[ONOS-2225] Add codecs with unit test for FlowObjective REST API

* Add codec for FilteringObjective
* Add codec for ForwardingObjective
* Add codec for NextObjective

Change-Id: I715aa7f1969697468692459052fd27cc65ca2363
diff --git a/core/common/src/main/java/org/onosproject/codec/impl/CodecManager.java b/core/common/src/main/java/org/onosproject/codec/impl/CodecManager.java
index 633a356..7c19202 100644
--- a/core/common/src/main/java/org/onosproject/codec/impl/CodecManager.java
+++ b/core/common/src/main/java/org/onosproject/codec/impl/CodecManager.java
@@ -43,6 +43,9 @@
 import org.onosproject.net.flow.TrafficTreatment;
 import org.onosproject.net.flow.criteria.Criterion;
 import org.onosproject.net.flow.instructions.Instruction;
+import org.onosproject.net.flowobjective.FilteringObjective;
+import org.onosproject.net.flowobjective.ForwardingObjective;
+import org.onosproject.net.flowobjective.NextObjective;
 import org.onosproject.net.group.Group;
 import org.onosproject.net.group.GroupBucket;
 import org.onosproject.net.intent.ConnectivityIntent;
@@ -109,6 +112,9 @@
         registerCodec(TableStatisticsEntry.class, new TableStatisticsEntryCodec());
         registerCodec(PortStatistics.class, new PortStatisticsCodec());
         registerCodec(Metric.class, new MetricCodec());
+        registerCodec(FilteringObjective.class, new FilteringObjectiveCodec());
+        registerCodec(ForwardingObjective.class, new ForwardingObjectiveCodec());
+        registerCodec(NextObjective.class, new NextObjectiveCodec());
         log.info("Started");
     }
 
diff --git a/core/common/src/main/java/org/onosproject/codec/impl/FilteringObjectiveCodec.java b/core/common/src/main/java/org/onosproject/codec/impl/FilteringObjectiveCodec.java
new file mode 100644
index 0000000..4cbfffa
--- /dev/null
+++ b/core/common/src/main/java/org/onosproject/codec/impl/FilteringObjectiveCodec.java
@@ -0,0 +1,182 @@
+/*
+ * Copyright 2016 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.codec.impl;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import org.onosproject.codec.CodecContext;
+import org.onosproject.codec.JsonCodec;
+import org.onosproject.core.ApplicationId;
+import org.onosproject.core.CoreService;
+import org.onosproject.net.flow.TrafficTreatment;
+import org.onosproject.net.flow.criteria.Criterion;
+import org.onosproject.net.flowobjective.DefaultFilteringObjective;
+import org.onosproject.net.flowobjective.FilteringObjective;
+import org.slf4j.Logger;
+
+import java.util.stream.IntStream;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static org.onlab.util.Tools.nullIsIllegal;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Filtering Objective Codec.
