Adding ServerSentEvents to Rest Southbound interface

Change-Id: I77411df608be8a1cab9d828db17202f88b969a0f
diff --git a/protocols/rest/api/src/main/java/org/onosproject/protocol/http/HttpSBController.java b/protocols/rest/api/src/main/java/org/onosproject/protocol/http/HttpSBController.java
index ada5496..0f5b32b 100644
--- a/protocols/rest/api/src/main/java/org/onosproject/protocol/http/HttpSBController.java
+++ b/protocols/rest/api/src/main/java/org/onosproject/protocol/http/HttpSBController.java
@@ -18,8 +18,10 @@
 
 import java.io.InputStream;
 import java.util.Map;
+import java.util.function.Consumer;
 
 import javax.ws.rs.core.MediaType;
+import javax.ws.rs.sse.InboundSseEvent;
 
 import org.onlab.packet.IpAddress;
 import org.onosproject.net.DeviceId;
@@ -125,7 +127,8 @@
     InputStream get(DeviceId device, String request, MediaType mediaType);
 
     /**
-     * Does a HTTP POST request with specified parameters to the device.
+     * Does a HTTP POST request with specified parameters to the device and
+     * extracts an object of type T from the response entity field.
      *
      * @param <T> post return type
      * @param device device to make the request to
@@ -138,5 +141,27 @@
      */
      <T> T post(DeviceId device, String request, InputStream payload, MediaType mediaType, Class<T> responseClass);
 
+    /**
+     * Does a HTTP GET against a Server Sent Events (SSE_INBOUND) resource on the device.
+     *
+     * This is a low level function that can take callbacks.
+     * For a higher level function that emits events based on this callback
+     * see startServerSentEvents() in the RestSBController
+     *
+     * @param deviceId device to make the request to
+     * @param request url of the request
+     * @param onEvent A consumer of inbound SSE_INBOUND events
+     * @param onError A consumer of inbound SSE_INBOUND errors
+     * @return status Commonly used status codes defined by HTTP
+     */
+     int getServerSentEvents(DeviceId deviceId, String request,
+                             Consumer<InboundSseEvent> onEvent, Consumer<Throwable> onError);
 
+    /**
+     * Cancels a Server Sent Events listener to a device.
+     *
+     * @param deviceId device to cancel the listener for
+     * @return status Commonly used status codes defined by HTTP
+     */
+    int cancelServerSentEvents(DeviceId deviceId);
 }
diff --git a/protocols/rest/api/src/main/java/org/onosproject/protocol/http/ctl/HttpSBControllerImpl.java b/protocols/rest/api/src/main/java/org/onosproject/protocol/http/ctl/HttpSBControllerImpl.java
index e8fcca0..e4ba243 100644
--- a/protocols/rest/api/src/main/java/org/onosproject/protocol/http/ctl/HttpSBControllerImpl.java
+++ b/protocols/rest/api/src/main/java/org/onosproject/protocol/http/ctl/HttpSBControllerImpl.java
@@ -45,6 +45,8 @@
 import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.Response;
 import javax.ws.rs.core.Response.Status;
+import javax.ws.rs.sse.InboundSseEvent;
+import javax.ws.rs.sse.SseEventSource;
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
@@ -57,6 +59,7 @@
 import java.util.Base64;
 import java.util.Map;
 import java.util.concurrent.ConcurrentHashMap;
+import java.util.function.Consumer;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 
@@ -80,6 +83,7 @@
 
     private final Map<DeviceId, RestSBDevice> deviceMap = new ConcurrentHashMap<>();
     private final Map<DeviceId, Client> clientMap = new ConcurrentHashMap<>();
+    private final Map<DeviceId, SseEventSource> sseEventSourceMap = new ConcurrentHashMap<>();
 
     public Map<DeviceId, RestSBDevice> getDeviceMap() {
         return deviceMap;
@@ -89,6 +93,10 @@
         return clientMap;
     }
 
