Implement REST APIs for flows:

- get all flows
- get all flows for a device
- get all flows for a device with a given ID

Change-Id: Ifb1541e4ae4a7e49f1347b34bef2fe788902368d

@@ -41,6 +41,7 @@
         <dependency>
             <groupId>org.easymock</groupId>
             <artifactId>easymock</artifactId>
+            <scope>test</scope>
         </dependency>
     </dependencies>
 

@@ -29,6 +29,9 @@ import org.onosproject.net.Host;
 import org.onosproject.net.HostLocation;
 import org.onosproject.net.Link;
 import org.onosproject.net.Port;
+import org.onosproject.net.flow.FlowEntry;
+import org.onosproject.net.flow.TrafficSelector;
+import org.onosproject.net.flow.TrafficTreatment;
 import org.onosproject.net.intent.Intent;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -59,6 +62,9 @@ public class CodecManager implements CodecService {
         registerCodec(Host.class, new HostCodec());
         registerCodec(HostLocation.class, new HostLocationCodec());
         registerCodec(Intent.class, new IntentCodec());
+        registerCodec(FlowEntry.class, new FlowEntryCodec());
+        registerCodec(TrafficTreatment.class, new TrafficTreatmentCodec());
+        registerCodec(TrafficSelector.class, new TrafficSelectorCodec());
         log.info("Started");
     }
 

+/*
+ * Copyright 2014 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 org.onosproject.codec.CodecContext;
+import org.onosproject.codec.JsonCodec;
+import org.onosproject.net.flow.FlowEntry;
+import org.onosproject.net.flow.TrafficSelector;
+import org.onosproject.net.flow.TrafficTreatment;
+
+import com.fasterxml.jackson.databind.node.ObjectNode;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Flow entry JSON codec.
+ */
+public class FlowEntryCodec extends JsonCodec<FlowEntry> {
+
+    @Override
+    public ObjectNode encode(FlowEntry flowEntry, CodecContext context) {
+        checkNotNull(flowEntry, "Flow entry cannot be null");
+
+        final ObjectNode result = context.mapper().createObjectNode()
+                .put("id", Long.toString(flowEntry.id().value()))
+                .put("appId", flowEntry.appId())
+                .put("groupId", flowEntry.groupId().id())
+                .put("priority", flowEntry.priority())
+                .put("timeout", flowEntry.timeout())
+                .put("isPermanent", flowEntry.isPermanent())
+                .put("deviceId", flowEntry.deviceId().toString())
+                .put("state", flowEntry.state().toString())
+                .put("life", flowEntry.life())
+                .put("packets", flowEntry.packets())
+                .put("bytes", flowEntry.bytes())
+                .put("lastSeen", flowEntry.lastSeen());
+
+        if (flowEntry.treatment() != null) {
+            final JsonCodec<TrafficTreatment> treatmentCodec =
+                    new TrafficTreatmentCodec();
+            result.set("treatment", treatmentCodec.encode(flowEntry.treatment(), context));
+        }
+
+        if (flowEntry.selector() != null) {
+            final JsonCodec<TrafficSelector> selectorCodec =
+                    new TrafficSelectorCodec();
+            result.set("selector", selectorCodec.encode(flowEntry.selector(), context));
+        }
+
+        return result;
+    }
+
+}
+

+/*
+ * Copyright 2014 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 org.onosproject.codec.CodecContext;
+import org.onosproject.codec.JsonCodec;
+import org.onosproject.net.flow.TrafficSelector;
+import org.onosproject.net.flow.criteria.Criterion;
+
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Traffic selector codec.
+ */
+public class TrafficSelectorCodec extends JsonCodec<TrafficSelector> {
+    @Override
+    public ObjectNode encode(TrafficSelector selector, CodecContext context) {
+        checkNotNull(selector, "Traffic selector cannot be null");
+
+        final ObjectNode result = context.mapper().createObjectNode();
+        final ArrayNode jsonCriteria = result.putArray("criteria");
+
+        if (selector.criteria() != null) {
+            for (final Criterion criterion :selector.criteria()) {
+                // TODO: would be better to have a codec that understands criteria
+                jsonCriteria.add(criterion.toString());
+            }
+        }
+
+        return result;
+    }
+}

