Rename ResourcePath.Key to ResourceId for naming consistency

Change-Id: Idb34624f897b0fd5745f26758a007c171f4cd774
diff --git a/core/api/src/main/java/org/onosproject/net/newresource/ResourceId.java b/core/api/src/main/java/org/onosproject/net/newresource/ResourceId.java
new file mode 100644
index 0000000..f32579f
--- /dev/null
+++ b/core/api/src/main/java/org/onosproject/net/newresource/ResourceId.java
@@ -0,0 +1,102 @@
+/*
+ * 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.net.newresource;
+
+import com.google.common.annotations.Beta;
+import com.google.common.base.MoreObjects;
+import com.google.common.collect.ImmutableList;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.PortNumber;
+
+import java.util.Objects;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Represents identifier of resource.
+ * This class is exposed to public, but intended to use only in ResourceStore implementations.
+ */
+@Beta
+public final class ResourceId {
+    static final ResourceId ROOT = new ResourceId();
+
+    final ImmutableList<Object> components;
+
+    static ResourceId of(DeviceId device, Object... components) {
+        return new ResourceId(ImmutableList.builder()
+                .add(device)
+                .add(components)
+                .build());
+    }
+
+    static ResourceId of(DeviceId device, PortNumber port, Object... components) {
+        return new ResourceId(ImmutableList.builder()
+                .add(device)
+                .add(port)
+                .add(components)
+                .build());
+    }
+
+    private ResourceId(ImmutableList<Object> components) {
+        this.components = checkNotNull(components);
+    }
+
+    // for serializer
+    private ResourceId() {
+        this.components = ImmutableList.of();
+    }
+
+    // IndexOutOfBoundsException is raised when the instance is equal to ROOT
+    ResourceId parent() {
+        if (components.size() == 1) {
+            return ROOT;
+        } else {
+            return new ResourceId(components.subList(0, components.size() - 1));
+        }
+    }
+
+    ResourceId child(Object child) {
+        return new ResourceId(ImmutableList.builder()
+                .add(components)
+                .add(child)
+                .build());
+    }
+
+    @Override
+    public int hashCode() {
+        return components.hashCode();
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof ResourceId)) {
+            return false;
+        }
+
+        ResourceId other = (ResourceId) obj;
+        return Objects.equals(this.components, other.components);
+    }
+
+    @Override
+    public String toString() {
+        return MoreObjects.toStringHelper(this)
+                .add("components", components)
+                .toString();
+    }
+}