+    public Map<DeviceId, SseEventSource> getSseEventSourceMap() {
+        return sseEventSourceMap;
+    }
+
     @Override
     public Map<DeviceId, RestSBDevice> getDevices() {
         return ImmutableMap.copyOf(deviceMap);
@@ -121,6 +129,7 @@
     public void removeDevice(DeviceId deviceId) {
         clientMap.remove(deviceId);
         deviceMap.remove(deviceId);
+        sseEventSourceMap.remove(deviceId);
     }
 
     @Override
@@ -251,6 +260,58 @@
         return response.getStatus();
     }
 
+    @Override
+    public int getServerSentEvents(DeviceId deviceId, String request,
+                                   Consumer<InboundSseEvent> onEvent,
+                                   Consumer<Throwable> onError) {
+        if (deviceId == null) {
+            log.warn("Device ID is null", request);
+            return Status.PRECONDITION_FAILED.getStatusCode();
+        }
+
+        if (request == null || request.isEmpty()) {
+            log.warn("Request cannot be empty", request);
+            return Status.PRECONDITION_FAILED.getStatusCode();
+        }
+
+        if (sseEventSourceMap.containsKey(deviceId)) {
+            log.warn("Device", deviceId, "is already listening to an SSE stream");
+            return Status.CONFLICT.getStatusCode();
+        }
+
+        WebTarget wt = getWebTarget(deviceId, request);
+        SseEventSource sseEventSource = SseEventSource.target(wt).build();
+        sseEventSource.register(onEvent, onError);
+        sseEventSource.open();
+        if (sseEventSource.isOpen()) {
+            sseEventSourceMap.put(deviceId, sseEventSource);
+            log.info("Opened Server Sent Events request to ", request, "on", deviceId);
+            while (sseEventSource.isOpen()) {
+                try {
+                    Thread.sleep(1010);
+                    System.out.println("Listening for SSEs");
+                } catch (InterruptedException e) {
+                    log.error("Error", e);
+                }
+            }
+            return Status.NO_CONTENT.getStatusCode();
+        } else {
+            log.error("Unable to open Server Sent Events request to ", request, "to", deviceId);
+            return Status.INTERNAL_SERVER_ERROR.getStatusCode();
+        }
+    }
+
+    @Override
+    public int cancelServerSentEvents(DeviceId deviceId) {
+        if (sseEventSourceMap.containsKey(deviceId)) {
+            sseEventSourceMap.get(deviceId).close();
+            sseEventSourceMap.remove(deviceId);
+            return Status.OK.getStatusCode();
+        } else {
+            return Status.NOT_FOUND.getStatusCode();
+        }
+    }
+
     private MediaType typeOfMediaType(String type) {
         switch (type) {
         case XML:
diff --git a/protocols/rest/api/src/main/java/org/onosproject/protocol/rest/RestSBController.java b/protocols/rest/api/src/main/java/org/onosproject/protocol/rest/RestSBController.java
index 551ddcb..c67609a 100644
--- a/protocols/rest/api/src/main/java/org/onosproject/protocol/rest/RestSBController.java
+++ b/protocols/rest/api/src/main/java/org/onosproject/protocol/rest/RestSBController.java
@@ -56,4 +56,22 @@
      * @return the corresponding REST proxied device
      */
     RestSBDevice getProxySBDevice(DeviceId deviceId);
+
+    /**
+     * Call on the Rest SB interface for a device to request ServerSentEvents from events URL.
+     *
+     * These events will be converted to ONOS events and forwarded to any registered listener
+     * through the EventDispatcher system. Drivers can implement listeners in their
+     * own particular way depending on the type of data expected.
+     *
