Tiles 3 TilesViewResolver allows for specifying custom TilesView subclasses as well

Issue: SPR-12075
(cherry picked from commit 7c57424)

Author: jhoeller

spring-webmvc-tiles3/src/main/java/org/springframework/web/servlet/view/tiles3/TilesViewResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2012 the original author or authors.
+ * Copyright 2002-2014 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -13,9 +13,11 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.web.servlet.view.tiles3;
 
 import org.apache.tiles.request.render.Renderer;
+
 import org.springframework.web.servlet.view.UrlBasedViewResolver;
 
 /**
@@ -24,31 +26,43 @@
  *
  * @author Nicolas Le Bas
  * @author Rossen Stoyanchev
+ * @author Juergen Hoeller
  * @since 3.2
  */
 public class TilesViewResolver extends UrlBasedViewResolver {
 
 	private Renderer renderer;
 
 
+	public TilesViewResolver() {
+		setViewClass(requiredViewClass());
+	}
+
+
+	/**
+	 * Requires {@link TilesView}.
+	 */
 	@Override
-	protected Class<?> getViewClass() {
+	protected Class<?> requiredViewClass() {
 		return TilesView.class;
 	}
 
 	/**
-	 * Set the {@link Renderer} to use. If not set, by default
-	 * {@link org.apache.tiles.renderer.DefinitionRenderer} is used.
+	 * Set the {@link Renderer} to use. If not specified, a default
+	 * {@link org.apache.tiles.renderer.DefinitionRenderer} will be used.
 	 * @see TilesView#setRenderer(Renderer)
 	 */
 	public void setRenderer(Renderer renderer) {
 		this.renderer = renderer;
 	}
 
+
 	@Override
 	protected TilesView buildView(String viewName) throws Exception {
 		TilesView view = (TilesView) super.buildView(viewName);
-		view.setRenderer(this.renderer);
+		if (this.renderer != null) {
+			view.setRenderer(this.renderer);
+		}
 		return view;
 	}