diff --git a/framework/src/play/mvc/ActionInvoker.java b/framework/src/play/mvc/ActionInvoker.java
index df3cbc35..b5596d06 100644
--- a/framework/src/play/mvc/ActionInvoker.java
+++ b/framework/src/play/mvc/ActionInvoker.java
@@ -130,7 +130,7 @@ public void invoke(Http.Request request, Http.Response response) {
                 // Check the cache (only for GET or HEAD)
                 if ((request.method.equals("GET") || request.method.equals("HEAD")) && actionMethod.isAnnotationPresent(CacheFor.class)) {
                     cacheKey = actionMethod.getAnnotation(CacheFor.class).id();
-                    if ("".equals(cacheKey)) {
+                    if (cacheKey != null && cacheKey.isEmpty()) {
                         cacheKey = "urlcache:" + request.path + '?' + request.querystring;
                     }
                     actionResult = Cache.get(cacheKey);
@@ -184,8 +184,8 @@ boolean actionNeedsSession(Http.Request request) {
 
     private PlayController createController(ActionContext context) {
         PlayController controller = Injector.getBeanOfType(context.request.controllerClass);
-        if (controller instanceof Controller) {
-          ((Controller) controller).setContext(context);
+        if (controller instanceof PlayContextController) {
+          ((PlayContextController) controller).setContext(context);
         }
         return controller;
     }
@@ -403,7 +403,6 @@ static void handleFinallies(Http.Request request, Session session, Throwable cau
         }
     }
 
-    @SuppressWarnings("unchecked")
     public static void inferResult(Object o) {
         // Return type inference
         if (o != null) {
@@ -468,8 +467,8 @@ public static Object[] getActionMethod(String fullAction) {
             if (!fullAction.startsWith("controllers.")) {
                 fullAction = "controllers." + fullAction;
             }
-            String controller = fullAction.substring(0, fullAction.lastIndexOf("."));
-            String action = fullAction.substring(fullAction.lastIndexOf(".") + 1);
+            String controller = fullAction.substring(0, fullAction.lastIndexOf('.'));
+            String action = fullAction.substring(fullAction.lastIndexOf('.') + 1);
             controllerClass = Play.classes.getClassIgnoreCase(controller);
             if (controllerClass == null) {
                 throw new ActionNotFoundException(fullAction, new Exception("Controller " + controller + " not found"));
diff --git a/framework/src/play/mvc/Controller.java b/framework/src/play/mvc/Controller.java
index 0410657b..0ddc76b1 100644
--- a/framework/src/play/mvc/Controller.java
+++ b/framework/src/play/mvc/Controller.java
@@ -5,7 +5,7 @@
 import play.mvc.results.Forbidden;
 import play.rebel.View;
 
-public class Controller implements PlayController {
+public class Controller implements PlayContextController {
   protected ActionContext actionContext;
   protected Http.Request request;
   protected Http.Response response;
@@ -15,7 +15,7 @@ public class Controller implements PlayController {
   protected Scope.RenderArgs renderArgs;
   protected Validation validation;
 
-  protected void setContext(ActionContext actionContext) {
+  public void setContext(ActionContext actionContext) {
     this.actionContext = actionContext;
     request = actionContext.request;
     response = actionContext.response;
diff --git a/framework/src/play/mvc/PlayContextController.java b/framework/src/play/mvc/PlayContextController.java
new file mode 100644
index 00000000..93feae7c
--- /dev/null
+++ b/framework/src/play/mvc/PlayContextController.java
@@ -0,0 +1,12 @@
+package play.mvc;
+
+/**
+ * Interface for play controllers with ActionContext provided to them by the {@link play.mvc.ActionInvoker}.
+ * 
+ * This class your controllers should implement, when they need access to the {@link play.mvc.ActionContext}.
+ * In most cases, you can extend {@link play.mvc.Controller} which provides a basic set of features
+ * useful when implementing controllers.
+ */
+public interface PlayContextController extends PlayController {
+  void setContext(ActionContext actionContext);
+}
diff --git a/framework/src/play/mvc/PlayController.java b/framework/src/play/mvc/PlayController.java
index 69d70296..0a512959 100644
--- a/framework/src/play/mvc/PlayController.java
+++ b/framework/src/play/mvc/PlayController.java
@@ -3,8 +3,8 @@
 /**
  * Marker interface for play controllers
  * 
- * This is the class that your controllers should implement.
- * In most cases, you can extend play.mvc.Controller that contains all needed methods for controllers.
+ * This is the class that your controllers should implement when they need very few capabilities..
+ * In most cases, you can extend {@link play.mvc.Controller} which provides a basic set of features for controllers.
  */
 public interface PlayController {
 }