[ONOS-5465][TE Tunnel SB Provider] Interaction with ONOS core TE subsystems for TE tunnel updates

Change-Id: I2cb7ed7731192228a5f6ef4c4b6c3a14a7175732
diff --git a/providers/ietfte/utils/src/main/java/org/onosproject/provider/te/utils/CodecTools.java b/providers/ietfte/utils/src/main/java/org/onosproject/provider/te/utils/CodecTools.java
new file mode 100644
index 0000000..d5213ae
--- /dev/null
+++ b/providers/ietfte/utils/src/main/java/org/onosproject/provider/te/utils/CodecTools.java
@@ -0,0 +1,95 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * 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.provider.te.utils;
+
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.ObjectWriter;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import org.slf4j.Logger;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import static org.slf4j.LoggerFactory.getLogger;
+
+
+/**
+ * Convert utility methods for IETF SB.
+ */
+public final class CodecTools {
+    private static final Logger log = getLogger(CodecTools.class);
+    private static final ObjectMapper MAPPER = new ObjectMapper();
+
+    //no instantiation
+    private CodecTools() {
+    }
+
+    /**
+     * Returns an object node from a InputStream type input which usually comes
+     * from the HTTP response.
+     *
+     * @param stream stream data comes from a HTTP response
+     * @return object node
+     */
+    public static ObjectNode toJson(InputStream stream) {
+        ObjectNode response = null;
+        try {
+            response = (ObjectNode) MAPPER.readTree(stream);
+        } catch (IOException e) {
+            log.error("Parse json string failed {}", e.getMessage());
+        }
+
+        return response;
+    }
+
+    /**
+     * Returns an object node from a string.
+     *
+     * @param jsonString string with JSON format
+     * @return object node
+     */
+    public static ObjectNode toJson(String jsonString) {
+        ObjectNode response = null;
+        try {
+            response = (ObjectNode) MAPPER.readTree(jsonString);
+        } catch (IOException e) {
+            log.error("Parse json string failed {}", e.getMessage());
+        }
+
+        return response;
+    }
+
+    /**
+     * Returns a JSON format string from a Jackson object node.
+     *
+     * @param node JSON object node
+     * @return string with JSON format
+     */
+    public static String jsonToString(ObjectNode node) {
+        ObjectWriter ow = new ObjectMapper().writer().withDefaultPrettyPrinter();
+        String jsonString = null;
+        try {
+            jsonString = ow.writeValueAsString(node);
+        } catch (JsonProcessingException e) {
+            log.error("Parse json to string failed {}", e.getMessage());
+        }
+
+        return jsonString;
+    }
+}