Add NotNull and NotBlank parameter validation

Modified the ParameterValidator to support new NotNull and NotBlank
annotations indicating that a field should not be null or blank.
These annotations can be made at class level or individual field level.

Moved annotations to their own subdirectory.
Added a comment to a method.
Extracted constant strings.
Moved one annotation to the subclass level.

Added support for "Min" annotation.

Propagate validation errors up from nested items.  Apply
field-level validations, even when field is a ParameterGroup.

Change-Id: Ic90df55487dc5db7b7b0be5397624d1957904a81
Issue-ID: POLICY-1542
Signed-off-by: Jim Hahn <jrh3@att.com>

5 files changed, 214 insertions, 31 deletions

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
index 283f36b9..6da36c19 100644
--- 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
@@ -1,20 +1,20 @@
-/*-
+/*
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
- *  Modifications Copyright (C) 2018 AT&T Intellectual Property. All rights reserved.
+ *  Modifications Copyright (C) 2018-2019 AT&T Intellectual Property. 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=========================================================
  */
@@ -66,7 +66,7 @@ public class GroupValidationResult implements ValidationResult {
             // Check if a validation result should be added for this declared field
             if (isIncludedField(field)) {
                 // Set a validation result for the field
-                validationResultMap.put(field.getName(), getValidationResult(field, parameterGroup));
+                validationResultMap.put(field.getName(), getSetValidationResult(field, parameterGroup));
             }
         }
 
@@ -75,13 +75,29 @@ public class GroupValidationResult implements ValidationResult {
             // Check if a validation result should be added for this declared field
             if (isIncludedField(field)) {
                 // Set a validation result for the field
-                validationResultMap.putIfAbsent(field.getName(), getValidationResult(field, parameterGroup));
+                validationResultMap.putIfAbsent(field.getName(), getSetValidationResult(field, parameterGroup));
             }
         }
     }
+
+    /**
+     * Construct a validation result for a field, updating "this" status.
+     *
+     * @param field The parameter field
+     * @param ParameterGroup The parameter group containing the field
+     * @return the validation result
+     * @throws Exception on accessing private fields
+     */
+    private ValidationResult getSetValidationResult(Field field, ParameterGroup parameterGroup) {
+        ValidationResult result = getValidationResult(field, parameterGroup);
+        setResult(result.getStatus());
+
+        return result;
+    }
+
     /**
      * Construct a validation result for a field.
-     * 
+     *
      * @param field The parameter field
      * @param ParameterGroup The parameter group containing the field
      * @return the validation result
@@ -92,6 +108,12 @@ public class GroupValidationResult implements ValidationResult {
         final Class<?> fieldType = field.getType();
         final Object fieldObject = getObjectField(parameterGroup, field);
 
+        // perform null checks
+        ParameterValidationResult result = new ParameterValidationResult(field, fieldObject);
+        if (!result.isValid()) {
+            return result;
+        }
+
         // Nested parameter groups are allowed
         if (ParameterGroup.class.isAssignableFrom(fieldType)) {
             return new GroupValidationResult((ParameterGroup) fieldObject);
@@ -106,16 +128,16 @@ public class GroupValidationResult implements ValidationResult {
         // Collections of parameter groups are not allowed
         if (Collection.class.isAssignableFrom(field.getType())) {
             checkCollection4ParameterGroups(fieldName, fieldObject);
-            return new ParameterValidationResult(field, fieldObject);
+            return result;
         }
 
         // It's a regular parameter
-        return new ParameterValidationResult(field, fieldObject);
+        return result;
     }
 
     /**
      * Get the value of a field in an object using a getter found with reflection.
-     * 
+     *
      * @param targetObject The object on which to read the field value
      * @param fieldName The name of the field
      * @return The field value
@@ -156,7 +178,7 @@ public class GroupValidationResult implements ValidationResult {
 
     /**
      * 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
      */
@@ -184,7 +206,7 @@ public class GroupValidationResult implements ValidationResult {
 
     /**
      * Check if this field contains parameter groups.
-     * 
+     *
      * @param fieldName the name of the collection field.
      * @param collectionObject the collection object to check
      */
@@ -234,7 +256,7 @@ public class GroupValidationResult implements ValidationResult {
 
     /**
      * Set the validation result on a parameter group.
-     * 
+     *
      * @param status The validation status the parameter group is receiving
      * @param message The validation message explaining the validation status
      */
@@ -247,7 +269,7 @@ public class GroupValidationResult implements ValidationResult {
     /**
      * Set the validation result 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) {
@@ -260,7 +282,7 @@ public class GroupValidationResult implements ValidationResult {
 
     /**
      * Set the validation result on a parameter in a parameter group.
-     * 
+     *
      * @param parameterName The name of the parameter
      * @param status The validation status the field is receiving
      * @param message The validation message explaining the validation status
@@ -281,7 +303,7 @@ public class GroupValidationResult implements ValidationResult {
 
     /**
      * 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
      */
@@ -304,7 +326,7 @@ public class GroupValidationResult implements ValidationResult {
 
     /**
      * 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
@@ -329,7 +351,7 @@ public class GroupValidationResult implements ValidationResult {
 
