Add Tapi Context/Topology/Node/Link builders and utility class

ONOS-7679

Change-Id: I85f856b11a5e272460b38c16ca46212fb4a0a082
diff --git a/apps/odtn/api/src/main/java/org/onosproject/odtn/utils/tapi/TapiGlobalClassUtil.java b/apps/odtn/api/src/main/java/org/onosproject/odtn/utils/tapi/TapiGlobalClassUtil.java
new file mode 100644
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--- /dev/null
+++ b/apps/odtn/api/src/main/java/org/onosproject/odtn/utils/tapi/TapiGlobalClassUtil.java
@@ -0,0 +1,111 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * 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.
+ */
+
+package org.onosproject.odtn.utils.tapi;
+
+import org.onosproject.yang.gen.v1.tapicommon.rev20180307.tapicommon.Uuid;
+import org.onosproject.yang.gen.v1.tapicommon.rev20180307.tapicommon.globalclass.DefaultName;
+import org.onosproject.yang.gen.v1.tapicommon.rev20180307.tapicommon.globalclass.Name;
+import org.onosproject.yang.model.ModelObject;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.UUID;
+
+import org.slf4j.Logger;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Utility methods dealing with TAPI modelObject which includes global class grouping.
+ *
+ * <p> tapi-common@2018-03-07.yang
+ * grouping global-class {
+ *   leaf uuid {
+ *     type uuid;
+ *   }
+ *   list name {
+ *     key 'value-name';
+ *     uses name-and-value;
+ *   }
+ * }
+ *
+ * grouping name-and-value {
+ *   leaf value-name {
+ *     type string;
+ *     description "The name of the value. The value need not have a name.";
+ *   }
+ *   leaf value {
+ *     type string;
+ *     description "The value";
+ *   }
+ *   description "A scoped name-value pair";
+ * }
+ * </p>
+ */
+public final class TapiGlobalClassUtil {
+
+    private static final Logger log = getLogger(TapiGlobalClassUtil.class);
+
+    private TapiGlobalClassUtil() {
+    }
+
+    /**
+     * Generate and set Uuid for the ModelObject.
+     * @param obj ModelObject
+     * @param <T> type of ModelObject
+     * @return generated uuid
+     */
+    public static <T extends ModelObject> Uuid setUuid(T obj) {
+        Uuid uuid = Uuid.of(UUID.randomUUID().toString());
+
+        @SuppressWarnings("unchecked")
+        Class<T> cls = (Class<T>) obj.getClass();
+        try {
+            Method method = cls.getMethod("uuid", Uuid.class);
+            method.invoke(obj, uuid);
+        } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) {
+            log.error("Exception thrown", e);
+        }
+
+        return uuid;
+    }
+
+    /**
+     * Add key-value to the ModelObject as "name-and-value" list.
+     * @param obj ModelObject
+     * @param kvs key-value map
+     * @param <T> type of ModelObject
+     */
+    public static <T extends ModelObject> void setNameList(T obj, Map<String, String> kvs) {
+
+        @SuppressWarnings("unchecked")
+        Class<T> cls = (Class<T>) obj.getClass();
+        try {
+            Method method = cls.getMethod("addToName", Name.class);
+
+            for (Entry<String, String> kv : kvs.entrySet()) {
+                DefaultName prop = new DefaultName();
+                prop.valueName(kv.getKey());
+                prop.value(kv.getValue());
+                method.invoke(obj, prop);
+            }
+        } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException e) {
+            log.error("Exception thrown", e);
+        }
+    }
+}
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