[ONOS-3603] Implement REST API for Group query, insert, delete

* Implement decoding feature for GroupBucketCodec and GroupCodec
* Implement GroupsWebResource
* Add unit test for GroupBucketCodec and GroupCodec
* Add unit test for GroupsWebResource
* Add group insertion json example
* Add Swagger doc

Change-Id: Ie58cba2e1af996c7b8652a55d9ef0c27207beafc

@@ -17,7 +17,6 @@ package org.onosproject.codec.impl;
 
 import com.codahale.metrics.Metric;
 import com.google.common.collect.ImmutableSet;
-
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Deactivate;
@@ -35,11 +34,11 @@ import org.onosproject.net.HostLocation;
 import org.onosproject.net.Link;
 import org.onosproject.net.Path;
 import org.onosproject.net.Port;
+import org.onosproject.net.device.PortStatistics;
 import org.onosproject.net.driver.Driver;
 import org.onosproject.net.flow.FlowEntry;
 import org.onosproject.net.flow.FlowRule;
 import org.onosproject.net.flow.TableStatisticsEntry;
-import org.onosproject.net.device.PortStatistics;
 import org.onosproject.net.flow.TrafficSelector;
 import org.onosproject.net.flow.TrafficTreatment;
 import org.onosproject.net.flow.criteria.Criterion;

@@ -15,14 +15,18 @@
  */
 package org.onosproject.codec.impl;
 
+import com.fasterxml.jackson.databind.node.ObjectNode;
 import org.onosproject.codec.CodecContext;
 import org.onosproject.codec.JsonCodec;
+import org.onosproject.core.DefaultGroupId;
+import org.onosproject.core.GroupId;
+import org.onosproject.net.PortNumber;
 import org.onosproject.net.flow.TrafficTreatment;
+import org.onosproject.net.group.DefaultGroupBucket;
 import org.onosproject.net.group.GroupBucket;
 
-import com.fasterxml.jackson.databind.node.ObjectNode;
-
 import static com.google.common.base.Preconditions.checkNotNull;
+import static org.onlab.util.Tools.nullIsIllegal;
 
 /**
  * Group bucket JSON codec.
@@ -36,6 +40,8 @@ public class GroupBucketCodec extends JsonCodec<GroupBucket> {
     private static final String WATCH_GROUP = "watchGroup";
     private static final String PACKETS = "packets";
     private static final String BYTES = "bytes";
+    private static final String MISSING_MEMBER_MESSAGE =
+            " member is required in Group";
 
     @Override
     public ObjectNode encode(GroupBucket bucket, CodecContext context) {
@@ -61,4 +67,59 @@ public class GroupBucketCodec extends JsonCodec<GroupBucket> {
 
         return result;
     }
+
+    @Override
+    public GroupBucket decode(ObjectNode json, CodecContext context) {
+        if (json == null || !json.isObject()) {
+            return null;
+        }
+
+        // build traffic treatment
+        ObjectNode treatmentJson = get(json, TREATMENT);
+        TrafficTreatment trafficTreatment = null;
+        if (treatmentJson != null) {
+            JsonCodec<TrafficTreatment> treatmentCodec =
+                    context.codec(TrafficTreatment.class);
+            trafficTreatment = treatmentCodec.decode(treatmentJson, context);
+        }
+
+        // parse group type
+        String type = nullIsIllegal(json.get(TYPE), TYPE + MISSING_MEMBER_MESSAGE).asText();
+        GroupBucket groupBucket = null;
+
+        switch (type) {
+            case "SELECT":
+                // parse weight
+                int weightInt = nullIsIllegal(json.get(WEIGHT), WEIGHT + MISSING_MEMBER_MESSAGE).asInt();
+
+                groupBucket =
+                        DefaultGroupBucket.createSelectGroupBucket(trafficTreatment, (short) weightInt);
+                break;
+            case "INDIRECT":
+                groupBucket =
+                        DefaultGroupBucket.createIndirectGroupBucket(trafficTreatment);
+                break;
+            case "ALL":
+                groupBucket =
+                        DefaultGroupBucket.createAllGroupBucket(trafficTreatment);
+                break;
+            case "FAILOVER":
+                // parse watchPort
+                PortNumber watchPort = PortNumber.portNumber(nullIsIllegal(json.get(WATCH_PORT),
+                        WATCH_PORT + MISSING_MEMBER_MESSAGE).asText());
+
+                // parse watchGroup
+                int groupIdInt = nullIsIllegal(json.get(WATCH_GROUP),
+                        WATCH_GROUP + MISSING_MEMBER_MESSAGE).asInt();
+                GroupId watchGroup = new DefaultGroupId((short) groupIdInt);
+
+                groupBucket =
+                        DefaultGroupBucket.createFailoverGroupBucket(trafficTreatment, watchPort, watchGroup);
+                break;
+            default:
+                DefaultGroupBucket.createAllGroupBucket(trafficTreatment);
+        }
+
+        return groupBucket;
+    }
 }

