        validationResultBuilder.append(mapParameterName);
+        validationResultBuilder.append("\" ");
+        validationResultBuilder.append(status);
+        validationResultBuilder.append(", ");
+        validationResultBuilder.append(message);
+        validationResultBuilder.append('\n');
+
+        for (ValidationResult fieldResult : validationResultMap.values()) {
+            String fieldResultMessage = fieldResult.getResult(initialIndentation + subIndentation, subIndentation,
+                            showClean);
+            if (fieldResultMessage != null) {
+                validationResultBuilder.append(fieldResultMessage);
+            }
+        }
+
+        return validationResultBuilder.toString();
+    }
+}
\ No newline at end of file
diff --git a/common-parameters/src/main/java/org/onap/policy/common/parameters/GroupValidationResult.java b/common-parameters/src/main/java/org/onap/policy/common/parameters/GroupValidationResult.java
new file mode 100644
index 00000000..91c3d145
--- /dev/null
+++ b/common-parameters/src/main/java/org/onap/policy/common/parameters/GroupValidationResult.java
@@ -0,0 +1,324 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * 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.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.parameters;
+
+import java.lang.reflect.Field;
+import java.util.Collection;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Map.Entry;
+
+/**
+ * This class holds the result of the validation of a parameter group.
+ */
+public class GroupValidationResult implements ValidationResult {
+    // The parameter group which the validation result applies
+    private final ParameterGroup parameterGroup;
+
+    // Validation status for the entire parameter class
+    private ValidationStatus status = ValidationStatus.CLEAN;
+    private String message = ParameterConstants.PARAMETER_GROUP_HAS_STATUS_MESSAGE + status.toString();
+
+    // Validation results for each parameter in the group
+    private final Map<String, ValidationResult> validationResultMap = new LinkedHashMap<>();
+
+    /**
+     * Constructor, create the field validation result with default arguments.
+     *
+     * @param parameterGroup the parameter group being validated
+     */
+    public GroupValidationResult(final ParameterGroup parameterGroup) {
+        this.parameterGroup = parameterGroup;
+
+        // Add a validation result per field
+        for (Field field : parameterGroup.getClass().getDeclaredFields()) {
+            // Exclude system fields
+            if (field.getName().startsWith("$") || field.getName().startsWith("_")) {
+                continue;
+            }
+
+            // Make the field accessible
+            boolean savedAccessibilityValue = field.isAccessible();
+            field.setAccessible(true);
+
+            try {
+                // Set the validation result
+                validationResultMap.put(field.getName(), getValidationResult(field, parameterGroup));
+            } catch (IllegalArgumentException | IllegalAccessException e) {
+                throw new ParameterRuntimeException("could not get value of parameter \"" + field.getName() + "\"", e);
+            } finally {
+                field.setAccessible(savedAccessibilityValue);
+            }
+        }
+    }
+
+    /**
+     * Construct a validation result for a field
+     * 
+     * @param field The parameter field
+     * @param ParameterGroup The parameter group containing the field
+     * @return the validation result
+     * @throws IllegalAccessException on accessing private fields
+     */
+    private ValidationResult getValidationResult(final Field field, final ParameterGroup parameterGroup)
+                    throws IllegalAccessException {
+        final String fieldName = field.getName();
+        final Class<?> fieldType = field.getType();
+        final Object fieldObject = field.get(parameterGroup);
+
+        // Nested parameter groups are allowed
+        if (ParameterGroup.class.isAssignableFrom(fieldType)) {
+            return new GroupValidationResult((ParameterGroup) field.get(parameterGroup));
+        }
+        
+        // Nested maps of parameter groups are allowed
+        if (Map.class.isAssignableFrom(field.getType())) {
+            checkMapIsParameterGroupMap(fieldName, fieldObject);
+            return new GroupMapValidationResult(field, fieldObject);
+        }
+        
+        // Collections of parameter groups are not allowed
+        if (Collection.class.isAssignableFrom(field.getType())) {
+            checkCollection4ParameterGroups(fieldName, fieldObject);
+            return new ParameterValidationResult(field, fieldObject);
+        }
+
+        // It's a regular parameter
+        return new ParameterValidationResult(field, fieldObject);
+    }
+
+    /**
+     * Check if this field is a map of parameter groups indexed by string keys.
+     * 
+     * @param fieldName the name of the collection field.
+     * @param mapObject the map object to check
+     */
+    private void checkMapIsParameterGroupMap(String fieldName, Object mapObject) {
+        if (mapObject == null) {
+            throw new ParameterRuntimeException("map parameter \"" + fieldName + "\" is null");
+        }
+        
+        Map<?, ?> incomingMap = (Map<?, ?>) mapObject;
+
+        for (Entry<?, ?> mapEntry : incomingMap.entrySet()) {