+/*
+ * Copyright 2014 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 org.onosproject.codec.CodecContext;
+import org.onosproject.codec.JsonCodec;
+import org.onosproject.net.flow.TrafficTreatment;
+import org.onosproject.net.flow.instructions.Instruction;
+
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Traffic treatment codec.
+ */
+public class TrafficTreatmentCodec extends JsonCodec<TrafficTreatment> {
+    @Override
+    public ObjectNode encode(TrafficTreatment treatment, CodecContext context) {
+        checkNotNull(treatment, "Traffic treatment cannot be null");
+
+        final ObjectNode result = context.mapper().createObjectNode();
+        final ArrayNode jsonInstructions = result.putArray("instructions");
+
+        if (treatment.instructions() != null) {
+            for (final Instruction instruction : treatment.instructions()) {
+                // TODO: would be better to have a codec that understands instructions
+                jsonInstructions.add(instruction.toString());
+            }
+        }
+
+        return result;
+    }
+}

+/*
+ * Copyright 2014 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 javax.ws.rs.GET;
+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 org.onlab.util.ItemNotFoundException;
+import org.onosproject.codec.impl.FlowEntryCodec;
+import org.onosproject.net.Device;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.device.DeviceService;
+import org.onosproject.net.flow.FlowEntry;
+import org.onosproject.net.flow.FlowRuleService;
+
+import com.fasterxml.jackson.databind.node.ArrayNode;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+
+/**
+ * REST resource for interacting with the inventory of flows.
+ */
+
+@Path("flows")
+public class FlowsWebResource extends AbstractWebResource {
+    public static final String DEVICE_NOT_FOUND = "Device is not found";
+
+    final FlowRuleService service = get(FlowRuleService.class);
+    final ObjectNode root = mapper().createObjectNode();
+    final ArrayNode flowsNode = root.putArray("flows");
+    final FlowEntryCodec flowEntryCodec = new FlowEntryCodec();
+
+    /**
+     * Gets an array containing all the intents in the system.
+     *
+     * @return array of all the intents in the system
+     */
+    @GET
+    @Produces(MediaType.APPLICATION_JSON)
+    public Response getFlows() {
+
+        final Iterable<Device> devices = get(DeviceService.class).getDevices();
+        for (final Device device : devices) {
+            final Iterable<FlowEntry> deviceEntries = service.getFlowEntries(device.id());
+            if (deviceEntries != null) {
+                for (final FlowEntry entry : deviceEntries) {
+                    flowsNode.add(flowEntryCodec.encode(entry, this));
+                }
+            }
+        }
+
+        return ok(root.toString()).build();
+    }
+
+    /**
+     * Gets the flows for a device, where the device is specified by Id.
+     *
+     * @param deviceId Id of device to look up
+     * @return flow data as an array
+     */
+    @GET
+    @Produces(MediaType.APPLICATION_JSON)
+    @Path("{deviceId}")
+    public Response getFlowByDeviceId(@PathParam("deviceId") String deviceId) {
+        final Iterable<FlowEntry> deviceEntries =
+                service.getFlowEntries(DeviceId.deviceId(deviceId));
+
+        if (!deviceEntries.iterator().hasNext()) {
+            throw new ItemNotFoundException(DEVICE_NOT_FOUND);
+        }
+        for (final FlowEntry entry : deviceEntries) {
+            flowsNode.add(flowEntryCodec.encode(entry, this));
+        }
+        return ok(root.toString()).build();
+    }
+
+    /**
+     * Gets the flows for a device, where the device is specified by Id.
+     *
+     * @param deviceId Id of device to look up
+     * @param flowId Id of flow to look up
+     * @return flow data as an array
+     */
+    @GET
+    @Produces(MediaType.APPLICATION_JSON)
+    @Path("{deviceId}/{flowId}")
+    public Response getFlowByDeviceIdAndFlowId(@PathParam("deviceId") String deviceId,
+                                               @PathParam("flowId") long flowId) {
+        final Iterable<FlowEntry> deviceEntries =
+                service.getFlowEntries(DeviceId.deviceId(deviceId));
+
+        if (!deviceEntries.iterator().hasNext()) {
+            throw new ItemNotFoundException(DEVICE_NOT_FOUND);
+        }
+        for (final FlowEntry entry : deviceEntries) {
+            if (entry.id().value() == flowId) {
+                flowsNode.add(flowEntryCodec.encode(entry, this));
+            }
+        }
+        return ok(root.toString()).build();
+    }
+}