+     * To register and unregister listeners use the addListener and removeListener
+     * methods. These listeners will get messages from all devices.
+     *
+     * To stop a particular device's event stream use the cancelServerSentEvents
+     * for that device.
+     *
+     * @param deviceId the id of the device exposed to ONOS
+     * @param eventsUrl The resource on the device that supplies an SSE_INBOUND stream
+     */
+    void startServerSentEvents(DeviceId deviceId, String eventsUrl);
 }
diff --git a/protocols/rest/api/src/main/java/org/onosproject/protocol/rest/RestSBEventListener.java b/protocols/rest/api/src/main/java/org/onosproject/protocol/rest/RestSBEventListener.java
new file mode 100644
index 0000000..d96599c
--- /dev/null
+++ b/protocols/rest/api/src/main/java/org/onosproject/protocol/rest/RestSBEventListener.java
@@ -0,0 +1,25 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.protocol.rest;
+
+import org.onosproject.event.EventListener;
+
+/**
+ * Listener interface for Server Sent Events from Rest SB.
+ */
+public interface RestSBEventListener extends EventListener<RestSBServerSentEvent> {
+}
diff --git a/protocols/rest/api/src/main/java/org/onosproject/protocol/rest/RestSBServerSentEvent.java b/protocols/rest/api/src/main/java/org/onosproject/protocol/rest/RestSBServerSentEvent.java
new file mode 100644
index 0000000..30d35ee
--- /dev/null
+++ b/protocols/rest/api/src/main/java/org/onosproject/protocol/rest/RestSBServerSentEvent.java
@@ -0,0 +1,94 @@
+/*
+ * Copyright 2018-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.protocol.rest;
+
+import org.onosproject.event.AbstractEvent;
+import org.onosproject.net.DeviceId;
+
+import javax.ws.rs.sse.InboundSseEvent;
+
+import java.util.Objects;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Event received on the REST SB interface as ServerSentEvent (SSE_INBOUND).
+ */
+public class RestSBServerSentEvent extends AbstractEvent<RestSBServerSentEvent.Type, DeviceId> {
+
+    private String id;
+    private String comment;
+    private String data;
+    private String name;
+
+    /**
+     * SSE Event types supported.
+     */
+    public enum Type {
+        SSE_INBOUND
+    }
+
+    public RestSBServerSentEvent(Type type, DeviceId deviceId, InboundSseEvent sseEvent) {
+        super(type, deviceId);
+        checkNotNull(sseEvent);
+        data = sseEvent.readData();
+        id = sseEvent.getId();
+        name = sseEvent.getName();
+        comment = sseEvent.getComment();
+    }
+
+    public String getData() {
+        return data;
+    }
+
+    public String getId() {
+        return id;
+    }
+
+    public String getComment() {
+        return comment;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public String toString() {
+        return super.toString() + ", id=" + id + ", name=" + name + ", comment=" + comment;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+        RestSBServerSentEvent that = (RestSBServerSentEvent) o;
+        return Objects.equals(id, that.id) &&
+                Objects.equals(comment, that.comment) &&
+                Objects.equals(data, that.data) &&
+                Objects.equals(name, that.name);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id, comment, data, name);
+    }
+}
diff --git a/protocols/rest/ctl/BUCK b/protocols/rest/ctl/BUCK
index 3fdfd57..c12164d 100644
--- a/protocols/rest/ctl/BUCK
+++ b/protocols/rest/ctl/BUCK
@@ -2,6 +2,7 @@
     '//lib:CORE_DEPS',
     '//lib:jersey-client',
     '//lib:jersey-common',
+    '//lib:jersey-media-sse',
     '//lib:httpclient-osgi',
     '//lib:httpcore-osgi',
     '//lib:javax.ws.rs-api',
@@ -11,7 +12,13 @@
     '//protocols/rest/api:onos-protocols-rest-api',
 ]
 