+            // Check the key is a string
+            if (!String.class.isAssignableFrom(mapEntry.getKey().getClass())) {
+                throw new ParameterRuntimeException("map entry is not a parameter group keyed by a string, key \""
+                                + mapEntry.getKey() + "\" in map \"" + fieldName + "\" is not a string");
+            }
+
+            // Check the value is a parameter group
+            if (!ParameterGroup.class.isAssignableFrom(mapEntry.getValue().getClass())) {
+                throw new ParameterRuntimeException("map entry is not a parameter group keyed by a string, value \""
+                                + mapEntry.getValue() + "\" in map \"" + fieldName + "\" is not a parameter group");
+            }
+        }
+    }
+
+    /**
+     * Check if this field contains parameter groups.
+     * 
+     * @param fieldName the name of the collection field.
+     * @param collectionObject the collection object to check
+     */
+    private void checkCollection4ParameterGroups(final String fieldName, final Object collectionObject) {
+        if (collectionObject == null) {
+            throw new ParameterRuntimeException("collection parameter \"" + fieldName + "\" is null");
+        }
+
+        Collection<?> collection2Check = (Collection<?>) collectionObject;
+
+        for (Object collectionMember : collection2Check) {
+            if (ParameterGroup.class.isAssignableFrom(collectionMember.getClass())) {
+                throw new ParameterRuntimeException("collection parameter \"" + fieldName + "\" is illegal,"
+                                + " parameter groups are not allowed as collection members");
+            }
+        }
+    }
+
+    /**
+     * Gets the parameter group for this validation result.
+     *
+     * @return the parameter class
+     */
+    public ParameterGroup getParameterGroup() {
+        return parameterGroup;
+    }
+
+    /**
+     * Gets the name of the parameter group being validated.
+     *
+     * @return the name
+     */
+    @Override
+    public String getName() {
+        return parameterGroup.getName();
+    }
+
+    /**
+     * Gets the status of validation.
+     *
+     * @return the status
+     */
+    @Override
+    public ValidationStatus getStatus() {
+        return status;
+    }
+
+    /**
+     * Set the validation result on on a parameter group.
+     * 
+     * @param status The validation status the parameter group is receiving
+     * @param message The validation message explaining the validation status
+     */
+    @Override
+    public void setResult(ValidationStatus status, String message) {
+        setResult(status);
+        this.message = message;
+    }
+
+    /**
+     * Set the validation result on on a parameter group.
+     * 
+     * On a sequence of calls, the most serious validation status is recorded, assuming the status enum ordinal increase
+     * in order of severity
+     * 
+     * @param status The validation status the parameter group is receiving
+     */
+    public void setResult(final ValidationStatus status) {
+        //
+        if (this.status.ordinal() < status.ordinal()) {
+            this.status = status;
+            this.message = ParameterConstants.PARAMETER_GROUP_HAS_STATUS_MESSAGE + status.toString();
+        }
+    }
+
+    /**
+     * Set the validation result on a parameter group.
+     * 
+     * @param parameterGroupName The name of the parameter group
+     * @param status The validation status the field is receiving
+     * @param message The validation message explaining the validation status
+     */
+    public void setResult(final String parameterGroupName, final ValidationStatus status, final String message) {
+        ParameterValidationResult parameterValidationResult;
+        try {
+            parameterValidationResult = (ParameterValidationResult) validationResultMap.get(parameterGroupName);
+        } catch (ClassCastException e) {
+            throw new ParameterRuntimeException("parameter not a regular parameter: " + parameterGroupName, e);
+        }
+
+        if (parameterValidationResult == null) {
+            throw new ParameterRuntimeException(
+                            "no regular parameter field exists for parameter: " + parameterGroupName);
+        }
+
+        // Set the status of the parameter group and the field
+        parameterValidationResult.setResult(status, message);
+        this.setResult(status);
+    }
+
+    /**
+     * Set the validation result on a nested parameter group.
+     * 
+     * @param parameterName The name of the parameter field
+     * @param nestedValidationResult The validation result from a nested field
+     */
+    public void setResult(String parameterName, ValidationResult nestedValidationResult) {
+        GroupValidationResult groupValidationResult;
+        try {
+            groupValidationResult = (GroupValidationResult) validationResultMap.get(parameterName);
+        } catch (ClassCastException e) {
+            throw new ParameterRuntimeException("parameter is not a nested group parameter: " + parameterName, e);
+        }
+
+        if (groupValidationResult == null) {
+            throw new ParameterRuntimeException("no nested parameter field exists for parameter: " + parameterName);
+        }
+
+        // Set the status of the parameter group and replace the field result