@@ -58,7 +58,7 @@ public class IntentsWebResource extends AbstractWebResource {
     @GET
     @Produces(MediaType.APPLICATION_JSON)
     @Path("{id}")
-    public Response getHostById(@PathParam("id") long id) {
+    public Response getIntentById(@PathParam("id") long id) {
         final Intent intent = nullIsNotFound(get(IntentService.class)
                         .getIntent(IntentId.valueOf(id)),
                 INTENT_NOT_FOUND);

@@ -39,6 +39,7 @@
                 org.onosproject.rest.LinksWebResource,
                 org.onosproject.rest.HostsWebResource,
                 org.onosproject.rest.IntentsWebResource,
+                org.onosproject.rest.FlowsWebResource,
                 org.onosproject.rest.ConfigResource
             </param-value>
         </init-param>

+/*
+ * Copyright 2014 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 java.util.HashMap;
+import java.util.HashSet;
+import java.util.Set;
+
+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.packet.MacAddress;
+import org.onlab.rest.BaseResource;
+import org.onosproject.codec.CodecService;
+import org.onosproject.codec.impl.CodecManager;
+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.device.DeviceService;
+import org.onosproject.net.flow.DefaultTrafficSelector;
+import org.onosproject.net.flow.DefaultTrafficTreatment;
+import org.onosproject.net.flow.FlowEntry;
+import org.onosproject.net.flow.FlowId;
+import org.onosproject.net.flow.FlowRuleService;
+import org.onosproject.net.flow.TrafficSelector;
+import org.onosproject.net.flow.TrafficTreatment;
+import org.onosproject.net.flow.criteria.Criterion;
+import org.onosproject.net.flow.instructions.Instruction;
+import org.onosproject.net.flow.instructions.L0ModificationInstruction;
+
+import com.eclipsesource.json.JsonArray;
+import com.eclipsesource.json.JsonObject;
+import com.eclipsesource.json.JsonValue;
+import com.google.common.collect.ImmutableSet;
+import com.sun.jersey.api.client.UniformInterfaceException;
+import com.sun.jersey.api.client.WebResource;
+import com.sun.jersey.test.framework.JerseyTest;
+
+import static org.easymock.EasyMock.anyObject;
+import static org.easymock.EasyMock.createMock;
+import static org.easymock.EasyMock.expect;
+import static org.easymock.EasyMock.replay;
+import static org.easymock.EasyMock.verify;
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.hasSize;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.not;
+import static org.hamcrest.Matchers.notNullValue;
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.fail;
+
+/**
+ * Unit tests for Flows REST APIs.
+ */
+public class FlowsResourceTest extends JerseyTest {
+    final FlowRuleService mockFlowService = createMock(FlowRuleService.class);
+    final HashMap<DeviceId, Set<FlowEntry>> rules = new HashMap<>();
+
+    final DeviceService mockDeviceService = createMock(DeviceService.class);
+
+    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 MockFlowEntry flow1 = new MockFlowEntry(deviceId1, 1);
+    final MockFlowEntry flow2 = new MockFlowEntry(deviceId1, 2);
+
+    final MockFlowEntry flow3 = new MockFlowEntry(deviceId2, 3);
+    final MockFlowEntry flow4 = new MockFlowEntry(deviceId2, 4);
+
+    final MockFlowEntry flow5 = new MockFlowEntry(deviceId2, 5);
+    final MockFlowEntry flow6 = new MockFlowEntry(deviceId2, 6);
+
+    /**
+     * Mock class for a flow entry.
+     */
+    private static class MockFlowEntry implements FlowEntry {
+        final DeviceId deviceId;
+        final long baseValue;
+        TrafficTreatment treatment;
+        TrafficSelector selector;
+
+        public MockFlowEntry(DeviceId deviceId, long id) {
+            this.deviceId = deviceId;
+            this.baseValue = id * 100;
+        }
+
+        @Override
+        public FlowEntryState state() {
+            return FlowEntryState.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 lastSeen() {