+ */
+public class FilteringObjectiveCodec extends JsonCodec<FilteringObjective> {
+    private final Logger log = getLogger(getClass());
+
+    // JSON field names
+    private static final String ID = "id";
+    private static final String TYPE = "type";
+    private static final String KEY = "key";
+    private static final String META = "meta";
+    private static final String OPERATION = "operation";
+    private static final String CONDITIONS = "conditions";
+
+    // messages to be printed out
+    private static final String MISSING_MEMBER_MESSAGE =
+            " member is required in FilteringObjective";
+    private static final String NOT_NULL_MESSAGE =
+            "FilteringObjective cannot be null";
+    private static final String INVALID_TYPE_MESSAGE =
+            "The requested type {} is not defined in FilteringObjective.";
+    private static final String INVALID_OP_MESSAGE =
+            "The requested operation {} is not defined for FilteringObjective.";
+
+    public static final String REST_APP_ID = "org.onosproject.rest";
+
+    @Override
+    public ObjectNode encode(FilteringObjective filteringObjective, CodecContext context) {
+
+        checkNotNull(filteringObjective, NOT_NULL_MESSAGE);
+
+        final JsonCodec<Criterion> criterionCodec = context.codec(Criterion.class);
+        final JsonCodec<TrafficTreatment> trafficTreatmentCodec = context.codec(TrafficTreatment.class);
+
+        // encode common properties
+        ObjectiveCodecHelper och = new ObjectiveCodecHelper();
+        ObjectNode result = och.encode(filteringObjective, context);
+
+        // encode id
+        result.put(ID, filteringObjective.id());
+
+        // encode type
+        result.put(TYPE, filteringObjective.type().toString());
+
+        // encode key
+        if (filteringObjective.key() != null) {
+            ObjectNode criterionNode = criterionCodec.encode(filteringObjective.key(), context);
+            result.set(KEY, criterionNode);
+        }
+
+        // encode meta
+        if (filteringObjective.meta() != null) {
+            ObjectNode trafficTreatmentNode = trafficTreatmentCodec.encode(filteringObjective.meta(), context);
+            result.set(META, trafficTreatmentNode);
+        }
+
+        // encode conditions
+        ArrayNode conditions = context.mapper().createArrayNode();
+        filteringObjective.conditions().forEach(c -> {
+            ObjectNode criterionJson = criterionCodec.encode(c, context);
+            conditions.add(criterionJson);
+        });
+        result.set(CONDITIONS, conditions);
+
+        return result;
+    }
+
+    @Override
+    public FilteringObjective decode(ObjectNode json, CodecContext context) {
+        if (json == null || !json.isObject()) {
+            return null;
+        }
+
+        CoreService coreService = context.getService(CoreService.class);
+
+        final JsonCodec<Criterion> criterionCodec = context.codec(Criterion.class);
+        final JsonCodec<TrafficTreatment> trafficTreatmentCodec = context.codec(TrafficTreatment.class);
+
+        ObjectiveCodecHelper och = new ObjectiveCodecHelper();
+
+        DefaultFilteringObjective.Builder baseBuilder = DefaultFilteringObjective.builder();
+        final DefaultFilteringObjective.Builder builder =
+                (DefaultFilteringObjective.Builder) och.decode(json, baseBuilder, context);
+
+        // application id
+        ApplicationId appId = coreService.registerApplication(REST_APP_ID);
+        builder.fromApp(appId);
+
+        // decode type
+        String typeStr = nullIsIllegal(json.get(TYPE), TYPE + MISSING_MEMBER_MESSAGE).asText();
+
+        switch (typeStr) {
+            case "PERMIT":
+                builder.permit();
+                break;
+            case "DENY":
+                builder.deny();
+                break;
+            default:
+                log.warn(INVALID_TYPE_MESSAGE, typeStr);
+                return null;
+        }
+
+        // decode key
+        JsonNode keyJson = json.get(KEY);
+        if (keyJson != null) {
+            Criterion key = criterionCodec.decode((ObjectNode) keyJson, context);
+            builder.withKey(key);
+        }
+
+        // decode conditions
+        JsonNode conditionsJson = json.get(CONDITIONS);
+        checkNotNull(conditionsJson);
+        if (conditionsJson != null) {