+TEST_DEPS = [
+    '//lib:TEST_REST',
+    '//core/common:onos-core-common-tests'
+]
+
 osgi_jar_with_tests (
     deps = COMPILE_DEPS,
+    test_deps = TEST_DEPS
 )
 
diff --git a/protocols/rest/ctl/BUILD b/protocols/rest/ctl/BUILD
index f2b3d0c..f7fd3ea 100644
--- a/protocols/rest/ctl/BUILD
+++ b/protocols/rest/ctl/BUILD
@@ -2,6 +2,7 @@
     "@jersey_client//jar",
     "@jersey_server//jar",
     "@jersey_common//jar",
+    "@jersey_media_sse//jar",
     "@jersey_security//jar",
     "@httpclient_osgi//jar",
     "@httpcore_osgi//jar",
@@ -12,6 +13,11 @@
     "//protocols/rest/api:onos-protocols-rest-api",
 ]
 
+TEST_DEPS = TEST_REST + [
+    "//core/common:onos-core-common-tests"
+]
+
 osgi_jar_with_tests(
     deps = COMPILE_DEPS,
+    test_deps = TEST_DEPS,
 )
diff --git a/protocols/rest/ctl/pom.xml b/protocols/rest/ctl/pom.xml
index 5ff9e08..e99d193 100644
--- a/protocols/rest/ctl/pom.xml
+++ b/protocols/rest/ctl/pom.xml
@@ -39,6 +39,10 @@
             <version>${project.version}</version>
             <type>bundle</type>
         </dependency>
+        <dependency>
+            <groupId>org.glassfish.jersey.core</groupId>
+            <artifactId>jersey-media-sse</artifactId>
+        </dependency>
     </dependencies>
 
     <build>
diff --git a/protocols/rest/ctl/src/main/java/org/onosproject/protocol/rest/ctl/RestSBControllerImpl.java b/protocols/rest/ctl/src/main/java/org/onosproject/protocol/rest/ctl/RestSBControllerImpl.java
index 83737ca..a527e0e 100644
--- a/protocols/rest/ctl/src/main/java/org/onosproject/protocol/rest/ctl/RestSBControllerImpl.java
+++ b/protocols/rest/ctl/src/main/java/org/onosproject/protocol/rest/ctl/RestSBControllerImpl.java
@@ -20,15 +20,23 @@
 import org.apache.felix.scr.annotations.Activate;
 import org.apache.felix.scr.annotations.Component;
 import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
 import org.apache.felix.scr.annotations.Service;
+import org.onosproject.event.EventDeliveryService;
+import org.onosproject.event.ListenerRegistry;
+import org.onosproject.event.ListenerService;
 import org.onosproject.net.DeviceId;
 import org.onosproject.protocol.http.ctl.HttpSBControllerImpl;
 import org.onosproject.protocol.rest.RestSBController;
 import org.onosproject.protocol.rest.RestSBDevice;
+import org.onosproject.protocol.rest.RestSBEventListener;
+import org.onosproject.protocol.rest.RestSBServerSentEvent;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 import javax.ws.rs.client.WebTarget;
+import javax.ws.rs.sse.InboundSseEvent;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
@@ -39,15 +47,23 @@
  */
 @Component(immediate = true)
 @Service
-public class RestSBControllerImpl extends HttpSBControllerImpl implements RestSBController {
+public class RestSBControllerImpl extends HttpSBControllerImpl
+        implements RestSBController, ListenerService<RestSBServerSentEvent, RestSBEventListener> {
 
     private static final Logger log =
             LoggerFactory.getLogger(RestSBControllerImpl.class);
 
+    @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+    protected EventDeliveryService eventDispatcher;
+
+    protected final ListenerRegistry<RestSBServerSentEvent, RestSBEventListener> listenerRegistry =
+            new ListenerRegistry<>();
+
     private final Map<DeviceId, RestSBDevice> proxiedDeviceMap = new ConcurrentHashMap<>();
 
     @Activate
     public void activate() {
+        eventDispatcher.addSink(RestSBServerSentEvent.class, listenerRegistry);
         log.info("Started");
     }
 
@@ -55,6 +71,7 @@
     public void deactivate() {
         this.getClientMap().clear();
         this.getDeviceMap().clear();
+        this.getSseEventSourceMap().clear();
         log.info("Stopped");
     }
 