+        validationResultMap.put(parameterName, nestedValidationResult);
+        this.setResult(status);
+    }
+
+    /**
+     * Set the validation result on a nested parameter group map entry.
+     * 
+     * @param parameterName The name of the parameter field
+     * @param key The key of the map entry
+     * @param nestedMapValidationResult The validation result from a nested map entry
+     */
+    public void setResult(final String parameterName, final String key,
+                    final ValidationResult nestedMapValidationResult) {
+        GroupMapValidationResult groupMapValidationResult;
+        try {
+            groupMapValidationResult = (GroupMapValidationResult) validationResultMap.get(parameterName);
+        } catch (ClassCastException e) {
+            throw new ParameterRuntimeException("parameter is not a nested group map parameter: " + parameterName, e);
+        }
+
+        if (groupMapValidationResult == null) {
+            throw new ParameterRuntimeException("no group map parameter field exists for parameter: " + parameterName);
+        }
+
+        // Set the status of the parameter group and the field
+        groupMapValidationResult.setResult(key, nestedMapValidationResult);
+        this.setResult(status);
+    }
+
+    /**
+     * Gets the validation result.
+     *
+     * @param initialIndentation the indentation to use on the main result output
+     * @param subIndentation the indentation to use on sub parts of the result output
+     * @param showClean output information on clean fields
+     * @return the result
+     */
+    @Override
+    public String getResult(final String initialIndentation, final String subIndentation, final boolean showClean) {
+        if (status == ValidationStatus.CLEAN && !showClean) {
+            return null;
+        }
+
+        StringBuilder validationResultBuilder = new StringBuilder();
+
+        validationResultBuilder.append(initialIndentation);
+        validationResultBuilder.append("parameter group \"");
+        validationResultBuilder.append(parameterGroup.getName());
+        validationResultBuilder.append("\" type \"");
+        validationResultBuilder.append(parameterGroup.getClass().getCanonicalName());
+        validationResultBuilder.append("\" ");
+        validationResultBuilder.append(status);
+        validationResultBuilder.append(", ");
+        validationResultBuilder.append(message);
+        validationResultBuilder.append('\n');
+
+        for (ValidationResult fieldResult : validationResultMap.values()) {
+            String fieldResultMessage = fieldResult.getResult(initialIndentation + subIndentation, subIndentation,
+                            showClean);
+            if (fieldResultMessage != null) {
+                validationResultBuilder.append(fieldResultMessage);
+            }
+        }
+
+        return validationResultBuilder.toString();
+    }
+}
\ No newline at end of file
diff --git a/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterConstants.java b/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterConstants.java
new file mode 100644
index 00000000..240b1f40
--- /dev/null
+++ b/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterConstants.java
@@ -0,0 +1,45 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * 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.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.parameters;
+
+/**
+ * This static class holds the values of constants for parameter handling.
+ */
+public final class ParameterConstants {
+    // Indentation is 0 on the left and 2 for each level of hierarchy
+    public static final String DEFAULT_INITIAL_RESULT_INDENTATION = "";
+    public static final String DEFAULT_RESULT_INDENTATION = "  ";
+    
+    // By default we do not show validation results for parameters that are validated as clean
+    public static final boolean DO_NOT_SHOW_CLEAN_RESULTS = false;
+    
+    // Messages for clean validations
+    public static final String PARAMETER_GROUP_HAS_STATUS_MESSAGE = "parameter group has status ";
+    public static final String PARAMETER_GROUP_MAP_HAS_STATUS_MESSAGE = "parameter group map has status ";
+    public static final String PARAMETER_HAS_STATUS_MESSAGE       = "parameter has status ";
+    
+    /**
+     * Private constructor to prevent subclassing.
+     */
+    private ParameterConstants() {
+        // Private constructor to prevent subclassing
+    }
+}
\ No newline at end of file
diff --git a/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterException.java b/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterException.java
index 129d5390..3a6e17e8 100644
--- a/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterException.java
+++ b/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterException.java
@@ -55,21 +55,21 @@ public class ParameterException extends Exception {
      * Instantiates a new parameter exception.
      *
      * @param message the message on the exception
-     * @param e the exception that caused this parameter exception
+     * @param exception the exception that caused this parameter exception
      */
-    public ParameterException(final String message, final Exception e) {
-        this(message, e, null);
+    public ParameterException(final String message, final Exception exception) {
+        this(message, exception, null);
     }
 
