Add REST API for openstackvtap app

Change-Id: I5d7697069d804eeb88eb57cbd845af90764c7a86
diff --git a/apps/openstackvtap/app/src/main/java/org/onosproject/openstackvtap/codec/OpenstackVtapCriterionCodec.java b/apps/openstackvtap/app/src/main/java/org/onosproject/openstackvtap/codec/OpenstackVtapCriterionCodec.java
new file mode 100644
index 0000000..608362b
--- /dev/null
+++ b/apps/openstackvtap/app/src/main/java/org/onosproject/openstackvtap/codec/OpenstackVtapCriterionCodec.java
@@ -0,0 +1,91 @@
+/*
+ * 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.openstackvtap.codec;
+
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import org.onlab.packet.IpAddress;
+import org.onlab.packet.IpPrefix;
+import org.onlab.packet.TpPort;
+import org.onosproject.codec.CodecContext;
+import org.onosproject.codec.JsonCodec;
+import org.onosproject.openstackvtap.api.OpenstackVtapCriterion;
+import org.onosproject.openstackvtap.impl.DefaultOpenstackVtapCriterion;
+
+import static org.onlab.util.Tools.nullIsIllegal;
+import static org.onosproject.openstackvtap.util.OpenstackVtapUtil.getProtocolStringFromType;
+import static org.onosproject.openstackvtap.util.OpenstackVtapUtil.getProtocolTypeFromString;
+
+/**
+ * Openstack vTap codec used for serializing and de-serializing JSON string.
+ */
+public final class OpenstackVtapCriterionCodec extends JsonCodec<OpenstackVtapCriterion> {
+
+    private static final String SRC_IP = "srcIp";
+    private static final String DST_IP = "dstIp";
+    private static final String IP_PROTOCOL = "ipProto";
+    private static final String SRC_PORT = "srcPort";
+    private static final String DST_PORT = "dstPort";
+
+    private static final String MISSING_MESSAGE = " is required in OpenstackVtapCriterion";
+
+    @Override
+    public ObjectNode encode(OpenstackVtapCriterion entity, CodecContext context) {
+        String protoStr = getProtocolStringFromType(entity.ipProtocol());
+
+        return context.mapper().createObjectNode()
+                .put(SRC_IP, entity.srcIpPrefix().address().toString())
+                .put(DST_IP, entity.dstIpPrefix().address().toString())
+                .put(IP_PROTOCOL, protoStr)
+                .put(SRC_PORT, entity.srcTpPort().toString())
+                .put(DST_PORT, entity.dstTpPort().toString());
+    }
+
+    @Override
+    public OpenstackVtapCriterion decode(ObjectNode json, CodecContext context) {
+        if (json == null || !json.isObject()) {
+            return null;
+        }
+
+        OpenstackVtapCriterion.Builder cBuilder = DefaultOpenstackVtapCriterion.builder();
+
+        // parse source IP address
+        IpPrefix srcIp = IpPrefix.valueOf(IpAddress.valueOf(nullIsIllegal(
+                json.get(SRC_IP).asText(), SRC_IP + MISSING_MESSAGE)), 32);
+        // parse destination IP address
+        IpPrefix dstIp = IpPrefix.valueOf(IpAddress.valueOf(nullIsIllegal(
+                json.get(DST_IP).asText(), DST_IP + MISSING_MESSAGE)), 32);
+
+        cBuilder.srcIpPrefix(srcIp);
+        cBuilder.dstIpPrefix(dstIp);
+
+        // parse IP protocol
+        String ipProtoStr = json.get(IP_PROTOCOL).asText();
+        if (ipProtoStr != null) {
+            cBuilder.ipProtocol(getProtocolTypeFromString(ipProtoStr));
+        }
+
+        // parse source port number
+        int srcPort = json.get(SRC_PORT).asInt(0);
+
+        // parse destination port number
+        int dstPort = json.get(DST_PORT).asInt(0);
+
+        cBuilder.srcTpPort(TpPort.tpPort(srcPort));
+        cBuilder.dstTpPort(TpPort.tpPort(dstPort));
+
+        return cBuilder.build();
+    }
+}