@@ -15,20 +15,40 @@
  */
 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.core.DefaultGroupId;
+import org.onosproject.core.GroupId;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.group.DefaultGroup;
+import org.onosproject.net.group.DefaultGroupDescription;
+import org.onosproject.net.group.DefaultGroupKey;
 import org.onosproject.net.group.Group;
 import org.onosproject.net.group.GroupBucket;
+import org.onosproject.net.group.GroupBuckets;
+import org.onosproject.net.group.GroupDescription;
+import org.onosproject.net.group.GroupKey;
+import org.slf4j.Logger;
 
-import com.fasterxml.jackson.databind.node.ArrayNode;
-import com.fasterxml.jackson.databind.node.ObjectNode;
+import java.util.ArrayList;
+import java.util.List;
+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;
 
 /**
  * Group JSON codec.
  */
 public final class GroupCodec extends JsonCodec<Group> {
+    private final Logger log = getLogger(getClass());
+
     // JSON field names
     private static final String ID = "id";
     private static final String STATE = "state";
@@ -37,11 +57,15 @@ public final class GroupCodec extends JsonCodec<Group> {
     private static final String BYTES = "bytes";
     private static final String REFERENCE_COUNT = "referenceCount";
     private static final String TYPE = "type";
+    private static final String GROUP_ID = "groupId";
     private static final String DEVICE_ID = "deviceId";
     private static final String APP_ID = "appId";
-    private static final String APP_COOKIE  = "appCookie";
-    private static final String GIVEN_GROUP_ID  = "givenGroupId";
+    private static final String APP_COOKIE = "appCookie";
+    private static final String GIVEN_GROUP_ID = "givenGroupId";
     private static final String BUCKETS = "buckets";
+    private static final String MISSING_MEMBER_MESSAGE =
+            " member is required in Group";
+    public static final String REST_APP_ID = "org.onosproject.rest";
 
     @Override
     public ObjectNode encode(Group group, CodecContext context) {
@@ -70,10 +94,81 @@ public final class GroupCodec extends JsonCodec<Group> {
 
         ArrayNode buckets = context.mapper().createArrayNode();
         group.buckets().buckets().forEach(bucket -> {
-                    ObjectNode bucketJson = context.codec(GroupBucket.class).encode(bucket, context);
-                    buckets.add(bucketJson);
-                });
+            ObjectNode bucketJson = context.codec(GroupBucket.class).encode(bucket, context);
+            buckets.add(bucketJson);
+        });
         result.set(BUCKETS, buckets);
         return result;
     }
+
+    @Override
+    public Group decode(ObjectNode json, CodecContext context) {
+        if (json == null || !json.isObject()) {
+            return null;
+        }
+
+        final JsonCodec<GroupBucket> groupBucketCodec = context.codec(GroupBucket.class);
+        CoreService coreService = context.getService(CoreService.class);
+
+        // parse group id
+        int groupIdInt = nullIsIllegal(json.get(GROUP_ID),
+                GROUP_ID + MISSING_MEMBER_MESSAGE).asInt();
+        GroupId groupId = new DefaultGroupId((short) groupIdInt);
+
+        // parse group key (appCookie)
+        String groupKeyStr = nullIsIllegal(json.get(APP_COOKIE),
+                APP_COOKIE + MISSING_MEMBER_MESSAGE).asText();
+        GroupKey groupKey = new DefaultGroupKey(groupKeyStr.getBytes());
+
+        // parse device id
+        DeviceId deviceId = DeviceId.deviceId(nullIsIllegal(json.get(DEVICE_ID),
+                DEVICE_ID + MISSING_MEMBER_MESSAGE).asText());
+
+        // application id
+        ApplicationId appId = coreService.registerApplication(REST_APP_ID);
+
+        // parse group type
+        String type = nullIsIllegal(json.get(TYPE),
+                TYPE + MISSING_MEMBER_MESSAGE).asText();
+        GroupDescription.Type groupType = null;
+
+        switch (type) {
+            case "SELECT":
+                groupType = Group.Type.SELECT;
+                break;
+            case "INDIRECT":
+                groupType = Group.Type.INDIRECT;
+                break;
+            case "ALL":
+                groupType = Group.Type.ALL;
+                break;
+            case "FAILOVER":
+                groupType = Group.Type.FAILOVER;
+                break;
+            default:
+                log.warn("The requested type {} is not defined for group.", type);
+                return null;
+        }
+
+        // parse group buckets
+        // TODO: make sure that INDIRECT group only has one bucket
+        GroupBuckets buckets = null;
+        List<GroupBucket> groupBucketList = new ArrayList<>();
+        JsonNode bucketsJson = json.get(BUCKETS);
+        checkNotNull(bucketsJson);
+        if (bucketsJson != null) {
+            IntStream.range(0, bucketsJson.size())
+                    .forEach(i -> {
+                        ObjectNode bucketJson = get(bucketsJson, i);
+                        bucketJson.put("type", type);
+                        groupBucketList.add(groupBucketCodec.decode(bucketJson, context));
+                    });
+            buckets = new GroupBuckets(groupBucketList);
+        }
+
+        GroupDescription groupDescription = new DefaultGroupDescription(deviceId,
+                groupType, buckets, groupKey, groupIdInt, appId);
+
+        return new DefaultGroup(groupId, groupDescription);
+    }
 }