+            return baseValue + 44;
+        }
+
+        @Override
+        public int errType() {
+            return 0;
+        }
+
+        @Override
+        public int errCode() {
+            return 0;
+        }
+
+        @Override
+        public FlowId id() {
+            final long id = baseValue + 55;
+            return FlowId.valueOf(id);
+        }
+
+        @Override
+        public short appId() {
+            return 2;
+        }
+
+        @Override
+        public GroupId groupId() {
+            return new DefaultGroupId(3);
+        }
+
+        @Override
+        public int priority() {
+            return (int) (baseValue + 66);
+        }
+
+        @Override
+        public DeviceId deviceId() {
+            return deviceId;
+        }
+
+        @Override
+        public TrafficSelector selector() {
+            return selector;
+        }
+
+        @Override
+        public TrafficTreatment treatment() {
+            return treatment;
+        }
+
+        @Override
+        public int timeout() {
+            return (int) (baseValue + 77);
+        }
+
+        @Override
+        public boolean isPermanent() {
+            return false;
+        }
+    }
+
+    public FlowsResourceTest() {
+        super("org.onosproject.rest");
+    }
+
+    /**
+     * Populates some flows used as testing data.
+     */
+    private void setupMockFlows() {
+        flow2.treatment = DefaultTrafficTreatment.builder()
+                .add(new L0ModificationInstruction.ModLambdaInstruction(
+                        L0ModificationInstruction.L0SubType.LAMBDA, (short) 4))
+                .add(new L0ModificationInstruction.ModLambdaInstruction(
+                        L0ModificationInstruction.L0SubType.LAMBDA, (short) 5))
+                .setEthDst(MacAddress.BROADCAST)
+                .build();
+        flow2.selector = DefaultTrafficSelector.builder()
+                .matchEthType((short) 3)
+                .matchIPProtocol((byte) 9)
+                .build();
+        flow4.treatment = DefaultTrafficTreatment.builder()
+                .add(new L0ModificationInstruction.ModLambdaInstruction(
+                L0ModificationInstruction.L0SubType.LAMBDA, (short) 6))
+                .build();
+        final Set<FlowEntry> flows1 = new HashSet<>();
+        flows1.add(flow1);
+        flows1.add(flow2);
+
+        final Set<FlowEntry> flows2 = new HashSet<>();
+        flows1.add(flow3);
+        flows1.add(flow4);
+
+        rules.put(deviceId1, flows1);
+        rules.put(deviceId2, flows2);
+
+        expect(mockFlowService.getFlowEntries(deviceId1))
+                .andReturn(rules.get(deviceId1)).anyTimes();
+        expect(mockFlowService.getFlowEntries(deviceId2))
+                .andReturn(rules.get(deviceId2)).anyTimes();
+    }
+
+    /**
+     * Sets up the global values for all the tests.
+     */
+    @Before
+    public void setUp() {
+        // Mock device service
+        expect(mockDeviceService.getDevice(deviceId1))
+                .andReturn(device1);
+        expect(mockDeviceService.getDevice(deviceId2))
+                .andReturn(device2);
+        expect(mockDeviceService.getDevices())
+                .andReturn(ImmutableSet.of(device1, device2));
+
+        // Register the services needed for the test
+        final CodecManager codecService =  new CodecManager();
+        codecService.activate();
+        ServiceDirectory testDirectory =
+                new TestServiceDirectory()
+                        .add(FlowRuleService.class, mockFlowService)
+                        .add(DeviceService.class, mockDeviceService)
+                        .add(CodecService.class, codecService);
+
+        BaseResource.setServiceDirectory(testDirectory);
+    }
+
+    /**
+     * Cleans up and verifies the mocks.
+     *
+     * @throws Exception if the super teardown fails.
+     */
+    @After
