ONOS-3655 - Adding Junit tests for DeviceKey subsystem, and adding DeviceKey
event, listener, store and delegate classes.  DeviceKeyManager and store
implementation will be added in the next submission.

Change-Id: I60edb1753e9ee2985ccabc2b6ec9c223867590de
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/key/DeviceKeyEvent.java b/incubator/api/src/main/java/org/onosproject/incubator/net/key/DeviceKeyEvent.java
new file mode 100644
index 0000000..8c2acb4
--- /dev/null
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/key/DeviceKeyEvent.java
@@ -0,0 +1,69 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.incubator.net.key;
+
+import com.google.common.annotations.Beta;
+import org.onosproject.event.AbstractEvent;
+
+/**
+ * Describes device key events.
+ */
+@Beta
+public class DeviceKeyEvent extends AbstractEvent<DeviceKeyEvent.Type, DeviceKey> {
+
+    /**
+     * Type of device key events.
+     */
+    public enum Type {
+        /**
+         * Signals that a new device key has been added.
+         */
+        DEVICE_KEY_ADDED,
+
+        /**
+         * Signals that a device key has been updated or changed state.
+         */
+        DEVICE_KEY_UPDATED,
+
+        /**
+         * Signals that a device key has been removed.
+         */
+        DEVICE_KEY_REMOVED
+    }
+
+    /**
+     * Creates an event of a given type, and for the specified device key.
+     *
+     * @param type      device key event type
+     * @param deviceKey event device key subject
+     */
+    public DeviceKeyEvent(Type type, DeviceKey deviceKey) {
+        super(type, deviceKey);
+    }
+
+    /**
+     * Creates an event of a given type, for the specified device key, and
+     * the current time.
+     *
+     * @param type      device key event type
+     * @param deviceKey event device key subject
+     * @param time      occurrence time
+     */
+    public DeviceKeyEvent(Type type, DeviceKey deviceKey, long time) {
+        super(type, deviceKey, time);
+    }
+}
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/key/DeviceKeyListener.java b/incubator/api/src/main/java/org/onosproject/incubator/net/key/DeviceKeyListener.java
new file mode 100644
index 0000000..c9268a4
--- /dev/null
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/key/DeviceKeyListener.java
@@ -0,0 +1,27 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.incubator.net.key;
+
+import com.google.common.annotations.Beta;
+import org.onosproject.event.EventListener;
+
+/**
+ * Listener for device key related events.
+ */
+@Beta
+public interface DeviceKeyListener extends EventListener<DeviceKeyEvent> {
+}
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/key/DeviceKeyStore.java b/incubator/api/src/main/java/org/onosproject/incubator/net/key/DeviceKeyStore.java
new file mode 100644
index 0000000..f25b662
--- /dev/null
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/key/DeviceKeyStore.java
@@ -0,0 +1,42 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.incubator.net.key;
+
+import com.google.common.annotations.Beta;
+import org.onosproject.store.Store;
+
+/**
+ * Manages inventory of device keys; not intended for direct use.
+ */
+@Beta
+public interface DeviceKeyStore extends Store<DeviceKeyEvent, DeviceKeyStoreDelegate> {
+    /**
+     * Creates or updates a device key.
+     *
+     * @param deviceKey device key
+     * @return device key event
+     */
+    DeviceKeyEvent createOrUpdateDeviceKey(DeviceKey deviceKey);
+
+    /**
+     * Deletes a device key by a specific device key identifier.
+     *
+     * @param deviceKeyId device key unique identifier
+     * @return device key event
+     */
+    DeviceKeyEvent deleteDeviceKey(DeviceKeyId deviceKeyId);
+}
diff --git a/incubator/api/src/main/java/org/onosproject/incubator/net/key/DeviceKeyStoreDelegate.java b/incubator/api/src/main/java/org/onosproject/incubator/net/key/DeviceKeyStoreDelegate.java
new file mode 100644
index 0000000..0ae7b85
--- /dev/null
+++ b/incubator/api/src/main/java/org/onosproject/incubator/net/key/DeviceKeyStoreDelegate.java
@@ -0,0 +1,27 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.incubator.net.key;
+
+import com.google.common.annotations.Beta;
+import org.onosproject.store.StoreDelegate;
+
+/**
+ * Device key store delegate abstraction.
+ */
+@Beta
+public interface DeviceKeyStoreDelegate extends StoreDelegate<DeviceKeyEvent> {
+}
diff --git a/incubator/api/src/test/java/org/onosproject/incubator/net/key/CommunityNameTest.java b/incubator/api/src/test/java/org/onosproject/incubator/net/key/CommunityNameTest.java
new file mode 100644
index 0000000..5da0f1d
--- /dev/null
+++ b/incubator/api/src/test/java/org/onosproject/incubator/net/key/CommunityNameTest.java
@@ -0,0 +1,62 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.incubator.net.key;
+
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+import static org.onlab.junit.ImmutableClassChecker.assertThatClassIsImmutable;
+
+/**
+ * Test class for CommunityName.
+ */
+public class CommunityNameTest {
+
+    final String cName = "CommunityName";
+
+    /**
+     * Checks that the CommunityName class is immutable.
+     */
+    @Test
+    public void testImmutability() {
+        assertThatClassIsImmutable(CommunityName.class);
+    }
+
+    /**
+     * Checks the construction of a community name object with a null
+     * value passed into it.
