Define the new Intent Framework APIs (Intent Service)

- Define the base Intent class and sub-classes required in SDN-IP
- IntentService provides the APIs for application developers
- IntentExtensionService enables to define application specific intent types
- Provide event handling mechanism via IntentEventListener

This is for ONOS-1654.

Change-Id: Id1705f1fbc1acd4862b33fd9ab97aafe2e84a685
diff --git a/src/main/java/net/onrc/onos/api/newintent/IntentExtensionService.java b/src/main/java/net/onrc/onos/api/newintent/IntentExtensionService.java
new file mode 100644
index 0000000..1686e5f
--- /dev/null
+++ b/src/main/java/net/onrc/onos/api/newintent/IntentExtensionService.java
@@ -0,0 +1,57 @@
+package net.onrc.onos.api.newintent;
+
+import java.util.Map;
+
+/**
+ * Service for extending the capability of intent framework by
+ * adding additional compilers or/and installers.
+ */
+public interface IntentExtensionService {
+    /**
+     * Registers the specified compiler for the given intent class.
+     *
+     * @param cls intent class
+     * @param compiler intent compiler
+     * @param <T> the type of intent
+     */
+    <T extends Intent> void registerCompiler(Class<T> cls, IntentCompiler<T> compiler);
+
+    /**
+     * Unregisters the compiler for the specified intent class.
+     *
+     * @param cls intent class
+     * @param <T> the type of intent
+     */
+    <T extends Intent> void unregisterCompiler(Class<T> cls);
+
+    /**
+     * Returns immutable set of bindings of currently registered intent compilers.
+     *
+     * @return the set of compiler bindings
+     */
+    Map<Class<? extends Intent>, IntentCompiler<? extends Intent>> getCompilers();
+
+    /**
+     * Registers the specified installer for the given installable intent class.
+     *
+     * @param cls installable intent class
+     * @param installer intent installer
+     * @param <T> the type of installable intent
+     */
+    <T extends InstallableIntent> void registerInstaller(Class<T> cls, IntentInstaller<T> installer);
+
+    /**
+     * Unregisters the installer for the given installable intent class.
+     *
+     * @param cls installable intent class
+     * @param <T> the type of installable intent
+     */
+    <T extends InstallableIntent> void unregisterInstaller(Class<T> cls);
+
+    /**
+     * Returns immutable set of bindings of currently registered intent installers.
+     *
+     * @return the set of installer bindings
+     */
+    Map<Class<? extends InstallableIntent>, IntentInstaller<? extends InstallableIntent>> getInstallers();
+}