+            IntStream.range(0, conditionsJson.size()).forEach(i -> {
+                ObjectNode conditionJson = get(conditionsJson, i);
+                builder.addCondition(criterionCodec.decode(conditionJson, context));
+            });
+        }
+
+        // decode meta
+        JsonNode metaJson = json.get(META);
+        if (metaJson != null) {
+            TrafficTreatment trafficTreatment = trafficTreatmentCodec.decode((ObjectNode) metaJson, context);
+            builder.withMeta(trafficTreatment);
+        }
+
+        // decode operation
+        String opStr = nullIsIllegal(json.get(OPERATION), OPERATION + MISSING_MEMBER_MESSAGE).asText();
+        FilteringObjective filteringObjective;
+
+        switch (opStr) {
+            case "ADD":
+                filteringObjective = builder.add();
+                break;
+            case "REMOVE":
+                filteringObjective = builder.remove();
+                break;
+            default:
+                log.warn(INVALID_OP_MESSAGE, opStr);
+                return null;
+        }
+
+        return filteringObjective;
+    }
+}
diff --git a/core/common/src/main/java/org/onosproject/codec/impl/ForwardingObjectiveCodec.java b/core/common/src/main/java/org/onosproject/codec/impl/ForwardingObjectiveCodec.java
new file mode 100644
index 0000000..d053790
--- /dev/null
+++ b/core/common/src/main/java/org/onosproject/codec/impl/ForwardingObjectiveCodec.java
@@ -0,0 +1,174 @@
+/*
+ * Copyright 2016 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.codec.impl;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import org.onosproject.codec.CodecContext;
+import org.onosproject.codec.JsonCodec;
+import org.onosproject.core.ApplicationId;
+import org.onosproject.core.CoreService;
+import org.onosproject.net.flow.TrafficSelector;
+import org.onosproject.net.flow.TrafficTreatment;
+import org.onosproject.net.flowobjective.DefaultForwardingObjective;
+import org.onosproject.net.flowobjective.ForwardingObjective;
+import org.slf4j.Logger;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static org.onlab.util.Tools.nullIsIllegal;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Forwarding Objective Codec.
+ */
+public class ForwardingObjectiveCodec extends JsonCodec<ForwardingObjective> {
+    private final Logger log = getLogger(getClass());
+
+    // JSON field names
+    private static final String ID = "id";
+    private static final String SELECTOR = "selector";
+    private static final String FLAG = "flag";
+    private static final String OPERATION = "operation";
+    private static final String NEXT_ID = "nextId";
+    private static final String TREATMENT = "treatment";
+
+    // messages to be printed out
+    private static final String MISSING_MEMBER_MESSAGE =
+            " member is required in ForwardingObjective";
+    private static final String NOT_NULL_MESSAGE =
+            "ForwardingObjective cannot be null";
+    private static final String INVALID_FLAG_MESSAGE =
+            "The requested flag {} is not defined in ForwardingObjective.";
+    private static final String INVALID_OP_MESSAGE =
+            "The requested operation {} is not defined for FilteringObjective.";
+
+    public static final String REST_APP_ID = "org.onosproject.rest";
+
+    @Override
+    public ObjectNode encode(ForwardingObjective forwardingObjective, CodecContext context) {
+
+        checkNotNull(forwardingObjective, NOT_NULL_MESSAGE);
+
+        final JsonCodec<TrafficTreatment> trafficTreatmentCodec = context.codec(TrafficTreatment.class);
+        final JsonCodec<TrafficSelector> trafficSelectorCodec = context.codec(TrafficSelector.class);
+
+        // encode common properties
+        ObjectiveCodecHelper och = new ObjectiveCodecHelper();
+        ObjectNode result = och.encode(forwardingObjective, context);
+
+        // encode id
+        result.put(ID, forwardingObjective.id());
+
+        // encode flag
+        result.put(FLAG, forwardingObjective.flag().toString());
+
+        // encode op
+        result.put(OPERATION, forwardingObjective.op().toString());
+
+        // encode selector
+        ObjectNode trafficSelectorNode =
+                trafficSelectorCodec.encode(forwardingObjective.selector(), context);
+        result.set(SELECTOR, trafficSelectorNode);
+
+        // encode nextId
