[ONOS-2815]: add RouterInterface and RouterInterfaceTest

Change-Id: Ia1711581059d217543556e3668633039574be309
diff --git a/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/RouterInterface.java b/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/RouterInterface.java
new file mode 100644
index 0000000..5c37c30
--- /dev/null
+++ b/apps/vtn/vtnrsc/src/main/java/org/onosproject/vtnrsc/RouterInterface.java
@@ -0,0 +1,119 @@
+/*
+ * Copyright 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.vtnrsc;
+
+import static com.google.common.base.MoreObjects.toStringHelper;
+import static com.google.common.base.Preconditions.checkNotNull;
+
+import java.util.Objects;
+
+/**
+ * Representation of a Router interface.
+ */
+public final class RouterInterface {
+    private final SubnetId subnetId;
+    private final VirtualPortId portId;
+    private final RouterId routerId;
+    private final TenantId tenantId;
+
+    // Public construction is prohibited
+    private RouterInterface(SubnetId subnetId, VirtualPortId portId,
+                            RouterId routerId, TenantId tenantId) {
+        this.subnetId = checkNotNull(subnetId, "subnetId cannot be null");
+        this.portId = checkNotNull(portId, "portId cannot be null");
+        this.routerId = checkNotNull(routerId, "routerId cannot be null");
+        this.tenantId = checkNotNull(tenantId, "tenantId cannot be null");
+    }
+
+    /**
+     * Creates router interface object.
+     *
+     * @param subnetId subnet identifier
+     * @param portId port identifier
+     * @param routerId router identifier
+     * @param tenantId tenant identifier
+     * @return RouterInterface
+     */
+    public static RouterInterface routerInterface(SubnetId subnetId,
+                                                  VirtualPortId portId,
+                                                  RouterId routerId,
+                                                  TenantId tenantId) {
+        return new RouterInterface(subnetId, portId, routerId, tenantId);
+    }
+
+    /**
+     * Returns subnet identifier.
+     *
+     * @return subnetId the subnet identifier
+     */
+    public SubnetId subnetId() {
+        return subnetId;
+    }
+
+    /**
+     * Returns port identifier.
+     *
+     * @return portId the port identifier
+     */
+    public VirtualPortId portId() {
+        return portId;
+    }
+
+    /**
+     * Returns router identifier.
+     *
+     * @return routerId the router identifier
+     */
+    public RouterId routerId() {
+        return routerId;
+    }
+
+    /**
+     * Returns tenant identifier.
+     *
+     * @return tenantId the tenant identifier
+     */
+    public TenantId tenantId() {
+        return tenantId;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(subnetId, portId, routerId, tenantId);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj instanceof RouterInterface) {
+            final RouterInterface that = (RouterInterface) obj;
+            return Objects.equals(this.subnetId, that.subnetId)
+                    && Objects.equals(this.portId, that.portId)
+                    && Objects.equals(this.routerId, that.routerId)
+                    && Objects.equals(this.tenantId, that.tenantId);
+        }
+        return false;
+    }
+
+    @Override
+    public String toString() {
+        return toStringHelper(this).add("subnetId", subnetId)
+                .add("portId", portId).add("routerId", routerId)
+                .add("tenantId", tenantId).toString();
+    }
+}
diff --git a/apps/vtn/vtnrsc/src/test/java/org/onosproject/vtnrsc/router/RouterInterfaceTest.java b/apps/vtn/vtnrsc/src/test/java/org/onosproject/vtnrsc/router/RouterInterfaceTest.java
new file mode 100644
index 0000000..53ea037
--- /dev/null
+++ b/apps/vtn/vtnrsc/src/test/java/org/onosproject/vtnrsc/router/RouterInterfaceTest.java
@@ -0,0 +1,97 @@
+/*
+ * Copyright 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.vtnrsc.router;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.notNullValue;
+import static org.onlab.junit.ImmutableClassChecker.assertThatClassIsImmutable;
+
+import org.junit.Test;
+import org.onosproject.vtnrsc.RouterId;
+import org.onosproject.vtnrsc.RouterInterface;
+import org.onosproject.vtnrsc.SubnetId;
+import org.onosproject.vtnrsc.TenantId;
+import org.onosproject.vtnrsc.VirtualPortId;
+
+import com.google.common.testing.EqualsTester;
+
+/**
+ * Unit tests for RouterInterface class.
+ */
+public class RouterInterfaceTest {
+    private String tenantIdStr = "123";
+    private String virtualPortId = "1212";
+    private String routeIdStr1 = "1";
+    private String routeIdStr2 = "2";
+    private String subnetIdStr = "1234567";
+
+    /**
+     * Checks that the RouterInterface class is immutable.
+     */
+    @Test
+    public void testImmutability() {
+        assertThatClassIsImmutable(RouterInterface.class);
+    }
+
+    /**
+     * Checks the operation of equals().
+     */
+    @Test
+    public void testEquals() {
+        final TenantId tenantId = TenantId.tenantId(tenantIdStr);
+        final VirtualPortId portId = VirtualPortId.portId(virtualPortId);
+        final RouterId routerId1 = RouterId.valueOf(routeIdStr1);
+        final RouterId routerId2 = RouterId.valueOf(routeIdStr2);
+        final SubnetId subnet = SubnetId.subnetId(subnetIdStr);
+
+        RouterInterface ri1 = RouterInterface.routerInterface(subnet, portId,
+                                                              routerId1,
+                                                              tenantId);
+        RouterInterface ri2 = RouterInterface.routerInterface(subnet, portId,
+                                                              routerId1,
+                                                              tenantId);
+        RouterInterface ri3 = RouterInterface.routerInterface(subnet, portId,
+                                                              routerId2,
+                                                              tenantId);
+
+        new EqualsTester().addEqualityGroup(ri1, ri2).addEqualityGroup(ri3)
+                .testEquals();
+    }
+
+    /**
+     * Checks the construction of a RouterInterface object.
+     */
+    @Test
+    public void testConstruction() {
+        final TenantId tenantId = TenantId.tenantId(tenantIdStr);
+        final VirtualPortId portId = VirtualPortId.portId(virtualPortId);
+        final RouterId routerId1 = RouterId.valueOf(routeIdStr1);
+        final SubnetId subnet = SubnetId.subnetId(subnetIdStr);
+
+        RouterInterface ri1 = RouterInterface.routerInterface(subnet, portId,
+                                                              routerId1,
+                                                              tenantId);
+        assertThat(portId, is(notNullValue()));
+        assertThat(portId, is(ri1.portId()));
+        assertThat(tenantId, is(notNullValue()));
+        assertThat(tenantId, is(ri1.tenantId()));
+        assertThat(routerId1, is(notNullValue()));
+        assertThat(routerId1, is(ri1.routerId()));
+        assertThat(subnet, is(notNullValue()));
+        assertThat(subnet, is(ri1.subnetId()));
+    }
+}