@@ -15,21 +15,37 @@
  */
 package org.onosproject.codec.impl;
 
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import com.google.common.collect.ImmutableList;
+import org.junit.Before;
 import org.junit.Test;
+import org.onosproject.codec.JsonCodec;
+import org.onosproject.core.CoreService;
 import org.onosproject.core.DefaultGroupId;
 import org.onosproject.net.NetTestTools;
+import org.onosproject.net.PortNumber;
 import org.onosproject.net.flow.DefaultTrafficTreatment;
+import org.onosproject.net.flow.instructions.Instruction;
+import org.onosproject.net.flow.instructions.Instructions;
 import org.onosproject.net.group.DefaultGroup;
 import org.onosproject.net.group.DefaultGroupBucket;
+import org.onosproject.net.group.Group;
 import org.onosproject.net.group.GroupBucket;
 import org.onosproject.net.group.GroupBuckets;
 import org.onosproject.net.group.GroupDescription;
 
-import com.fasterxml.jackson.databind.node.ObjectNode;
-import com.google.common.collect.ImmutableList;
+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.GroupJsonMatcher.matchesGroup;
+import static org.onosproject.net.NetTestTools.APP_ID;
 
 /**
  * Group codec unit tests.
@@ -37,8 +53,28 @@ import static org.onosproject.codec.impl.GroupJsonMatcher.matchesGroup;
 
 public class GroupCodecTest {
 
+    MockCodecContext context;
+    JsonCodec<Group> groupCodec;
+    final CoreService mockCoreService = createMock(CoreService.class);
+
+    /**
+     * Sets up for each test.  Creates a context and fetches the flow rule
+     * codec.
+     */
+    @Before
+    public void setUp() {
+        context = new MockCodecContext();
+        groupCodec = context.codec(Group.class);
+        assertThat(groupCodec, notNullValue());
+
+        expect(mockCoreService.registerApplication(GroupCodec.REST_APP_ID))
+                .andReturn(APP_ID).anyTimes();
+        replay(mockCoreService);
+        context.registerService(CoreService.class, mockCoreService);
+    }
+
     @Test
-    public void codecTest() {
+    public void codecEncodeTest() {
         GroupBucket bucket1 = DefaultGroupBucket
                 .createSelectGroupBucket(DefaultTrafficTreatment.emptyTreatment());
         GroupBucket bucket2 = DefaultGroupBucket
@@ -58,4 +94,48 @@ public class GroupCodecTest {
 
         assertThat(groupJson, matchesGroup(group));
     }
+
+    @Test
+    public void codecDecodeTest() throws IOException {
+        Group group = getGroup("simple-group.json");
+        checkCommonData(group);
+
+        assertThat(group.buckets().buckets().size(), is(1));
+        GroupBucket groupBucket = group.buckets().buckets().get(0);
+        assertThat(groupBucket.type().toString(), is("ALL"));
+        assertThat(groupBucket.treatment().allInstructions().size(), is(1));
+        Instruction instruction1 = groupBucket.treatment().allInstructions().get(0);
+        assertThat(instruction1.type(), is(Instruction.Type.OUTPUT));
+        assertThat(((Instructions.OutputInstruction) instruction1).port(), is(PortNumber.portNumber(2)));
+    }
+
+    /**
+     * Checks that the data shared by all the resource is correct for a given group.
+     *
+     * @param group group to check
+     */
+    private void checkCommonData(Group group) {
+        assertThat(group.appId(), is(APP_ID));
+        assertThat(group.deviceId().toString(), is("of:0000000000000001"));
+        assertThat(group.type().toString(), is("ALL"));
+        assertThat(group.appCookie().key(), is("1".getBytes()));
+        assertThat(group.id().id(), is(1));
+    }
+
+    /**
+     * Reads in a group from the given resource and decodes it.
+     *
+     * @param resourceName resource to use to read the JSON for the rule
+     * @return decoded group
+     * @throws IOException if processing the resource fails
+     */
+    private Group getGroup(String resourceName) throws IOException {
+        InputStream jsonStream = GroupCodecTest.class
+                .getResourceAsStream(resourceName);
+        JsonNode json = context.mapper().readTree(jsonStream);
+        assertThat(json, notNullValue());
+        Group group = groupCodec.decode((ObjectNode) json, context);
+        assertThat(group, notNullValue());
+        return group;
+    }
 }

+{
+  "type": "ALL",
+  "deviceId": "of:0000000000000001",
+  "appCookie": "1",
+  "groupId": "1",
+  "buckets": [
+    {
+      "treatment": {
+        "instructions": [
+          {
+            "type": "OUTPUT",
+            "port": 2
+          }
+        ]
+      }
+    }
+  ]
+}
\ No newline at end of file