     /**
      * Instantiates a new parameter exception.
      *
      * @param message the message on the exception
-     * @param e the exception that caused this parameter exception
+     * @param exception the exception that caused this parameter exception
      * @param object the object that the exception was thrown on
      */
-    public ParameterException(final String message, final Exception e, final Object object) {
-        super(message, e);
+    public ParameterException(final String message, final Exception exception, final Object object) {
+        super(message, exception);
         this.object = object;
     }
 
@@ -83,7 +83,7 @@ public class ParameterException extends Exception {
     }
 
     /**
-     * Build a cascaded message from an exception and all its nested exceptions
+     * Build a cascaded message from an exception and all its nested exceptions.
      * 
      * @param throwable the top level exception
      * @return cascaded message string
@@ -101,7 +101,6 @@ public class ParameterException extends Exception {
     }
 
     /**
-     *
      * Get the object on which the exception was thrown.
      *
      * @return The object on which the exception was thrown
diff --git a/common-parameters/src/main/java/org/onap/policy/common/parameters/AbstractParameters.java b/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterGroup.java
index 5430dfeb..48e8379f 100644
--- a/common-parameters/src/main/java/org/onap/policy/common/parameters/AbstractParameters.java
+++ b/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterGroup.java
@@ -1,5 +1,4 @@
-package org.onap.policy.common.parameters;
-/*
+/*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
  * ================================================================================
@@ -19,29 +18,35 @@ package org.onap.policy.common.parameters;
  * ============LICENSE_END=========================================================
  */
 
+package org.onap.policy.common.parameters;
+
 /**
- * This class defines an abstract parameter interface that acts as a base interface for all parameters in the ONAP
- * Policy Framework. All parameter POJOs are subclass of the abstract parameter class and can be used with the
- * {@link ParameterService}.
+ * This interface acts as a base interface for all parameter groups in the ONAP Policy Framework. All parameter group
+ * POJOs are implementations of the parameter group interface and can be used with the {@link ParameterService}.
  *
  * @author Liam Fallon (liam.fallon@ericsson.com)
  */
-public interface AbstractParameters {
+public interface ParameterGroup {
     /**
-     * Gets the parameter class.
-     *
-     * @return the parameter class
+     * Get the group name.
+     * 
+     * @return the group name
      */
-    default Class<? extends AbstractParameters> getParameterClass() {
-        return this.getClass();
-    }
+    public String getName();
+
+    /**
+     * Validate parameters.
+     * 
+     * @return the result of the parameter validation
+     */
+    GroupValidationResult validate();
 
     /**
-     * Gets the parameter class name.
-     *
-     * @return the parameter class name
+     * Check if the parameters are valid.
+     * 
+     * @return true if the parameters are valid
      */
-    default String getParameterClassName() {
-        return this.getClass().getCanonicalName();
+    default boolean isValid() {
+        return validate().getStatus().isValid();
     }
 }
diff --git a/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterRuntimeException.java b/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterRuntimeException.java
index 4b7d5874..071593a9 100644
--- a/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterRuntimeException.java
+++ b/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterRuntimeException.java
@@ -55,21 +55,21 @@ public class ParameterRuntimeException extends RuntimeException {
      * Instantiates a new parameter runtime exception.
      *
      * @param message the message on the exception
-     * @param e the exception that caused this parameter exception
+     * @param exception the exception that caused this parameter exception
      */
-    public ParameterRuntimeException(final String message, final Exception e) {
-        this(message, e, null);
+    public ParameterRuntimeException(final String message, final Exception exception) {
+        this(message, exception, null);
     }
 