@@ -118,4 +135,36 @@
         }
 
     }
+
+    @Override
+    public void startServerSentEvents(DeviceId deviceId, String eventsUrl) {
+        this.getServerSentEvents(deviceId, eventsUrl,
+                (event) -> sendEvent(event, deviceId),
+                (error) -> log.error("Unable to handle {} SSEvent from {}. {}",
+                        eventsUrl, deviceId, error));
+    }
+
+    @Override
+    public void addListener(RestSBEventListener listener) {
+        listenerRegistry.addListener(listener);
+    }
+
+    @Override
+    public void removeListener(RestSBEventListener listener) {
+        listenerRegistry.removeListener(listener);
+    }
+
+    /**
+     * Safely posts the specified event to the local event dispatcher.
+     * If there is no event dispatcher or if the event is null, this method
+     * is a noop.
+     * @param sseEvent event to be posted; may be null
+     * @param deviceId the device that sent the event
+     */
+    protected void sendEvent(InboundSseEvent sseEvent, DeviceId deviceId) {
+        if (sseEvent != null && eventDispatcher != null) {
+            eventDispatcher.post(new RestSBServerSentEvent(
+                    RestSBServerSentEvent.Type.SSE_INBOUND, deviceId, sseEvent));
+        }
+    }
 }
diff --git a/protocols/rest/ctl/src/test/java/org/onosproject/protocol/rest/ctl/RestSBControllerImplTest.java b/protocols/rest/ctl/src/test/java/org/onosproject/protocol/rest/ctl/RestSBControllerImplTest.java
index 8f90057..fa9f952 100644
--- a/protocols/rest/ctl/src/test/java/org/onosproject/protocol/rest/ctl/RestSBControllerImplTest.java
+++ b/protocols/rest/ctl/src/test/java/org/onosproject/protocol/rest/ctl/RestSBControllerImplTest.java
@@ -16,32 +16,156 @@
 
 package org.onosproject.protocol.rest.ctl;
 
+import org.apache.commons.io.IOUtils;
+import org.glassfish.jersey.server.ResourceConfig;
+import org.glassfish.jersey.test.JerseyTest;
+import org.glassfish.jersey.test.TestProperties;
 import org.junit.Before;
 import org.junit.Test;
+import org.onlab.junit.TestUtils;
 import org.onlab.packet.IpAddress;
 import org.onosproject.protocol.rest.DefaultRestSBDevice;
 import org.onosproject.protocol.rest.RestSBDevice;
+import org.onosproject.common.event.impl.TestEventDispatcher;
+import org.onosproject.protocol.rest.RestSBEventListener;
+
+import javax.ws.rs.Consumes;
+import javax.ws.rs.DELETE;
+import javax.ws.rs.GET;
+import javax.ws.rs.PATCH;
+import javax.ws.rs.POST;
+import javax.ws.rs.PUT;
+import javax.ws.rs.Path;
+import javax.ws.rs.Produces;
+import javax.ws.rs.core.Application;
+import javax.ws.rs.core.Context;
+import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
+import javax.ws.rs.sse.InboundSseEvent;
+import javax.ws.rs.sse.OutboundSseEvent;
+import javax.ws.rs.sse.Sse;
+import javax.ws.rs.sse.SseEventSink;
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.HttpURLConnection;
+import java.nio.charset.StandardCharsets;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Consumer;
 
 import static org.junit.Assert.*;
 
 /**
  * Basic testing for RestSBController.
  */
-public class RestSBControllerImplTest {
+public class RestSBControllerImplTest extends JerseyTest {
+    private static final String SAMPLE_PAYLOAD = "{ \"msg\": \"ONOS Rocks!\" }";
 
     RestSBControllerImpl controller;
 
     RestSBDevice device1;
     RestSBDevice device2;
 