+        if (forwardingObjective.nextId() != null) {
+            result.put(NEXT_ID, forwardingObjective.nextId());
+        }
+
+        // encode treatment
+        if (forwardingObjective.treatment() != null) {
+            ObjectNode trafficTreatmentNode =
+                    trafficTreatmentCodec.encode(forwardingObjective.treatment(), context);
+            result.set(TREATMENT, trafficTreatmentNode);
+        }
+
+        return result;
+    }
+
+    @Override
+    public ForwardingObjective decode(ObjectNode json, CodecContext context) {
+        if (json == null || !json.isObject()) {
+            return null;
+        }
+
+        CoreService coreService = context.getService(CoreService.class);
+
+        final JsonCodec<TrafficTreatment> trafficTreatmentCodec = context.codec(TrafficTreatment.class);
+        final JsonCodec<TrafficSelector> trafficSelectorCodec = context.codec(TrafficSelector.class);
+
+        ObjectiveCodecHelper och = new ObjectiveCodecHelper();
+
+        DefaultForwardingObjective.Builder baseBuilder = DefaultForwardingObjective.builder();
+        final DefaultForwardingObjective.Builder builder =
+                (DefaultForwardingObjective.Builder) och.decode(json, baseBuilder, context);
+
+        // application id
+        ApplicationId appId = coreService.registerApplication(REST_APP_ID);
+        builder.fromApp(appId);
+
+        // decode flag
+        String flagStr = nullIsIllegal(json.get(FLAG), FLAG + MISSING_MEMBER_MESSAGE).asText();
+        switch (flagStr) {
+            case "SPECIFIC":
+                builder.withFlag(ForwardingObjective.Flag.SPECIFIC);
+                break;
+            case "VERSATILE":
+                builder.withFlag(ForwardingObjective.Flag.VERSATILE);
+                break;
+            default:
+                log.warn(INVALID_FLAG_MESSAGE, flagStr);
+                return null;
+        }
+
+        // decode selector
+        JsonNode selectorJson = json.get(SELECTOR);
+        if (selectorJson != null) {
+            TrafficSelector trafficSelector = trafficSelectorCodec.decode((ObjectNode) selectorJson, context);
+            builder.withSelector(trafficSelector);
+        }
+
+        // decode treatment
+        JsonNode treatmentJson = json.get(TREATMENT);
+        if (treatmentJson != null) {
+            TrafficTreatment trafficTreatment = trafficTreatmentCodec.decode((ObjectNode) treatmentJson, context);
+            builder.withTreatment(trafficTreatment);
+        }
+
+        // decode nextId
+        JsonNode nextIdJson = json.get(NEXT_ID);
+        if (nextIdJson != null) {
+            builder.nextStep(nextIdJson.asInt());
+        }
+
+        // decode operation
+        String opStr = nullIsIllegal(json.get(OPERATION), OPERATION + MISSING_MEMBER_MESSAGE).asText();
+        ForwardingObjective forwardingObjective;
+
+        switch (opStr) {
+            case "ADD":
+                forwardingObjective = builder.add();
+                break;
+            case "REMOVE":
+                forwardingObjective = builder.remove();
+                break;
+            default:
+                log.warn(INVALID_OP_MESSAGE, opStr);
+                return null;
+        }
+
+        return forwardingObjective;
+    }
+}
diff --git a/core/common/src/main/java/org/onosproject/codec/impl/NextObjectiveCodec.java b/core/common/src/main/java/org/onosproject/codec/impl/NextObjectiveCodec.java
new file mode 100644
index 0000000..cd75ae7
--- /dev/null
+++ b/core/common/src/main/java/org/onosproject/codec/impl/NextObjectiveCodec.java
@@ -0,0 +1,183 @@
+/*
+ * Copyright 2016 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.codec.impl;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import org.onosproject.codec.CodecContext;
+import org.onosproject.codec.JsonCodec;
+import org.onosproject.core.ApplicationId;
+import org.onosproject.core.CoreService;
+import org.onosproject.net.flow.TrafficSelector;
+import org.onosproject.net.flow.TrafficTreatment;
+import org.onosproject.net.flowobjective.DefaultNextObjective;
+import org.onosproject.net.flowobjective.NextObjective;
+import org.slf4j.Logger;
+
+import java.util.stream.IntStream;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+import static org.onlab.util.Tools.nullIsIllegal;
+import static org.slf4j.LoggerFactory.getLogger;
+
+/**
+ * Next Objective Codec.