     /**
      * Instantiates a new parameter runtime exception.
      *
      * @param message the message on the exception
-     * @param e the exception that caused this parameter exception
+     * @param exception the exception that caused this parameter exception
      * @param object the object that the exception was thrown on
      */
-    public ParameterRuntimeException(final String message, final Exception e, final Object object) {
-        super(message, e);
+    public ParameterRuntimeException(final String message, final Exception exception, final Object object) {
+        super(message, exception);
         this.object = object;
     }
 
diff --git a/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterService.java b/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterService.java
index f411937d..db6995c5 100644
--- a/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterService.java
+++ b/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterService.java
@@ -1,5 +1,4 @@
-package org.onap.policy.common.parameters;
-/*
+/*-
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
  * ================================================================================
@@ -19,25 +18,27 @@ package org.onap.policy.common.parameters;
  * ============LICENSE_END=========================================================
  */
 
+package org.onap.policy.common.parameters;
+
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
 /**
- * The parameter service makes ONAP PF parameters available to all classes in a JVM.
- *
- * The reason for having a parameter service is to avoid having to pass parameters down long call chains in modules such
- * as PDPs and editors. The parameter service makes correct and verified parameters available statically.
- *
- * The parameter service must be used with care because changing a parameter set anywhere in a JVM will affect all users
- * of those parameters anywhere in the JVM.
+ * The parameter service makes ONAP PF parameter groups available to all classes in a JVM.
+ * 
+ * <p>The reason for having a parameter service is to avoid having to pass parameters down long call chains in modules
+ * such as PDPs and editors. The parameter service makes correct and verified parameters available statically.
+ * 
+ * <p>The parameter service must be used with care because changing a parameter set anywhere in a JVM will affect all
+ * users of those parameters anywhere in the JVM.
  *
  * @author Liam Fallon (liam.fallon@ericsson.com)
  */
 public abstract class ParameterService {
     // The map holding the parameters
-    private static Map<Class<? extends AbstractParameters>, AbstractParameters> parameterMap = new ConcurrentHashMap<>();
+    private static Map<String, ParameterGroup> parameterGroupMap = new ConcurrentHashMap<>();
 
     /**
      * This class is an abstract static class that cannot be extended.
@@ -46,69 +47,71 @@ public abstract class ParameterService {
     }
 
     /**
-     * Register parameters with the parameter service.
+     * Register a parameter group with the parameter service.
      *
-     * @param <P> the generic type
-     * @param parametersClass the class of the parameter, used to index the parameter
-     * @param parameters the parameters
+     * @param parameterGroup the parameter group
      */
-    public static <P extends AbstractParameters> void registerParameters(final P parameters) {
-        parameterMap.put(parameters.getClass(), parameters);
+    public static void register(final ParameterGroup parameterGroup) {
+        if (!parameterGroupMap.containsKey(parameterGroup.getName())) {
+            parameterGroupMap.put(parameterGroup.getName(), parameterGroup);
+        } else {
+            throw new ParameterRuntimeException(
+                            "\"" + parameterGroup.getName() + "\" already registered in parameter service");
+        }
     }
 
     /**
-     * Remove parameters from the parameter service.
+     * Remove a parameter group from the parameter service.
      *
-     * @param <P> the generic type
-     * @param parametersClass the class of the parameter, used to index the parameter
+     * @param parameterGroupName the name of the parameter group
      */
-    public static <P extends AbstractParameters> void deregisterParameters(final Class<P> parametersClass) {
-        parameterMap.remove(parametersClass);
+    public static void deregister(final String parameterGroupName) {
+        if (parameterGroupMap.containsKey(parameterGroupName)) {
+            parameterGroupMap.remove(parameterGroupName);
+        } else {
+            throw new ParameterRuntimeException("\"" + parameterGroupName + "\" not registered in parameter service");
+        }
     }
 
