AbstractCachingViewResolver caches unresolved view names by default ("cacheUnresolved"=true; SPR-8173)

Author: jhoeller

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/view/AbstractCachingViewResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2009 the original author or authors.
+ * Copyright 2002-2011 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.
@@ -42,8 +42,8 @@ public abstract class AbstractCachingViewResolver extends WebApplicationObjectSu
 	/** Whether we should cache views, once resolved */
 	private boolean cache = true;
 
-	/** Whether we should attempt to resolve views again if unresolved once */
-	private boolean cacheUnresolved = false;
+	/** Whether we should refrain from resolving views again if unresolved once */
+	private boolean cacheUnresolved = true;
 
 	/** Map from view key to View instance */
 	private final Map<Object, View> viewCache = new HashMap<Object, View>();
@@ -65,15 +65,17 @@ public void setCache(boolean cache) {
 	public boolean isCache() {
 		return this.cache;
 	}
-	
+
 	/**
-	 * Whether a view name once resolved to {@code null} should be cached and 
+	 * Whether a view name once resolved to {@code null} should be cached and
 	 * automatically resolved to {@code null} subsequently.
-	 * <p>Default is "false": unresolved view names are not cached.
-	 * <p>Of specific interest is the ability for some AbstractUrlBasedView 
-	 * implementations (Freemarker, Velocity, Tiles) to check if an underlying 
+	 * <p>Default is "true": unresolved view names are being cached, as of Spring 3.1.
+	 * Note that this flag only applies if the general {@link #setCache "cache"}
+	 * flag is kept at its default of "true" as well.
+	 * <p>Of specific interest is the ability for some AbstractUrlBasedView
+	 * implementations (FreeMarker, Velocity, Tiles) to check if an underlying
 	 * resource exists via {@link AbstractUrlBasedView#checkResource(Locale)}.
-	 * With this flag set to "false", an underlying resource that re-appears 
+	 * With this flag set to "false", an underlying resource that re-appears
 	 * is noticed and used. With the flag set to "true", one check is made only.
 	 */
 	public void setCacheUnresolved(boolean cacheUnresolved) {
@@ -84,9 +86,10 @@ public void setCacheUnresolved(boolean cacheUnresolved) {
 	 * Return if caching of unresolved views is enabled.
 	 */
 	public boolean isCacheUnresolved() {
-		return cacheUnresolved;
+		return this.cacheUnresolved;
 	}
 
+
 	public View resolveViewName(String viewName, Locale locale) throws Exception {
 		if (!isCache()) {
 			return createView(viewName, locale);
@@ -95,13 +98,14 @@ public View resolveViewName(String viewName, Locale locale) throws Exception {
 			Object cacheKey = getCacheKey(viewName, locale);
 			synchronized (this.viewCache) {
 				View view = this.viewCache.get(cacheKey);
-				boolean isCached = this.cacheUnresolved && this.viewCache.containsKey(cacheKey);
-				if (view == null && !isCached) {
+				if (view == null && (!this.cacheUnresolved || !this.viewCache.containsKey(cacheKey))) {
 					// Ask the subclass to create the View object.
 					view = createView(viewName, locale);
-					this.viewCache.put(cacheKey, view);
-					if (logger.isTraceEnabled()) {
-						logger.trace("Cached view [" + cacheKey + "]");
+					if (view != null || this.cacheUnresolved) {
+						this.viewCache.put(cacheKey, view);
+						if (logger.isTraceEnabled()) {
+							logger.trace("Cached view [" + cacheKey + "]");
+						}
 					}
 				}
 				return view;