+    /**
+     * Mockup of an arbitrary device.
+     */
+    @Path("testme")
+    public static class HelloResource {
+        @POST
+        @Consumes(MediaType.APPLICATION_JSON)
+        @Produces(MediaType.APPLICATION_JSON)
+        public Response post(InputStream payload) throws IOException {
+            String responseText = IOUtils.toString(payload, StandardCharsets.UTF_8);
+            if (responseText.equalsIgnoreCase(SAMPLE_PAYLOAD)) {
+                return Response.ok().build();
+            }
+            return Response.status(Response.Status.EXPECTATION_FAILED).build();
+        }
+
+        @POST
+        @Path("testpostreturnstring")
+        @Consumes(MediaType.APPLICATION_JSON)
+        @Produces(MediaType.APPLICATION_JSON)
+        public Response postReturnString(InputStream payload) throws IOException {
+            String responseText = IOUtils.toString(payload, StandardCharsets.UTF_8);
+            if (responseText.equalsIgnoreCase(SAMPLE_PAYLOAD)) {
+                return Response.ok().entity("OK").build();
+            }
+            return Response.status(Response.Status.EXPECTATION_FAILED).entity("Failed").build();
+        }
+
+        @PUT
+        @Consumes(MediaType.APPLICATION_JSON)
+        @Produces(MediaType.APPLICATION_JSON)
+        public Response put(InputStream payload) throws IOException {
+            String responseText = IOUtils.toString(payload, StandardCharsets.UTF_8);
+            if (responseText.equalsIgnoreCase(SAMPLE_PAYLOAD)) {
+                return Response.ok().build();
+            }
+            return Response.status(Response.Status.EXPECTATION_FAILED).build();
+        }
+
+        @PATCH
+        @Consumes(MediaType.APPLICATION_JSON)
+        @Produces(MediaType.APPLICATION_JSON)
+        public Response patch(InputStream payload) throws IOException {
+            String responseText = IOUtils.toString(payload, StandardCharsets.UTF_8);
+            if (responseText.equalsIgnoreCase(SAMPLE_PAYLOAD)) {
+                return Response.ok().build();
+            }
+            return Response.status(Response.Status.EXPECTATION_FAILED).build();
+        }
+
+        @GET
+        public String getHello() {
+            return SAMPLE_PAYLOAD;
+        }
+
+        @DELETE
+        public int delete() {
+            return Response.Status.NO_CONTENT.getStatusCode();
+        }
+
+        @GET
+        @Path("server-sent-events")
+        @Produces(MediaType.SERVER_SENT_EVENTS)
+        public void getServerSentEvents(@Context SseEventSink eventSink, @Context Sse sse) throws InterruptedException {
+            new Thread(() -> {
+                try {
+                    for (int i = 0; i < 10; i++) {
+                        // ... code that waits 0.1 second
+                            Thread.sleep(100L);
+                        final OutboundSseEvent event = sse.newEventBuilder()
+                                .id(String.valueOf(i))
+                                .name("message-to-rest-sb")
+                                .data(String.class, "Test message " + i + "!")
+                                .build();
+                        eventSink.send(event);
+                        System.out.println("Message " + i + " sent");
+                    }
+                } catch (InterruptedException e) {
+                    e.printStackTrace();
+                }
+            }).start();
+        }
+
+    }
+
+    @Override
+    protected Application configure() {
+        set(TestProperties.CONTAINER_PORT, 8080);
+        return new ResourceConfig(HelloResource.class);
+    }
 
     @Before
-    public void setUp() {
+    public void setUpTest() {
         controller = new RestSBControllerImpl();
+        TestUtils.setField(controller, "eventDispatcher", new TestEventDispatcher());
         controller.activate();
         device1 = new DefaultRestSBDevice(IpAddress.valueOf("127.0.0.1"), 8080, "foo", "bar", "http", null, true);
         device2 = new DefaultRestSBDevice(IpAddress.valueOf("127.0.0.2"), 8080, "foo1", "bar2", "http", null, true);
         controller.addDevice(device1);
+
     }
 