+ */
+public class NextObjectiveCodec extends JsonCodec<NextObjective> {
+
+    private final Logger log = getLogger(getClass());
+
+    // JSON field names
+    private static final String ID = "id";
+    private static final String TYPE = "type";
+    private static final String OPERATION = "operation";
+    private static final String TREATMENTS = "treatments";
+    private static final String META = "meta";
+
+    // messages to be printed out
+    private static final String MISSING_MEMBER_MESSAGE =
+            " member is required in NextObjective";
+    private static final String NOT_NULL_MESSAGE =
+            "NextObjective cannot be null";
+    private static final String INVALID_TYPE_MESSAGE =
+            "The requested flag {} is not defined in NextObjective.";
+    private static final String INVALID_OP_MESSAGE =
+            "The requested operation {} is not defined for NextObjective.";
+
+    public static final String REST_APP_ID = "org.onosproject.rest";
+
+    @Override
+    public ObjectNode encode(NextObjective nextObjective, CodecContext context) {
+
+        checkNotNull(nextObjective, NOT_NULL_MESSAGE);
+
+        final JsonCodec<TrafficTreatment> trafficTreatmentCodec = context.codec(TrafficTreatment.class);
+        final JsonCodec<TrafficSelector> trafficSelectorCodec = context.codec(TrafficSelector.class);
+
+        // encode common properties
+        ObjectiveCodecHelper och = new ObjectiveCodecHelper();
+        ObjectNode result = och.encode(nextObjective, context);
+
+        // encode id
+        result.put(ID, nextObjective.id());
+
+        // encode type
+        result.put(TYPE, nextObjective.type().toString());
+
+        // encode operation
+        result.put(OPERATION, nextObjective.op().toString());
+
+        // encode treatments
+        ArrayNode treatments = context.mapper().createArrayNode();
+        nextObjective.next().forEach(t -> {
+            ObjectNode treatmentJson = trafficTreatmentCodec.encode(t, context);
+            treatments.add(treatmentJson);
+        });
+        result.set(TREATMENTS, treatments);
+
+        // encode meta
+        if (nextObjective.meta() != null) {
+            ObjectNode trafficSelectorNode = trafficSelectorCodec.encode(nextObjective.meta(), context);
+            result.set(META, trafficSelectorNode);
+        }
+
+        return result;
+    }
+
+    @Override
+    public NextObjective decode(ObjectNode json, CodecContext context) {
+        if (json == null || !json.isObject()) {
+            return null;
+        }
+
+        CoreService coreService = context.getService(CoreService.class);
+
+        final JsonCodec<TrafficSelector> trafficSelectorCodec = context.codec(TrafficSelector.class);
+        final JsonCodec<TrafficTreatment> trafficTreatmentCodec = context.codec(TrafficTreatment.class);
+
+        ObjectiveCodecHelper och = new ObjectiveCodecHelper();
+
+        DefaultNextObjective.Builder baseBuilder = DefaultNextObjective.builder();
+        final DefaultNextObjective.Builder builder =
+                (DefaultNextObjective.Builder) och.decode(json, baseBuilder, context);
+
+        // decode id
+        JsonNode idJson = json.get(ID);
+        checkNotNull(idJson);
+        builder.withId(idJson.asInt());
+
+        // decode application id
+        ApplicationId appId = coreService.registerApplication(REST_APP_ID);
+        builder.fromApp(appId);
+
+        // decode type
+        String typeStr = nullIsIllegal(json.get(TYPE), TYPE + MISSING_MEMBER_MESSAGE).asText();
+
+        switch (typeStr) {
+            case "HASHED":
+                builder.withType(NextObjective.Type.HASHED);
+                break;
+            case "BROADCAST":
+                builder.withType(NextObjective.Type.BROADCAST);
+                break;
+            case "FAILOVER":
+                builder.withType(NextObjective.Type.FAILOVER);
+                break;
+            case "SIMPLE":
+                builder.withType(NextObjective.Type.SIMPLE);
+                break;
+            default:
+                log.warn(INVALID_TYPE_MESSAGE, typeStr);
+                return null;
+        }
+
+        // decode treatments
+        JsonNode treatmentsJson = json.get(TREATMENTS);
+        checkNotNull(treatmentsJson);
+        if (treatmentsJson != null) {
+            IntStream.range(0, treatmentsJson.size()).forEach(i -> {
+                ObjectNode treatmentJson = get(treatmentsJson, i);
+                builder.addTreatment(trafficTreatmentCodec.decode(treatmentJson, context));
+            });
+        }
+
+        // decode meta
+        JsonNode metaJson = json.get(META);
+        if (metaJson != null) {
+            TrafficSelector trafficSelector = trafficSelectorCodec.decode((ObjectNode) metaJson, context);
+            builder.withMeta(trafficSelector);
+        }
+
+        // decode operation
+        String opStr = nullIsIllegal(json.get(OPERATION), OPERATION + MISSING_MEMBER_MESSAGE).asText();
+        NextObjective nextObjective;
+
+        switch (opStr) {
+            case "ADD":
+                nextObjective = builder.add();
+                break;
+            case "REMOVE":
+                nextObjective = builder.remove();
+                break;
+            default:
+                log.warn(INVALID_OP_MESSAGE, opStr);
+                return null;
+        }
+
+        return nextObjective;
+    }
+}
diff --git a/core/common/src/main/java/org/onosproject/codec/impl/ObjectiveCodecHelper.java b/core/common/src/main/java/org/onosproject/codec/impl/ObjectiveCodecHelper.java
new file mode 100644
index 0000000..4434ae0
--- /dev/null
+++ b/core/common/src/main/java/org/onosproject/codec/impl/ObjectiveCodecHelper.java
@@ -0,0 +1,88 @@
+/*
+ * Copyright 2016 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.codec.impl;
+
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import org.onosproject.codec.CodecContext;
+import org.onosproject.net.flowobjective.Objective;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Objective Codec Helper.
+ */
+public class ObjectiveCodecHelper {
+
+    // JSON field names
+    private static final String ID = "id";
+    private static final String APP_ID = "appId";
+    private static final String OPERATION = "operation";
+    private static final String PERMANENT = "isPermanent";
+    private static final String PRIORITY = "priority";
+    private static final String TIMEOUT = "timeout";
+    public static final String REST_APP_ID = "org.onosproject.rest";
+
+    public ObjectNode encode(Objective objective, CodecContext context) {
+        checkNotNull(objective, "Objective cannot be null");
+
+        ObjectNode result = context.mapper().createObjectNode()
+                .put(ID, objective.id())
+                .put(OPERATION, objective.op().toString())
+                .put(PERMANENT, String.valueOf(objective.permanent()))
+                .put(PRIORITY, objective.priority())
+                .put(TIMEOUT, objective.timeout());
+
+        if (objective.appId() != null) {
+            result.put(APP_ID, objective.appId().toString());
+        }
+
+        return result;
+    }
+
+    public Objective.Builder decode(ObjectNode json, Objective.Builder builder, CodecContext context) {
+        if (json == null || !json.isObject()) {
+            return null;
+        }
+
+        // permanent
+        boolean permanent = false;
+        if (json.get(PERMANENT) != null) {
+            permanent = json.get(PERMANENT).asBoolean();
+        }
+
+        // timeout
+        int timeoutInt = 0;
+        if (json.get(TIMEOUT) != null) {
+            timeoutInt = json.get(TIMEOUT).asInt();
+        }
+
+        // priority
+        int priorityInt = 0;
+        if (json.get(PRIORITY) != null) {
+            priorityInt = json.get(PRIORITY).asInt();
+        }
+
+        if (permanent) {
+            builder.makePermanent()
+                    .makeTemporary(timeoutInt)
+                    .withPriority(priorityInt);
+        } else {
+            builder.makeTemporary(timeoutInt)
+                    .withPriority(priorityInt);
+        }
+        return builder;
+    }
+}