@@ -37,6 +37,7 @@ public class CoreWebApplication extends AbstractWebApplication {
                           HostsWebResource.class,
                           IntentsWebResource.class,
                           FlowsWebResource.class,
+                          GroupsWebResource.class,
                           TopologyWebResource.class,
                           ConfigWebResource.class,
                           PathsWebResource.class,

+/*
+ * Copyright 2014-2015 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.rest.resources;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import org.onosproject.net.Device;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.device.DeviceService;
+import org.onosproject.net.group.DefaultGroupDescription;
+import org.onosproject.net.group.DefaultGroupKey;
+import org.onosproject.net.group.Group;
+import org.onosproject.net.group.GroupDescription;
+import org.onosproject.net.group.GroupKey;
+import org.onosproject.net.group.GroupService;
+import org.onosproject.rest.AbstractWebResource;
+
+import javax.ws.rs.Consumes;
+import javax.ws.rs.DELETE;
+import javax.ws.rs.GET;
+import javax.ws.rs.POST;
+import javax.ws.rs.Path;
+import javax.ws.rs.PathParam;
+import javax.ws.rs.Produces;
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URI;
+import java.net.URISyntaxException;
+
+/**
+ * Query and program group rules.
+ */
+
+@Path("groups")
+public class GroupsWebResource extends AbstractWebResource {
+    public static final String DEVICE_INVALID = "Invalid deviceId in group creation request";
+
+    final GroupService groupService = get(GroupService.class);
+    final ObjectNode root = mapper().createObjectNode();
+    final ArrayNode groupsNode = root.putArray("groups");
+
+    /**
+     * Returns all groups of all devices.
+     * @onos.rsModel Groups
+     * @return array of all the groups in the system
+     */
+    @GET
+    @Produces(MediaType.APPLICATION_JSON)
+    public Response getGroups() {
+        final Iterable<Device> devices = get(DeviceService.class).getDevices();
+        devices.forEach(device -> {
+            final Iterable<Group> groups = groupService.getGroups(device.id());
+            if (groups != null) {
+                groups.forEach(group -> groupsNode.add(codec(Group.class).encode(group, this)));
+            }
+        });
+
+        return ok(root).build();
+    }
+
+    /**
+     * Returns all groups associated with the given device.
+     *
+     * @param deviceId device identifier
+     * @onos.rsModel Groups
+     * @return array of all the groups in the system
+     */
+    @GET
+    @Produces(MediaType.APPLICATION_JSON)
+    @Path("{deviceId}")
+    public Response getGroupsByDeviceId(@PathParam("deviceId") String deviceId) {
+        final Iterable<Group> groups = groupService.getGroups(DeviceId.deviceId(deviceId));
+
+        groups.forEach(group -> groupsNode.add(codec(Group.class).encode(group, this)));
+
+        return ok(root).build();
+    }
+
+    /**
+     * Create new group rule. Creates and installs a new group rule for the
+     * specified device.
+     *
+     * @param deviceId device identifier
+     * @param stream   group rule JSON
+     * @onos.rsModel GroupsPost
+     * @return status of the request - CREATED if the JSON is correct,
+     * BAD_REQUEST if the JSON is invalid
+     */
+    @POST
+    @Path("{deviceId}")
+    @Consumes(MediaType.APPLICATION_JSON)
+    @Produces(MediaType.APPLICATION_JSON)
+    public Response createGroup(@PathParam("deviceId") String deviceId,
+                                InputStream stream) {
+        URI location;
+        try {
+            ObjectNode jsonTree = (ObjectNode) mapper().readTree(stream);
+            JsonNode specifiedDeviceId = jsonTree.get("deviceId");
+
+            if (specifiedDeviceId != null &&
+                    !specifiedDeviceId.asText().equals(deviceId)) {
+                throw new IllegalArgumentException(DEVICE_INVALID);
+            }
+            jsonTree.put("deviceId", deviceId);
+            Group group = codec(Group.class).decode(jsonTree, this);
+            GroupDescription description = new DefaultGroupDescription(
+                    group.deviceId(), group.type(), group.buckets(),
+                    group.appCookie(), group.id().id(), group.appId());
+            groupService.addGroup(description);
+            location = new URI(Long.toString(group.id().id()));
+        } catch (IOException | URISyntaxException ex) {
+            throw new IllegalArgumentException(ex);
+        }
+
+        return Response
+                .created(location)
+                .build();
+    }
+
+    /**
+     * Removes the specified group.
+     *
+     * @param deviceId  device identifier
+     * @param appCookie application cookie to be used for lookup
+     */
+    @DELETE
+    @Produces(MediaType.APPLICATION_JSON)
+    @Path("{deviceId}/{appCookie}")
+    public void deleteGroupByDeviceIdAndAppCookie(@PathParam("deviceId") String deviceId,
+                                                  @PathParam("appCookie") String appCookie) {
+        DeviceId deviceIdInstance = DeviceId.deviceId(deviceId);
+        GroupKey appCookieInstance = new DefaultGroupKey(appCookie.getBytes());
+
+        groupService.removeGroup(deviceIdInstance, appCookieInstance, null);
+    }
+}

