domain intent APIs

Change-Id: I4b2ac854da7808a880ef0a37b3b08ef51da812e5
diff --git a/core/api/src/main/java/org/onosproject/net/domain/DomainId.java b/core/api/src/main/java/org/onosproject/net/domain/DomainId.java
new file mode 100644
index 0000000..6c67009
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/domain/DomainId.java
@@ -0,0 +1,49 @@
+/*
+ * Copyright 2016-present 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.net.domain;
+
+import org.onlab.util.Identifier;
+
+/**
+ * Representation of a domain identity.
+ */
+public class DomainId extends Identifier<String> {
+
+    /**
+     * Represents the domain directly managed by ONOS.
+     */
+    public static final DomainId LOCAL = domainId("local");
+
+    /**
+     * Constructor of the peer id.
+     *
+     * @param identifier of the peer
+     */
+    public DomainId(String identifier) {
+        super(identifier);
+    }
+
+    /**
+     * Creates a peer id from the string identifier.
+     *
+     * @param identifier string identifier
+     * @return instance of the class DomainId
+     */
+    public static DomainId domainId(String identifier) {
+        return new DomainId(identifier);
+    }
+}