     /**
-     * Get parameters from the parameter service.
+     * Get a parameter group from the parameter service.
      *
-     * @param <P> the generic type
-     * @param parametersClass the class of the parameter, used to index the parameter
-     * @return The parameter
+     * @param parameterGroupName the name of the parameter group
+     * @return The parameter group
      */
-    @SuppressWarnings("unchecked")
-    public static <P extends AbstractParameters> P getParameters(final Class<P> parametersClass) {
-        final P parameter = (P) parameterMap.get(parametersClass);
+    public static ParameterGroup get(final String parameterGroupName) {
+        final ParameterGroup parameterGroup = parameterGroupMap.get(parameterGroupName);
 
-        if (parameter == null) {
-            throw new ParameterRuntimeException(
-                            "Parameters for " + parametersClass.getCanonicalName() + " not found in parameter service");
+        if (parameterGroup == null) {
+            throw new ParameterRuntimeException("\"" + parameterGroupName + "\" not found in parameter service");
         }
 
-        return parameter;
+        return parameterGroup;
     }
 
     /**
-     * Check if parameters is defined on the parameter service.
+     * Check if a parameter group is defined on the parameter service.
      *
-     * @param <P> the generic type
-     * @param parametersClass the class of the parameter, used to index the parameter
+     * @param parameterGroupName the name of the parameter group
      * @return true if the parameter is defined
      */
-    public static <P extends AbstractParameters> boolean existsParameters(final Class<P> parametersClass) {
-        return parameterMap.get(parametersClass) != null;
+    public static boolean contains(final String parameterGroupName) {
+        return parameterGroupMap.containsKey(parameterGroupName) && parameterGroupMap.get(parameterGroupName) != null;
     }
 
     /**
-     * Get all the entries in the parameters map.
+     * Get all parameter groups.
      *
      * @return The entries
      */
-    public static Set<Entry<Class<? extends AbstractParameters>, AbstractParameters>> getAll() {
-        return parameterMap.entrySet();
+    public static Set<Entry<String, ParameterGroup>> getAll() {
+        return parameterGroupMap.entrySet();
     }
 