+{
+  "type": "object",
+  "title": "groups",
+  "required": [
+    "groups"
+  ],
+  "properties": {
+    "groups": {
+      "type": "array",
+      "xml": {
+        "name": "groups",
+        "wrapped": true
+      },
+      "items": {
+        "type": "object",
+        "title": "group",
+        "required": [
+          "id",
+          "state",
+          "life",
+          "packets",
+          "bytes",
+          "referenceCount",
+          "type",
+          "deviceId",
+          "buckets"
+        ],
+        "properties": {
+          "id": {
+            "type": "string",
+            "example": "1"
+          },
+          "state": {
+            "type": "string",
+            "example": "PENDING_ADD"
+          },
+          "life": {
+            "type": "integer",
+            "format": "int64",
+            "example": 69889
+          },
+          "packets": {
+            "type": "integer",
+            "format": "int64",
+            "example": 22546
+          },
+          "bytes": {
+            "type": "integer",
+            "format": "int64",
+            "example": 1826226
+          },
+          "referenceCount": {
+            "type": "integer",
+            "format": "int64",
+            "example": 1826226
+          },
+          "type": {
+            "type": "string",
+            "example": "ALL"
+          },
+          "deviceId": {
+            "type": "string",
+            "example": "of:0000000000000003"
+          },
+          "buckets": {
+            "type": "array",
+            "xml": {
+              "name": "buckets",
+              "wrapped": true
+            },
+            "items": {
+              "type": "object",
+              "title": "buckets",
+              "required": [
+                "treatment",
+                "weight",
+                "watchPort",
+                "watchGroup"
+              ],
+              "properties": {
+                "treatment": {
+                  "type": "object",
+                  "title": "treatment",
+                  "required": [
+                    "instructions",
+                    "deferred"
+                  ],
+                  "properties": {
+                    "instructions": {
+                      "type": "array",
+                      "title": "treatment",
+                      "required": [
+                        "properties",
+                        "port"
+                      ],
+                      "items": {
+                        "type": "object",
+                        "title": "instructions",
+                        "required": [
+                          "type",
+                          "port"
+                        ],
+                        "properties": {
+                          "type": {
+                            "type": "string",
+                            "example": "OUTPUT"
+                          },
+                          "port": {
+                            "type": "string",
+                            "example": "2"
+                          }
+                        }
+                      }
+                    }
+                  }
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+}
\ No newline at end of file

+{
+  "type": "object",
+  "title": "group",
+  "required": [
+    "type",
+    "deviceId",
+    "appCookie",
+    "groupId",
+    "buckets"
+  ],
+  "properties": {
+    "type": {
+      "type": "string",
+      "example": "ALL"
+    },
+    "deviceId": {
+      "type": "string",
+      "example": "of:0000000000000001"
+    },
+    "appCookie": {
+      "type": "string",
+      "example": "1"
+    },
+    "groupId": {
+      "type": "string",
+      "example": "1"
+    },
+    "buckets": {
+      "type": "array",
+      "xml": {
+        "name": "buckets",
+        "wrapped": true
+      },
+      "items": {
+        "type": "object",
+        "title": "buckets",
+        "required": [
+          "treatment",
+          "weight",
+          "watchPort",
+          "watchGroup"
+        ],
+        "properties": {
+          "treatment": {
+            "type": "object",
+            "title": "treatment",
+            "required": [
+              "instructions",
+              "deferred"
+            ],
+            "properties": {
+              "instructions": {
+                "type": "array",
+                "title": "treatment",
+                "required": [
+                  "properties",
+                  "port"
+                ],
+                "items": {
+                  "type": "object",
+                  "title": "instructions",
+                  "required": [
+                    "type",
+                    "port"
+                  ],
+                  "properties": {
+                    "type": {
+                      "type": "string",
+                      "example": "OUTPUT"
+                    },
+                    "port": {
+                      "type": "string",
+                      "example": "2"
+                    }
+                  }
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  }
+}
\ No newline at end of file