+    public void tearDown() throws Exception {
+        super.tearDown();
+        verify(mockFlowService);
+    }
+
+    /**
+     * Hamcrest matcher to check that a flow representation in JSON matches
+     * the actual flow entry.
+     */
+    public static class FlowJsonMatcher extends TypeSafeMatcher<JsonObject> {
+        private final FlowEntry flow;
+        private String reason = "";
+
+        public FlowJsonMatcher(FlowEntry flowValue) {
+            flow = flowValue;
+        }
+
+        @Override
+        public boolean matchesSafely(JsonObject jsonFlow) {
+            // check id
+            final String jsonId = jsonFlow.get("id").asString();
+            final String flowId = Long.toString(flow.id().value());
+            if (!jsonId.equals(flowId)) {
+                reason = "id " + flow.id().toString();
+                return false;
+            }
+
+            // check application id
+            final int jsonAppId = jsonFlow.get("appId").asInt();
+            if (jsonAppId != flow.appId()) {
+                reason = "appId " + Short.toString(flow.appId());
+                return false;
+            }
+
+            // check device id
+            final String jsonDeviceId = jsonFlow.get("deviceId").asString();
+            if (!jsonDeviceId.equals(flow.deviceId().toString())) {
+                reason = "deviceId " + flow.deviceId();
+                return false;
+            }
+
+            // check treatment and instructions array
+            if (flow.treatment() != null) {
+                final JsonObject jsonTreatment = jsonFlow.get("treatment").asObject();
+                final JsonArray jsonInstructions = jsonTreatment.get("instructions").asArray();
+                if (flow.treatment().instructions().size() != jsonInstructions.size()) {
+                    reason = "instructions array size of " +
+                            Integer.toString(flow.treatment().instructions().size());
+                    return false;
+                }
+                for (final Instruction instruction : flow.treatment().instructions()) {
+                    boolean instructionFound = false;
+                    final String instructionString = instruction.toString();
+                    for (int instructionIndex = 0; instructionIndex < jsonInstructions.size(); instructionIndex++) {
+                        final JsonValue value = jsonInstructions.get(instructionIndex);
+                        if (value.asString().equals(instructionString)) {
+                            instructionFound = true;
+                        }
+                    }
+                    if (!instructionFound) {
+                        reason = "instruction " + instructionString;
+                        return false;
+                    }
+                }
+            }
+
+            // check selector and criteria array
+            if (flow.selector() != null) {
+                final JsonObject jsonTreatment = jsonFlow.get("selector").asObject();
+                final JsonArray jsonCriteria = jsonTreatment.get("criteria").asArray();
+                if (flow.selector().criteria().size() != jsonCriteria.size()) {
+                    reason = "criteria array size of " +
+                            Integer.toString(flow.selector().criteria().size());
+                    return false;
+                }
+                for (final Criterion criterion : flow.selector().criteria()) {
+                    boolean criterionFound = false;
+                    final String criterionString = criterion.toString();
+                    for (int criterionIndex = 0; criterionIndex < jsonCriteria.size(); criterionIndex++) {
+                        final JsonValue value = jsonCriteria.get(criterionIndex);
+                        if (value.asString().equals(criterionString)) {
+                            criterionFound = true;
+                        }