     @Test
@@ -56,4 +180,134 @@
         controller.removeDevice(device2.deviceId());
         assertFalse("Device2 not removed", controller.getDevices().containsValue(device2));
     }
+
+    /**
+     * Tests the post function of the REST SB Controller.
+     */
+    @Test
+    public void testPost() {
+        InputStream payload = new ByteArrayInputStream(SAMPLE_PAYLOAD.getBytes(StandardCharsets.UTF_8));
+        int response = controller.post(device1.deviceId(), "/testme", payload, MediaType.APPLICATION_JSON_TYPE);
+        assertEquals(HttpURLConnection.HTTP_OK, response);
+    }
+
+    /**
+     * Tests the put function of the REST SB Controller.
+     */
+    @Test
+    public void testPut() {
+        InputStream payload = new ByteArrayInputStream(SAMPLE_PAYLOAD.getBytes(StandardCharsets.UTF_8));
+        int response = controller.put(device1.deviceId(), "/testme", payload, MediaType.APPLICATION_JSON_TYPE);
+        assertEquals(HttpURLConnection.HTTP_OK, response);
+    }
+
+    @Test
+    public void testPatch() {
+        InputStream payload = new ByteArrayInputStream(SAMPLE_PAYLOAD.getBytes(StandardCharsets.UTF_8));
+        int response = controller.patch(device1.deviceId(), "/testme", payload, MediaType.APPLICATION_JSON_TYPE);
+        assertEquals(HttpURLConnection.HTTP_OK, response);
+    }
+
+    /**
+     * Tests the delete function of the REST SB Controller.
+     */
+    @Test
+    public void testDelete() {
+        int response = controller.delete(device1.deviceId(), "/testme", null, null);
+        assertEquals(HttpURLConnection.HTTP_OK, response);
+    }
+
+    /**
+     * Tests the get function of the REST SB Controller.
+     */
+    @Test
+    public void testGet() throws IOException {
+        InputStream payload = controller.get(device1.deviceId(), "/testme", MediaType.APPLICATION_JSON_TYPE);
+        String responseText = IOUtils.toString(payload, StandardCharsets.UTF_8);
+        assertEquals(SAMPLE_PAYLOAD, responseText);
+    }
+
+    /**
+     * Tests the post function of the REST SB Controller.
+     */
+    @Test
+    public void testPostReturnString() {
+        InputStream payload = new ByteArrayInputStream(SAMPLE_PAYLOAD.getBytes(StandardCharsets.UTF_8));
+        String result = controller.post(device1.deviceId(), "/testme/testpostreturnstring",
+                payload, MediaType.APPLICATION_JSON_TYPE, String.class);
+        assertEquals("OK", result);
+    }
+
+    /**
+     * Tests the low level getServerSentEvents function of the REST SB Controller.
+     *
+     * Note: If the consumer throws an error it will not be propagated back up
+     * to here - instead the source will go in to error and no more callbacks
+     * will be executed
+     */
+    @Test
+    public void testGetServerSentEvents() {
+        Consumer<InboundSseEvent> sseEventConsumer = (event) -> {
+            System.out.println("ServerSentEvent received: " + event);
+            assertEquals("message-to-rest-sb", event.getName());
+            // Just to show it works we stop before the last message is sent
+            if (Integer.parseInt(event.getId()) == 8) {
+                controller.cancelServerSentEvents(device1.deviceId());
+            }
+        };
+
+        Consumer<Throwable> sseError = (error) -> {
+            System.err.println(error);
+            controller.cancelServerSentEvents(device1.deviceId());
+            //fail(error.toString()); //Does nothing as it's in lambda scope
+        };
+
+        int response = controller.getServerSentEvents(device1.deviceId(),
+                "/testme/server-sent-events",
+                sseEventConsumer,
+                sseError
+        );
+        assertEquals(204, response);
+    }
+
+    /**
+     * Test of cancelling of events from a device - in this case there should not be any.
+     */
+    @Test
+    public void testCancelServerSentEvents() {
+        assertEquals(404, controller.cancelServerSentEvents(device1.deviceId()));
+    }
+
+    /**
+     * Test the high level API for Server Sent Events.
+     */
+    @Test
+    public void testStartServerSentEvents() {
+        AtomicInteger listener1Count = new AtomicInteger();
+        AtomicInteger listener2Count = new AtomicInteger();
+
+        RestSBEventListener listener1 = event -> {
+            System.out.println("Event on Lsnr1: " + event);
+            listener1Count.incrementAndGet();
+            if (Integer.parseInt(event.getId()) == 8) {
+                controller.cancelServerSentEvents(device1.deviceId());
+            }
+        };
+
+        RestSBEventListener listener2 = event -> {
+            listener2Count.incrementAndGet();
+            System.out.println("Event on Lsnr2: " + event);
+        };
+
+        controller.addListener(listener1);
+        controller.addListener(listener2);
+
+        controller.startServerSentEvents(device1.deviceId(), "/testme/server-sent-events");
+
+        controller.removeListener(listener1);
+        controller.removeListener(listener2);
+
+        assertEquals(9, listener1Count.get());
+        assertEquals(9, listener2Count.get());
+    }
 }
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