     /**
-     * Clear all parameters in the parameter service.
+     * Clear all parameter groups in the parameter service.
      */
     public static void clear() {
-        parameterMap.clear();
+        parameterGroupMap.clear();
     }
 }
diff --git a/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterValidationResult.java b/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterValidationResult.java
new file mode 100644
index 00000000..9c829f4b
--- /dev/null
+++ b/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterValidationResult.java
@@ -0,0 +1,110 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * 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.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.parameters;
+
+import java.lang.reflect.Field;
+
+/**
+ * This class holds the result of the validation of a parameter.
+ */
+public class ParameterValidationResult implements ValidationResult {
+    // The field and value of the parameter to which the validation result applies
+    private final Field field;
+    private final Object parameterValue;
+
+    // Validation status and message
+    private ValidationStatus status = ValidationStatus.CLEAN;
+    private String message = ParameterConstants.PARAMETER_HAS_STATUS_MESSAGE + status.toString();
+
+    /**
+     * Constructor, create validation result for a parameter with default arguments.
+     *
+     * @param field the parameter field
+     * @param parameterValue the value of the parameter field
+     */
+    protected ParameterValidationResult(final Field field, final Object parameterValue) {
+        this.field = field;
+        this.parameterValue = parameterValue;
+    }
+
+    /**
+     * Gets the name of the parameter being validated.
+     *
+     * @return the name
+     */
+    @Override
+    public String getName() {
+        return field.getName();
+    }
+
+    /**
+     * Gets the validation status.
+     *
+     * @return the validation status
+     */
+    @Override
+    public ValidationStatus getStatus() {
+        return status;
+    }
+
+    /**
+     * Set the validation result on on a parameter field. 
+     * @param status The validation status the field is receiving
+     * @param message The validation message explaining the validation status
+     */
+    @Override
+    public void setResult(final ValidationStatus status, final String message) {
+        this.status = status;
+        this.message = message;
+    }
+
+    /**
+     * Gets the validation result.
+     *
+     * @param initialIndentation the result indentation
+     * @param subIndentation the indentation to use on sub parts of the result output
+     * @param showClean output information on clean fields
+     * @return the result
+     */
+    @Override
+    public String getResult(final String initialIndentation, final String subIndentation, final boolean showClean) {
+        if (status == ValidationStatus.CLEAN && !showClean) {
+            return null;
+        }
+
+        StringBuilder validationResultBuilder = new StringBuilder();
+
+        validationResultBuilder.append(initialIndentation);
+        validationResultBuilder.append("field \"");
+        validationResultBuilder.append(getName());
+        validationResultBuilder.append("\" type \"");
+        validationResultBuilder.append(field.getType().getCanonicalName());
+        validationResultBuilder.append("\" value \"");
+        validationResultBuilder.append(parameterValue);
+        validationResultBuilder.append("\" ");
+        validationResultBuilder.append(getStatus());
+        validationResultBuilder.append(", ");
+        validationResultBuilder.append(message);
+        validationResultBuilder.append('\n');
+
+        return validationResultBuilder.toString();
+    }
+}
diff --git a/common-parameters/src/main/java/org/onap/policy/common/parameters/ValidationResult.java b/common-parameters/src/main/java/org/onap/policy/common/parameters/ValidationResult.java
new file mode 100644
index 00000000..b97ccda0
--- /dev/null
+++ b/common-parameters/src/main/java/org/onap/policy/common/parameters/ValidationResult.java
@@ -0,0 +1,78 @@
+/*-
+ * ============LICENSE_START=======================================================
+ *  Copyright (C) 2018 Ericsson. All rights reserved.
+ * ================================================================================
+ * 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.
+ * 
+ * SPDX-License-Identifier: Apache-2.0
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.parameters;
+
+/**
+ * This interface defines the result of a parameter validation.
+ */
+public interface ValidationResult {
+    /**
+     * Gets the name of the entity being validated.
+     *
+     * @return the name
+     */
+    public String getName();
+
+    /**
+     * Gets the status of validation.
+     *
+     * @return the status
+     */
+    public ValidationStatus getStatus();
+
+    /**
+     * Checks if the result is valid.
+     *
+     * @return true, if is valid
+     */
+    default boolean isValid() {
+        return getStatus().isValid(); 
+    }
+
+    /**
+     * Gets the validation result.
+     *
+     * @return the full validation result
+     */
+    default String getResult() {
+        return getResult(
+                        ParameterConstants.DEFAULT_INITIAL_RESULT_INDENTATION,
+                        ParameterConstants.DEFAULT_RESULT_INDENTATION,
+                        ParameterConstants.DO_NOT_SHOW_CLEAN_RESULTS);
+    }
+
+    /**
+     * Gets the validation result.
+     *
+     * @param initialIndentation the indentation to use on the main result output
+     * @param subIndentation the indentation to use on sub parts of the result output
+     * @param showClean output information on clean fields
+     * @return the result
+     */
+    public String getResult(final String initialIndentation, final String subIndentation, final boolean showClean);
+    
+    /**
+     * Set a validation result. 
+     * @param status The validation status the field is receiving
+     * @param message The validation message explaining the validation status
+     */
+    public void setResult(final ValidationStatus status, final String message);
+}
\ No newline at end of file
diff --git a/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterValidator.java b/common-parameters/src/main/java/org/onap/policy/common/parameters/ValidationStatus.java
index 0d718267..ff453a1b 100644
--- a/common-parameters/src/main/java/org/onap/policy/common/parameters/ParameterValidator.java
+++ b/common-parameters/src/main/java/org/onap/policy/common/parameters/ValidationStatus.java
@@ -20,17 +20,17 @@
 
 package org.onap.policy.common.parameters;
 
-/**
- * This interface is implemented by ONAP PF parameter classes so that they can be validated.
- *
- * @author Liam Fallon (liam.fallon@ericsson.com)
- */
-public interface ParameterValidator {
+public enum ValidationStatus {
+    CLEAN,
+    OBSERVATION,
+    WARNING,
+    INVALID;
+    
     /**
-     * Validate a parameter java bean, if the parameter bean is valid, an empty string is returned,
-     * otherwise the string gives details of the invalid parameters.
-     *
-     * @return the string with validation errors
+     * The result of a validation is valid unless the status is INVALID.
+     * @return true if the validation has passed
      */
-    String validate();
+    public boolean isValid() {
+        return !this.equals(INVALID);
+    }
 }