     /**
      * Set the validation status on a group map entry.
-     * 
+     *
      * @param parameterName The name of the parameter field
      * @param key The key of the map entry
      * @param status The validation status of the entry
@@ -395,11 +417,11 @@ public class GroupValidationResult implements ValidationResult {
 
         return validationResultBuilder.toString();
     }
-    
+
 
     /**
      * Check if a field should be included for validation.
-     * 
+     *
      * @param field the field to check for inclusion
      * @return true of the field should be included
      */
@@ -425,11 +447,11 @@ public class GroupValidationResult implements ValidationResult {
                     superclassFields.add(field);
                 }
             }
-            
+
             // Check the next super class down
             currentClass = currentClass.getSuperclass();
         }
-        
+
         return superclassFields;
     }
-}
\ No newline at end of file
+}
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
index 9c829f4b..e43c2d17 100644
--- 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
@@ -1,26 +1,31 @@
-/*-
+/*
  * ============LICENSE_START=======================================================
  *  Copyright (C) 2018 Ericsson. All rights reserved.
+ *  Modifications Copyright (C) 2019 AT&T Intellectual Property. 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.annotation.Annotation;
 import java.lang.reflect.Field;
+import org.onap.policy.common.parameters.annotations.Min;
+import org.onap.policy.common.parameters.annotations.NotBlank;
+import org.onap.policy.common.parameters.annotations.NotNull;
 
 /**
  * This class holds the result of the validation of a parameter.
@@ -43,6 +48,47 @@ public class ParameterValidationResult implements ValidationResult {
     protected ParameterValidationResult(final Field field, final Object parameterValue) {
         this.field = field;
         this.parameterValue = parameterValue;
+
+        if (parameterValue == null && getAnyAnnotation(field, NotNull.class) != null) {
+            setResult(ValidationStatus.INVALID, "is null");
+
+        } else if (parameterValue instanceof String && getAnyAnnotation(field, NotBlank.class) != null
+                        && parameterValue.toString().trim().isEmpty()) {
+            setResult(ValidationStatus.INVALID, "must be a non-blank string");
+
+        } else if (parameterValue instanceof Number) {
+            Min minAnnot = field.getAnnotation(Min.class);
+            if (minAnnot != null && ((Number) parameterValue).longValue() < minAnnot.value()) {
+                setResult(ValidationStatus.INVALID, "must be >= " + minAnnot.value());
+            }
+        }
+    }
+
+    /**
+     * Gets an annotation for a field, first checking the field, itself, and then checking
+     * at the class level for the current and superclasses.
+     *
+     * @param field field of interest
+     * @param annotClass class of annotation that is desired
+     * @return the field's annotation, or {@code null} if it does not exist
+     */
+    private static <T extends Annotation> T getAnyAnnotation(final Field field, Class<T> annotClass) {
+        T annot = field.getAnnotation(annotClass);
+        if (annot != null) {
+            return annot;
+        }
+
+        // check class level
+        Class<?> clazz = field.getDeclaringClass();
+        while (clazz != Object.class) {
+            if ((annot = clazz.getAnnotation(annotClass)) != null) {
+                return annot;
+            }
+
+            clazz = clazz.getSuperclass();
+        }
+
+        return null;
     }
 
     /**
@@ -66,14 +112,16 @@ public class ParameterValidationResult implements ValidationResult {
     }
 
     /**
-     * Set the validation result on on a parameter field. 
+     * 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;
+        if (this.status == ValidationStatus.CLEAN) {
+            this.status = status;
+            this.message = message;
+        }
     }
 
     /**
diff --git a/common-parameters/src/main/java/org/onap/policy/common/parameters/annotations/Min.java b/common-parameters/src/main/java/org/onap/policy/common/parameters/annotations/Min.java
new file mode 100644
index 00000000..9ad6d7e0
--- /dev/null
+++ b/common-parameters/src/main/java/org/onap/policy/common/parameters/annotations/Min.java
@@ -0,0 +1,39 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2019 AT&T Intellectual Property. 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.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.parameters.annotations;
+
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+@Retention(RUNTIME)
+@Target(FIELD)
+public @interface Min {
+
+    /**
+     * The minimum value allowed.
+     *
+     * @return the minimum value allowed
+     */
+    long value();
+}
diff --git a/common-parameters/src/main/java/org/onap/policy/common/parameters/annotations/NotBlank.java b/common-parameters/src/main/java/org/onap/policy/common/parameters/annotations/NotBlank.java
new file mode 100644
index 00000000..169fa593
--- /dev/null
+++ b/common-parameters/src/main/java/org/onap/policy/common/parameters/annotations/NotBlank.java
@@ -0,0 +1,37 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2019 AT&T Intellectual Property. 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.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.parameters.annotations;
+
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.ElementType.TYPE;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+/**
+ * Indicates that a field (i.e., String) may not be empty.
+ */
+@Retention(RUNTIME)
+@Target({TYPE, FIELD})
+public @interface NotBlank {
+
+}
diff --git a/common-parameters/src/main/java/org/onap/policy/common/parameters/annotations/NotNull.java b/common-parameters/src/main/java/org/onap/policy/common/parameters/annotations/NotNull.java
new file mode 100644
index 00000000..3c7bc8b7
--- /dev/null
+++ b/common-parameters/src/main/java/org/onap/policy/common/parameters/annotations/NotNull.java
@@ -0,0 +1,37 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2019 AT&T Intellectual Property. 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.
+ * ============LICENSE_END=========================================================
+ */
+
+package org.onap.policy.common.parameters.annotations;
+
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.ElementType.TYPE;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+/**
+ * Indicates that a field may not be null.
+ */
+@Retention(RUNTIME)
+@Target({TYPE, FIELD})
+public @interface NotNull {
+
+}