+                    }
+                    if (!criterionFound) {
+                        reason = "criterion " + criterionString;
+                        return false;
+                    }
+                }
+            }
+
+            return true;
+        }
+
+        @Override
+        public void describeTo(Description description) {
+            description.appendText(reason);
+        }
+    }
+
+    /**
+     * Factory to allocate a flow matcher.
+     *
+     * @param flow flow object we are looking for
+     * @return matcher
+     */
+    private static FlowJsonMatcher matchesFlow(FlowEntry flow) {
+        return new FlowJsonMatcher(flow);
+    }
+
+    /**
+     * Hamcrest matcher to check that a flow is represented properly in a JSON
+     * array of flows.
+     */
+    public static class FlowJsonArrayMatcher extends TypeSafeMatcher<JsonArray> {
+        private final FlowEntry flow;
+        private String reason = "";
+
+        public FlowJsonArrayMatcher(FlowEntry flowValue) {
+            flow = flowValue;
+        }
+
+        @Override
+        public boolean matchesSafely(JsonArray json) {
+            boolean flowFound = false;
+
+            for (int jsonFlowIndex = 0; jsonFlowIndex < json.size();
+                 jsonFlowIndex++) {
+
+                final JsonObject jsonFlow = json.get(jsonFlowIndex).asObject();
+
+                final String flowId = Long.toString(flow.id().value());
+                final String jsonFlowId = jsonFlow.get("id").asString();
+                if (jsonFlowId.equals(flowId)) {
+                    flowFound = true;
+
+                    //  We found the correct flow, check attribute values
+                    assertThat(jsonFlow, matchesFlow(flow));
+                }
+            }
+            if (!flowFound) {
+                reason = "Flow with id " + flow.id().toString() + " not found";
+                return false;
+            } else {
+                return true;
+            }
+        }
+
+        @Override
+        public void describeTo(Description description) {
+            description.appendText(reason);
+        }
+    }
+
+    /**
+     * Factory to allocate a flow array matcher.
+     *
+     * @param flow flow object we are looking for
+     * @return matcher
+     */
+    private static FlowJsonArrayMatcher hasFlow(FlowEntry flow) {
+        return new FlowJsonArrayMatcher(flow);
+    }
+
+    /**
+     * Tests the result of the rest api GET when there are no flows.
+     */
+    @Test
+    public void testFlowsEmptyArray() {
+        expect(mockFlowService.getFlowEntries(deviceId1))
+                .andReturn(null).anyTimes();
+        expect(mockFlowService.getFlowEntries(deviceId2))
+                .andReturn(null).anyTimes();
+        replay(mockFlowService);
+        replay(mockDeviceService);
+        final WebResource rs = resource();
+        final String response = rs.path("flows").get(String.class);
+        assertThat(response, is("{\"flows\":[]}"));
+    }
+
+    /**
+     * Tests the result of the rest api GET when there are active flows.
+     */
+    @Test
+    public void testFlowsPopulatedArray() {
+        setupMockFlows();
+        replay(mockFlowService);
+        replay(mockDeviceService);
+        final WebResource rs = resource();
+        final String response = rs.path("flows").get(String.class);
+        final JsonObject result = JsonObject.readFrom(response);
+        assertThat(result, notNullValue());
+
+        assertThat(result.names(), hasSize(1));
+        assertThat(result.names().get(0), is("flows"));
+        final JsonArray jsonFlows = result.get("flows").asArray();
+        assertThat(jsonFlows, notNullValue());
+        assertThat(jsonFlows, hasFlow(flow1));
+        assertThat(jsonFlows, hasFlow(flow2));
+        assertThat(jsonFlows, hasFlow(flow3));
+        assertThat(jsonFlows, hasFlow(flow4));
+    }
