1 files changed, 108 insertions, 0 deletions
diff --git a/common-parameters/src/main/java/org/onap/policy/common/parameters/ItemValidator.java b/common-parameters/src/main/java/org/onap/policy/common/parameters/ItemValidator.java
new file mode 100644
index 00000000..d0c027c1
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+++ b/common-parameters/src/main/java/org/onap/policy/common/parameters/ItemValidator.java
@@ -0,0 +1,108 @@
+/*-
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2020 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;
+
+import java.lang.annotation.Annotation;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+/**
+ * Validator of an "item", which is typically found in a collection, or the key or value
+ * components of an entry in a Map.
+ */
+public class ItemValidator extends ValueValidator {
+    private final Annotation annotationContainer;
+
+    /**
+     * Constructs the object.
+     *
+     * @param validator provider of validation methods
+     * @param annotationContainer an annotation containing validation annotations to be
+     *        applied to the item
+     */
+    public ItemValidator(BeanValidator validator, Annotation annotationContainer) {
+        this(validator, annotationContainer, true);
+    }
+
+    /**
+     * Constructs the object.
+     *
+     * @param validator provider of validation methods
+     * @param annotationContainer an annotation containing validation annotations to be
+     *        applied to the item
+     * @param addValidators {@code true} if to add validators
+     */
+    public ItemValidator(BeanValidator validator, Annotation annotationContainer, boolean addValidators) {
+        this.annotationContainer = annotationContainer;
+
+        if (addValidators) {
+            validator.addValidators(this);
+        }
+    }
+
+    /**
+     * Gets an annotation from the field or the class.
+     *
+     * @param annotClass annotation class of interest
+     * @return the annotation, or {@code null} if the {@link #annotationContainer} does
+     *         not contain the desired annotation
+     */
+    public <T extends Annotation> T getAnnotation(Class<T> annotClass) {
+        try {
+            for (Method meth : annotationContainer.getClass().getDeclaredMethods()) {
+                T annot = getAnnotation2(annotClass, meth);
+                if (annot != null) {
+                    return annot;
+                }
+            }
+        } catch (RuntimeException | IllegalAccessException | InvocationTargetException e) {
+            throw new IllegalArgumentException("cannot determine " + annotClass.getName(), e);
+        }
+
+        return null;
+    }
+
+    private <T extends Annotation> T getAnnotation2(Class<T> annotClass, Method method)
+                    throws IllegalAccessException, IllegalArgumentException, InvocationTargetException {
+
+        Class<?> ret = method.getReturnType();
+        if (!ret.isArray()) {
+            return null;
+        }
+
+        Class<?> comp = ret.getComponentType();
+        if (comp != annotClass) {
+            return null;
+        }
+
+        // get the array for this type of annotation
+        @SuppressWarnings("unchecked")
+        T[] arrobj = (T[]) method.invoke(annotationContainer);
+
+        if (arrobj.length == 0) {
+            return null;
+        }
+
+        // TODO log if there's more than one item
+
+        return arrobj[0];
+    }
+}