+     */
+    @Test
+    public void testCommunityNameNull() {
+        CommunityName communityName = CommunityName.communityName(null);
+
+        assertNotNull("The CommunityName should not be null.", communityName);
+        assertNull("The name should be null.", communityName.name());
+    }
+
+    /**
+     * Checks the construction of a community name object with a non-null
+     * value passed into it.
+     */
+    @Test
+    public void testCommunityName() {
+        CommunityName communityName = CommunityName.communityName(cName);
+
+        assertNotNull("The CommunityName should not be null.", communityName);
+        assertEquals("The name should match the expected value.", cName, communityName.name());
+    }
+}
diff --git a/incubator/api/src/test/java/org/onosproject/incubator/net/key/DeviceKeyIdTest.java b/incubator/api/src/test/java/org/onosproject/incubator/net/key/DeviceKeyIdTest.java
new file mode 100644
index 0000000..5f6c477
--- /dev/null
+++ b/incubator/api/src/test/java/org/onosproject/incubator/net/key/DeviceKeyIdTest.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.incubator.net.key;
+
+import com.google.common.testing.EqualsTester;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.onlab.junit.ImmutableClassChecker.assertThatClassIsImmutable;
+
+/**
+ * Test class for DeviceDeyId.
+ */
+public class DeviceKeyIdTest {
+
+    final String deviceKeyIdValue1 = "DeviceKeyId1";
+    final String deviceKeyIdValue2 = "DeviceKeyId2";
+
+    /**
+     * Checks that the DeviceKeyId class is immutable.
+     */
+    @Test
+    public void testImmutability() {
+        assertThatClassIsImmutable(DeviceKeyId.class);
+    }
+
+    /**
+     * Checks the construction of a DeviceKeyId object throws an
+     * IllegalArgumentException when the input identifier is null.
+     */
+    @Test(expected = NullPointerException.class)
+    public void testConstructionUsingNullId() {
+        DeviceKeyId.deviceKeyId(null);
+    }
+
+    /**
+     * Checks the construction of a DeviceKeyId object.
+     */
+    @Test
+    public void testConstruction() {
+        DeviceKeyId deviceKeyId = DeviceKeyId.deviceKeyId(deviceKeyIdValue1);
+        assertNotNull("The deviceKeyId should not be null.", deviceKeyId);
+        assertEquals("The id should match the expected value.",
+                     deviceKeyIdValue1, deviceKeyId.id());
+    }
+
+    /**
+     * Tests the equality of device key identifiers.
+     */
+    @Test
+    public void testEquality() {
+        DeviceKeyId deviceKeyId1 = DeviceKeyId.deviceKeyId(deviceKeyIdValue1);
+        DeviceKeyId deviceKeyId2 = DeviceKeyId.deviceKeyId(deviceKeyIdValue1);
+        DeviceKeyId deviceKeyId3 = DeviceKeyId.deviceKeyId(deviceKeyIdValue2);
+
+        new EqualsTester().addEqualityGroup(deviceKeyId1, deviceKeyId2)
+                .addEqualityGroup(deviceKeyId3)
+                .testEquals();
+    }
+}
diff --git a/incubator/api/src/test/java/org/onosproject/incubator/net/key/DeviceKeyTest.java b/incubator/api/src/test/java/org/onosproject/incubator/net/key/DeviceKeyTest.java
new file mode 100644
index 0000000..5a5699b
--- /dev/null
+++ b/incubator/api/src/test/java/org/onosproject/incubator/net/key/DeviceKeyTest.java
@@ -0,0 +1,61 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.incubator.net.key;
+
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+/**
+ * Test class for DeviceKey.
+ */
+public class DeviceKeyTest {
+
+    final String deviceKeyIdValue = "DeviceKeyId1";
+    final String deviceKeyLabel = "DeviceKeyLabel";
+    final String deviceKeySnmpName = "DeviceKeySnmpName";
+
+    /**
+     * Checks the construction of a device key name with a null
+     * value passed into it. This will throw a NullPointerException.
+     */
+    @Test(expected = NullPointerException.class)
+    public void testCreateDeviceKeyUsingCommunityNameWithNull() {
+        DeviceKey deviceKey = DeviceKey.createDeviceKeyUsingCommunityName(null, null, null);
+    }
+
+    /**
+     * Checks the construction of a device key name with non-null
+     * values passed into it.
+     */
+    @Test
+    public void testCreateDeviceKeyUsingCommunityName() {
+        DeviceKeyId deviceKeyId = DeviceKeyId.deviceKeyId(deviceKeyIdValue);
+
+        DeviceKey deviceKey = DeviceKey.createDeviceKeyUsingCommunityName(deviceKeyId,
+                                                                          deviceKeyLabel, deviceKeySnmpName);
+        assertNotNull("The deviceKey should not be null.", deviceKey);
+        assertEquals("The deviceKeyId should match as expected", deviceKeyId, deviceKey.deviceKeyId());
+        assertEquals("The label should match as expected", deviceKeyLabel, deviceKey.label());
+        assertEquals("The type should match as expected", DeviceKey.Type.COMMUNITY_NAME, deviceKey.type());
+
+        CommunityName communityName = deviceKey.asCommunityName();
+        assertNotNull("The communityName should not be null.", communityName);
+        assertEquals("The name should match as expected", deviceKeySnmpName, communityName.name());
+    }
+}