[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/test/java/org/onosproject/codec/impl/NextObjectiveCodecTest.java b/core/common/src/test/java/org/onosproject/codec/impl/NextObjectiveCodecTest.java
new file mode 100644
index 0000000..06c6c9c
--- /dev/null
+++ b/core/common/src/test/java/org/onosproject/codec/impl/NextObjectiveCodecTest.java
@@ -0,0 +1,113 @@
+/*
+ * 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.junit.Before;
+import org.junit.Test;
+import org.onosproject.codec.JsonCodec;
+import org.onosproject.core.CoreService;
+import org.onosproject.net.flow.DefaultTrafficTreatment;
+import org.onosproject.net.flow.TrafficTreatment;
+import org.onosproject.net.flowobjective.DefaultNextObjective;
+import org.onosproject.net.flowobjective.NextObjective;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import static org.easymock.EasyMock.createMock;
+import static org.easymock.EasyMock.expect;
+import static org.easymock.EasyMock.replay;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.notNullValue;
+import static org.onosproject.codec.impl.NextObjectiveJsonMatcher.matchesNextObjective;
+import static org.onosproject.net.NetTestTools.APP_ID;
+
+/**
+ * Unit tests for NextObjective Codec.
+ */
+public class NextObjectiveCodecTest {
+
+    MockCodecContext context;
+    JsonCodec<NextObjective> nextObjectiveCodec;
+    final CoreService mockCoreService = createMock(CoreService.class);
+
+    /**
+     * Sets up for each test.
+     * Creates a context and fetches the NextObjective codec.
+     */
+    @Before
+    public void setUp() {
+        context = new MockCodecContext();
+        nextObjectiveCodec = context.codec(NextObjective.class);
+        assertThat(nextObjectiveCodec, notNullValue());
+
+        expect(mockCoreService.registerApplication(NextObjectiveCodec.REST_APP_ID))
+                .andReturn(APP_ID).anyTimes();
+        replay(mockCoreService);
+        context.registerService(CoreService.class, mockCoreService);
+    }
+
+    /**
+     * Tests encoding of a NextObjective object.
+     */
+    @Test
+    public void testNextObjectiveEncode() {
+
+        TrafficTreatment treatment = DefaultTrafficTreatment.builder().build();
+
+        NextObjective nextObj = DefaultNextObjective.builder()
+                .makePermanent()
+                .withType(NextObjective.Type.HASHED)
+                .fromApp(APP_ID)
+                .withPriority(60)
+                .withId(5)
+                .addTreatment(treatment)
+                .add();
+
+        ObjectNode nextObjJson = nextObjectiveCodec.encode(nextObj, context);
+        assertThat(nextObjJson, matchesNextObjective(nextObj));
+    }
+
+    /**
+     * Test decoding of a NextObjective object.
+     */
+    @Test
+    public void testNextObjectiveDecode() throws IOException {
+        NextObjective nextObjective = getNextObjective("NextObjective.json");
+
+        assertThat(nextObjective.type(), is(NextObjective.Type.FAILOVER));
+        assertThat(nextObjective.op(), is(NextObjective.Operation.ADD));
+    }
+
+    /**
+     * Reads in a nextObjective from the given resource and decodes it.
+     *
+     * @param resourceName resource to use to read the JSON for the rule
+     * @return decoded nextObjective
+     * @throws IOException if processing the resource fails
+     */
+    private NextObjective getNextObjective(String resourceName) throws IOException {
+        InputStream jsonStream = NextObjectiveCodecTest.class.getResourceAsStream(resourceName);
+        JsonNode json = context.mapper().readTree(jsonStream);
+        assertThat(json, notNullValue());
+        NextObjective nextObjective = nextObjectiveCodec.decode((ObjectNode) json, context);
+        assertThat(nextObjective, notNullValue());
+        return nextObjective;
+    }
+}