1 files changed, 59 insertions, 0 deletions
diff --git a/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/FieldExtractor.java b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/FieldExtractor.java
new file mode 100644
index 00000000..132b8ed0
--- /dev/null
+++ b/feature-pooling-dmaap/src/main/java/org/onap/policy/drools/pooling/extractor/FieldExtractor.java
@@ -0,0 +1,59 @@
+/*
+ * ============LICENSE_START=======================================================
+ * ONAP
+ * ================================================================================
+ * Copyright (C) 2018 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.drools.pooling.extractor;
+
+import java.lang.reflect.Field;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * Used to extract an object stored in one of the container's fields.
+ */
+public class FieldExtractor implements Extractor {
+
+    private static final Logger logger = LoggerFactory.getLogger(FieldExtractor.class);
+
+    /**
+     * Field containing the object.
+     */
+    private final Field field;
+
+    /**
+     * 
+     * @param field field containing the object
+     */
+    public FieldExtractor(Field field) {
+        this.field = field;
+
+        field.setAccessible(true);
+    }
+
+    @Override
+    public Object extract(Object object) {
+        try {
+            return field.get(object);
+
+        } catch (IllegalAccessException | IllegalArgumentException e) {
+            logger.warn("cannot get {} from {}", field.getName(), object.getClass(), e);
+            return null;
+        }
+    }
+}