'Static data model implementation in Worklet

Change-Id: Ic5eeb26eaea547523befd509f9f48281cb4c2031
diff --git a/apps/workflow/api/src/main/java/org/onosproject/workflow/api/DefaultWorkletDescription.java b/apps/workflow/api/src/main/java/org/onosproject/workflow/api/DefaultWorkletDescription.java
new file mode 100644
index 0000000..82bb3f8
--- /dev/null
+++ b/apps/workflow/api/src/main/java/org/onosproject/workflow/api/DefaultWorkletDescription.java
@@ -0,0 +1,170 @@
+/*
+ * Copyright 2019-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.workflow.api;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import com.google.common.base.MoreObjects;
+import org.slf4j.Logger;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Class for default worklet description.
+ */
+public final class DefaultWorkletDescription implements WorkletDescription {
+
+    protected static final Logger log = getLogger(DefaultWorkletDescription.class);
+
+    /**
+     * worklet Name.
+     */
+    private String tag;
+
+    /**
+     * worklet data model.
+     */
+    private JsonDataModelTree data;
+
+    /**
+     * Constructor of worklet description.
+     *
+     * @param builder worklet description builder
+     */
+    public DefaultWorkletDescription(DefaultWorkletDescription.Builder builder) {
+        this.tag = builder.tag;
+        this.data = builder.data;
+    }
+
+    public DefaultWorkletDescription(String tag) {
+        this.tag = tag;
+    }
+
+    @Override
+    public String tag() {
+        return this.tag;
+    }
+
+    @Override
+    public JsonDataModelTree data() {
+        return this.data;
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(getClass())
+                .add("tag", tag())
+                .add("data", data())
+                .toString();
+    }
+
+    /**
+     * Gets builder instance.
+     *
+     * @return builder instance
+     */
+    public static DefaultWorkletDescription.Builder builder() {
+        return new DefaultWorkletDescription.Builder();
+    }
+
+    /**
+     * Builder for worklet description.
+     */
+    public static class Builder {
+
+        /**
+         * worklet name.
+         */
+        private String tag;
+
+        /**
+         * static data model tree.
+         */
+        JsonDataModelTree data = new JsonDataModelTree();
+
+        /**
+         * Sets worklet name.
+         *
+         * @param tag worklet name
+         * @return builder
+         */
+        public DefaultWorkletDescription.Builder name(String tag) {
+            this.tag = tag;
+            return this;
+        }
+
+
+        public DefaultWorkletDescription.Builder staticDataModel(String path, String value) throws WorkflowException {
+
+            data.setAt(path, value);
+
+            return this;
+        }
+
+        public DefaultWorkletDescription.Builder staticDataModel(String path, Integer value) throws WorkflowException {
+
+            data.setAt(path, value);
+
+            return this;
+        }
+
+        public DefaultWorkletDescription.Builder staticDataModel(String path, Boolean value) throws WorkflowException {
+
+            data.setAt(path, value);
+
+            return this;
+        }
+
+        public DefaultWorkletDescription.Builder staticDataModel(String path, JsonNode value) throws WorkflowException {
+
+            data.setAt(path, value);
+
+            return this;
+        }
+
+        public DefaultWorkletDescription.Builder staticDataModel(String path, ArrayNode value)
+                throws WorkflowException {
+
+            data.setAt(path, value);
+
+            return this;
+        }
+
+        public DefaultWorkletDescription.Builder staticDataModel(String path, ObjectNode value)
+                throws WorkflowException {
+
+            data.setAt(path, value);
+
+            return this;
+        }
+
+
+        /**
+         * Builds worklet description from builder.
+         *
+         * @return instance of worklet description
+         * @throws WorkflowException workflow exception
+         */
+        public DefaultWorkletDescription build() {
+
+            return new DefaultWorkletDescription(this);
+        }
+
+
+    }
+}