+/*
+ * Copyright 2014-2015 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.rest;
+
+import com.eclipsesource.json.JsonArray;
+import com.eclipsesource.json.JsonObject;
+import com.google.common.collect.ImmutableSet;
+import com.sun.jersey.api.client.ClientResponse;
+import com.sun.jersey.api.client.WebResource;
+import org.hamcrest.Description;
+import org.hamcrest.TypeSafeMatcher;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.onlab.osgi.ServiceDirectory;
+import org.onlab.osgi.TestServiceDirectory;
+import org.onlab.rest.BaseResource;
+import org.onosproject.codec.CodecService;
+import org.onosproject.codec.impl.CodecManager;
+import org.onosproject.codec.impl.GroupCodec;
+import org.onosproject.core.ApplicationId;
+import org.onosproject.core.CoreService;
+import org.onosproject.core.DefaultApplicationId;
+import org.onosproject.core.DefaultGroupId;
+import org.onosproject.core.GroupId;
+import org.onosproject.net.DefaultDevice;
+import org.onosproject.net.Device;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.NetTestTools;
+import org.onosproject.net.device.DeviceService;
+import org.onosproject.net.group.DefaultGroupKey;
+import org.onosproject.net.group.Group;
+import org.onosproject.net.group.GroupBucket;
+import org.onosproject.net.group.GroupBuckets;
+import org.onosproject.net.group.GroupDescription;
+import org.onosproject.net.group.GroupKey;
+import org.onosproject.net.group.GroupService;
+
+import javax.ws.rs.core.MediaType;
+import java.io.InputStream;
+import java.net.HttpURLConnection;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import static org.easymock.EasyMock.anyObject;
+import static org.easymock.EasyMock.anyShort;
+import static org.easymock.EasyMock.createMock;
+import static org.easymock.EasyMock.expect;
+import static org.easymock.EasyMock.expectLastCall;
+import static org.easymock.EasyMock.replay;
+import static org.easymock.EasyMock.verify;
+import static org.hamcrest.Matchers.hasSize;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.notNullValue;
+import static org.junit.Assert.assertThat;
+import static org.onosproject.net.NetTestTools.APP_ID;
+
+/**
+ * Unit tests for Groups REST APIs.
+ */
+public class GroupsResourceTest extends ResourceTest {
+    final GroupService mockGroupService = createMock(GroupService.class);
+    CoreService mockCoreService = createMock(CoreService.class);
+    final DeviceService mockDeviceService = createMock(DeviceService.class);
+
+    final HashMap<DeviceId, Set<Group>> groups = new HashMap<>();
+
+
+    final DeviceId deviceId1 = DeviceId.deviceId("1");
+    final DeviceId deviceId2 = DeviceId.deviceId("2");
+    final DeviceId deviceId3 = DeviceId.deviceId("3");
+    final Device device1 = new DefaultDevice(null, deviceId1, Device.Type.OTHER,
+            "", "", "", "", null);
+    final Device device2 = new DefaultDevice(null, deviceId2, Device.Type.OTHER,
+            "", "", "", "", null);
+
+    final MockGroup group1 = new MockGroup(deviceId1, 1, "111", 1);
+    final MockGroup group2 = new MockGroup(deviceId1, 2, "222", 2);
+
+    final MockGroup group3 = new MockGroup(deviceId2, 3, "333", 3);
+    final MockGroup group4 = new MockGroup(deviceId2, 4, "444", 4);
+
+    final MockGroup group5 = new MockGroup(deviceId3, 5, "555", 5);
+    final MockGroup group6 = new MockGroup(deviceId3, 6, "666", 6);
+
+    /**
+     * Mock class for a group.
+     */
+    private static class MockGroup implements Group {
+
+        final DeviceId deviceId;
+        final ApplicationId appId;
+        final GroupKey appCookie;
+        final long baseValue;
+        final List<GroupBucket> bucketList;
+        GroupBuckets buckets;
+
+        public MockGroup(DeviceId deviceId, int appId, String appCookie, int id) {
+            this.deviceId = deviceId;
+            this.appId = new DefaultApplicationId(appId, String.valueOf(appId));
+            this.appCookie = new DefaultGroupKey(appCookie.getBytes());
+            this.baseValue = id * 100;
+            this.bucketList = new ArrayList<>();
+            this.buckets = new GroupBuckets(bucketList);
+        }
+
+        @Override
+        public GroupId id() {
+            return new DefaultGroupId((int) baseValue + 55);
+        }
+
+        @Override
+        public GroupState state() {
+            return GroupState.ADDED;
+        }
+
+        @Override
+        public long life() {
+            return baseValue + 11;
+        }
+
+        @Override
+        public long packets() {
+            return baseValue + 22;
+        }
+
+        @Override
+        public long bytes() {
+            return baseValue + 33;
+        }
+
+        @Override
+        public long referenceCount() {
+            return baseValue + 44;
+        }
+
+        @Override
+        public Type type() {
+            return GroupDescription.Type.ALL;
+        }
+
+        @Override
+        public DeviceId deviceId() {
+            return this.deviceId;
+        }
+
+        @Override
+        public ApplicationId appId() {
+            return this.appId;
+        }
+
+        @Override
+        public GroupKey appCookie() {
+            return this.appCookie;
+        }
+
+        @Override
+        public Integer givenGroupId() {
+            return (int) baseValue + 55;
+        }
+
+        @Override
+        public GroupBuckets buckets() {
+            return this.buckets;
+        }
+    }
+
+    /**
+     * Populates some groups used as testing data.
+     */
+    private void setupMockGroups() {
+        final Set<Group> groups1 = new HashSet<>();