+
+    /**
+     * Tests the result of a rest api GET for a device.
+     */
+    @Test
+    public void testFlowsSingleDevice() {
+        setupMockFlows();
+        final Set<FlowEntry> flows = new HashSet<>();
+        flows.add(flow5);
+        flows.add(flow6);
+        expect(mockFlowService.getFlowEntries(anyObject()))
+                .andReturn(flows).anyTimes();
+        replay(mockFlowService);
+        replay(mockDeviceService);
+        final WebResource rs = resource();
+        final String response = rs.path("flows/" + deviceId3).get(String.class);
+        final JsonObject result = JsonObject.readFrom(response);
+        assertThat(result, notNullValue());
+
+        assertThat(result.names(), hasSize(1));
+        assertThat(result.names().get(0), is("flows"));
+        final JsonArray jsonFlows = result.get("flows").asArray();
+        assertThat(jsonFlows, notNullValue());
+        assertThat(jsonFlows, hasFlow(flow5));
+        assertThat(jsonFlows, hasFlow(flow6));
+    }
+
+    /**
+     * Tests the result of a rest api GET for a device.
+     */
+    @Test
+    public void testFlowsSingleDeviceWithFlowId() {
+        setupMockFlows();
+        final Set<FlowEntry> flows = new HashSet<>();
+        flows.add(flow5);
+        flows.add(flow6);
+        expect(mockFlowService.getFlowEntries(anyObject()))
+                .andReturn(flows).anyTimes();
+        replay(mockFlowService);
+        replay(mockDeviceService);
+        final WebResource rs = resource();
+        final String response = rs.path("flows/" + deviceId3 + "/"
+                + Long.toString(flow5.id().value())).get(String.class);
+        final JsonObject result = JsonObject.readFrom(response);
+        assertThat(result, notNullValue());
+
+        assertThat(result.names(), hasSize(1));
+        assertThat(result.names().get(0), is("flows"));
+        final JsonArray jsonFlows = result.get("flows").asArray();
+        assertThat(jsonFlows, notNullValue());
+        assertThat(jsonFlows, hasFlow(flow5));
+        assertThat(jsonFlows, not(hasFlow(flow6)));
+    }
+
+    /**
+     * Tests that a fetch of a non-existent device object throws an exception.
+     */
+    @Test
+    public void testBadGet() {
+        expect(mockFlowService.getFlowEntries(deviceId1))
+                .andReturn(null).anyTimes();
+        expect(mockFlowService.getFlowEntries(deviceId2))
+                .andReturn(null).anyTimes();
+        replay(mockFlowService);
+        replay(mockDeviceService);
+
+        WebResource rs = resource();
+        try {
+            rs.path("flows/0").get(String.class);
+            fail("Fetch of non-existent device did not throw an exception");
+        } catch (UniformInterfaceException ex) {
+            assertThat(ex.getMessage(),
+                    containsString("returned a response status of"));
+        }
+    }
+}

@@ -256,6 +256,7 @@ public class IntentsResourceTest extends JerseyTest {
     private static IntentJsonArrayMatcher hasIntent(Intent intent) {
         return new IntentJsonArrayMatcher(intent);
     }
+
     @Before
     public void setUp() {
         expect(mockIntentService.getIntents()).andReturn(intents).anyTimes();

@@ -63,10 +63,7 @@
             <scope>test</scope>
         </dependency>
 
-        <dependency>
-            <groupId>com.google.guava</groupId>
-            <artifactId>guava</artifactId>
-        </dependency>
+
 
         <dependency>
             <groupId>com.sun.jersey</groupId>
@@ -131,6 +128,7 @@
                             com.fasterxml.jackson.databind,
                             com.fasterxml.jackson.databind.node,
                             com.google.common.base.*,
+                            com.google.common.collect.*,
                             org.eclipse.jetty.websocket.*,
                             org.onlab.util.*,
                             org.onlab.osgi.*,