Completers for netcfg command

Change-Id: I925825f3ddb3ffde8fb59d8d0d4ccb9faf92fe37
diff --git a/cli/src/main/java/org/onosproject/cli/cfg/SubjectClassKeyCompleter.java b/cli/src/main/java/org/onosproject/cli/cfg/SubjectClassKeyCompleter.java
new file mode 100644
index 0000000..ad4f1b2
--- /dev/null
+++ b/cli/src/main/java/org/onosproject/cli/cfg/SubjectClassKeyCompleter.java
@@ -0,0 +1,41 @@
+/*
+ * 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.cli.cfg;
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.onosproject.cli.AbstractChoicesCompleter;
+import org.onosproject.cli.AbstractShellCommand;
+import org.onosproject.net.config.NetworkConfigRegistry;
+import org.onosproject.net.config.SubjectFactory;
+
+/**
+ * Network configuration subject class key completer.
+ */
+public class SubjectClassKeyCompleter extends AbstractChoicesCompleter {
+
+    @Override
+    protected List<String> choices() {
+        NetworkConfigRegistry service = AbstractShellCommand.get(NetworkConfigRegistry.class);
+        return service.getSubjectClasses()
+                .stream()
+                .map(service::getSubjectFactory)
+                .map(SubjectFactory::subjectClassKey)
+                .collect(Collectors.toList());
+    }
+
+}