+        groups1.add(group1);
+        groups1.add(group2);
+
+        final Set<Group> groups2 = new HashSet<>();
+        groups2.add(group3);
+        groups2.add(group4);
+
+        groups.put(deviceId1, groups1);
+        groups.put(deviceId2, groups2);
+
+        expect(mockGroupService.getGroups(deviceId1))
+                .andReturn(groups.get(deviceId1)).anyTimes();
+        expect(mockGroupService.getGroups(deviceId2))
+                .andReturn(groups.get(deviceId2)).anyTimes();
+    }
+
+    /**
+     * Sets up the global values for all the tests.
+     */
+    @Before
+    public void setUpTest() {
+        // Mock device service
+        expect(mockDeviceService.getDevice(deviceId1))
+                .andReturn(device1);
+        expect(mockDeviceService.getDevice(deviceId2))
+                .andReturn(device2);
+        expect(mockDeviceService.getDevices())
+                .andReturn(ImmutableSet.of(device1, device2));
+
+        // Mock Core Service
+        expect(mockCoreService.getAppId(anyShort()))
+                .andReturn(NetTestTools.APP_ID).anyTimes();
+        expect(mockCoreService.registerApplication(GroupCodec.REST_APP_ID))
+                .andReturn(APP_ID).anyTimes();
+        replay(mockCoreService);
+
+        // Register the services needed for the test
+        final CodecManager codecService = new CodecManager();
+        codecService.activate();
+        ServiceDirectory testDirectory =
+                new TestServiceDirectory()
+                        .add(GroupService.class, mockGroupService)
+                        .add(DeviceService.class, mockDeviceService)
+                        .add(CodecService.class, codecService)
+                        .add(CoreService.class, mockCoreService);
+
+        BaseResource.setServiceDirectory(testDirectory);
+    }
+
+    /**
+     * Cleans up and verifies the mocks.
+     */
+    @After
+    public void tearDownTest() {
+        verify(mockGroupService);
+        verify(mockCoreService);
+    }
+
+    /**
+     * Hamcrest matcher to check that a group representation in JSON matches
+     * the actual group.
+     */
+    public static class GroupJsonMatcher extends TypeSafeMatcher<JsonObject> {
+        private final Group group;
+        private final String expectedAppId;
+        private String reason = "";
+
+        public GroupJsonMatcher(Group groupValue, String expectedAppIdValue) {
+            group = groupValue;
+            expectedAppId = expectedAppIdValue;
+        }
+
+        @Override
+        public boolean matchesSafely(JsonObject jsonGroup) {
+            // check id
+            final String jsonId = jsonGroup.get("id").asString();
+            final String groupId = group.id().toString();
+            if (!jsonId.equals(groupId)) {
+                reason = "id " + group.id().toString();
+                return false;
+            }
+
+            // check application id
+            final String jsonAppId = jsonGroup.get("appId").asString();
+            final String appId = group.appId().toString();
+            if (!jsonAppId.equals(appId)) {
+                reason = "appId " + group.appId().toString();
+                return false;
+            }
+
+            // check device id
+            final String jsonDeviceId = jsonGroup.get("deviceId").asString();
+            if (!jsonDeviceId.equals(group.deviceId().toString())) {
+                reason = "deviceId " + group.deviceId();
+                return false;
+            }
+
+            // check bucket array
+            if (group.buckets().buckets() != null) {
+                final JsonArray jsonBuckets = jsonGroup.get("buckets").asArray();
+                if (group.buckets().buckets().size() != jsonBuckets.size()) {
+                    reason = "buckets array size of " +
+                            Integer.toString(group.buckets().buckets().size());
+                    return false;
+                }
+                for (final GroupBucket groupBucket : group.buckets().buckets()) {
+                    boolean groupBucketFound = false;
+                    for (int groupBucketIndex = 0; groupBucketIndex < jsonBuckets.size(); groupBucketIndex++) {
+                        final String jsonType = jsonBuckets.get(groupBucketIndex).asObject().get("type").asString();
+                        final String bucketType = groupBucket.type().name();
+                        if (jsonType.equals(bucketType)) {
+                            groupBucketFound = true;
+                        }
+                    }
+                    if (!groupBucketFound) {
+                        reason = "group bucket " + groupBucket.toString();
+                        return false;
+                    }
+                }
+            }
+
+            return true;
+        }
+
+        @Override
+        public void describeTo(Description description) {
+            description.appendText(reason);
+        }
+    }
+
+    /**
+     * Factory to allocate a group matcher.
+     *
+     * @param group group object we are looking for
+     * @return matcher
+     */
+    private static GroupJsonMatcher matchesGroup(Group group, String expectedAppName) {
+        return new GroupJsonMatcher(group, expectedAppName);
+    }
+
+    /**
+     * Hamcrest matcher to check that a group is represented properly in a JSON
+     * array of flows.
+     */
+    public static class GroupJsonArrayMatcher extends TypeSafeMatcher<JsonArray> {
+        private final Group group;
+        private String reason = "";
+
+        public GroupJsonArrayMatcher(Group groupValue) {
+            group = groupValue;
+        }
+
+        @Override
+        public boolean matchesSafely(JsonArray json) {
+            boolean groupFound = false;
+            for (int jsonGroupIndex = 0; jsonGroupIndex < json.size();
+                 jsonGroupIndex++) {
+
+                final JsonObject jsonGroup = json.get(jsonGroupIndex).asObject();
+
+                final String groupId = group.id().toString();
+                final String jsonGroupId = jsonGroup.get("id").asString();
+                if (jsonGroupId.equals(groupId)) {
+                    groupFound = true;
+
+                    //  We found the correct group, check attribute values
+                    assertThat(jsonGroup, matchesGroup(group, APP_ID.name()));
+                }
+            }
+            if (!groupFound) {
+                reason = "Group with id " + group.id().toString() + " not found";
+                return false;
+            } else {
+                return true;
+            }
+        }
+
+        @Override
+        public void describeTo(Description description) {
+            description.appendText(reason);
+        }
+    }
+
+    /**
+     * Factory to allocate a group array matcher.
+     *
+     * @param group group object we are looking for
+     * @return matcher
+     */
+    private static GroupJsonArrayMatcher hasGroup(Group group) {
+        return new GroupJsonArrayMatcher(group);
+    }
+
+    /**
+     * Tests the result of the rest api GET when there are no groups.
+     */
+    @Test
+    public void testGroupsEmptyArray() {
+        expect(mockGroupService.getGroups(deviceId1)).andReturn(null).anyTimes();
+        expect(mockGroupService.getGroups(deviceId2)).andReturn(null).anyTimes();
+        replay(mockGroupService);
+        replay(mockDeviceService);
+        final WebResource rs = resource();
+        final String response = rs.path("groups").get(String.class);
+        assertThat(response, is("{\"groups\":[]}"));
+    }
+
+    /**
+     * Tests the result of the rest api GET when there are active groups.
+     */
+    @Test
+    public void testGroupsPopulatedArray() {
+        setupMockGroups();
+        replay(mockGroupService);
+        replay(mockDeviceService);
+        final WebResource rs = resource();
+        final String response = rs.path("groups").get(String.class);
+        final JsonObject result = JsonObject.readFrom(response);
+        assertThat(result, notNullValue());
+
+        assertThat(result.names(), hasSize(1));
+        assertThat(result.names().get(0), is("groups"));
+        final JsonArray jsonGroups = result.get("groups").asArray();
+        assertThat(jsonGroups, notNullValue());
+        assertThat(jsonGroups, hasGroup(group1));
+        assertThat(jsonGroups, hasGroup(group2));
+        assertThat(jsonGroups, hasGroup(group3));
+        assertThat(jsonGroups, hasGroup(group4));
+    }
+
+    /**
+     * Tests the result of a rest api GET for a device.
+     */
+    @Test
+    public void testGroupsSingleDevice() {
+        setupMockGroups();
+        final Set<Group> groups = new HashSet<>();
+        groups.add(group5);
+        groups.add(group6);
+        expect(mockGroupService.getGroups(anyObject()))
+                .andReturn(groups).anyTimes();
+        replay(mockGroupService);
+        replay(mockDeviceService);
+        final WebResource rs = resource();
+        final String response = rs.path("groups/" + deviceId3).get(String.class);
+        final JsonObject result = JsonObject.readFrom(response);
+        assertThat(result, notNullValue());
+
+        assertThat(result.names(), hasSize(1));
+        assertThat(result.names().get(0), is("groups"));
+        final JsonArray jsonFlows = result.get("groups").asArray();
+        assertThat(jsonFlows, notNullValue());
+        assertThat(jsonFlows, hasGroup(group5));
+        assertThat(jsonFlows, hasGroup(group6));
+    }
+
+    /**
+     * Tests creating a group with POST.
+     */
+    @Test
+    public void testPost() {
+        mockGroupService.addGroup(anyObject());
+        expectLastCall();
+        replay(mockGroupService);
+
+        WebResource rs = resource();
+        InputStream jsonStream = GroupsResourceTest.class
+                .getResourceAsStream("post-group.json");
+
+        ClientResponse response = rs.path("groups/of:0000000000000001")
+                .type(MediaType.APPLICATION_JSON_TYPE)
+                .post(ClientResponse.class, jsonStream);
+        assertThat(response.getStatus(), is(HttpURLConnection.HTTP_CREATED));
+    }
+
+    /**
+     * Tests deleting a group.
+     */
+    @Test
+    public void testDelete() {
+        setupMockGroups();
+        mockGroupService.removeGroup(anyObject(), anyObject(), anyObject());
+        expectLastCall();
+        replay(mockGroupService);
+
+        WebResource rs = resource();
+
+        String location = "/groups/1/111";
+
+        ClientResponse deleteResponse = rs.path(location)
+                .type(MediaType.APPLICATION_JSON_TYPE)
+                .delete(ClientResponse.class);
+        assertThat(deleteResponse.getStatus(),
+                is(HttpURLConnection.HTTP_NO_CONTENT));
+    }
+}

+{
+  "type": "ALL",
+  "deviceId": "of:0000000000000001",
+  "appCookie": "1",
+  "groupId": "1",
+  "buckets": [
+    {
+      "treatment": {
+        "instructions": [
+          {
+            "type": "OUTPUT",
+            "port": 2
+          }
+        ]
+      }
+    }
+  ]
+}
\ No newline at end of file