Velocity/FreeMarker/TilesViewResolver only return a view if the target resource exists now

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2008 the original author or authors.
+ * Copyright 2002-2009 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.
@@ -66,7 +66,6 @@ public abstract class AbstractCachingViewResolver extends WebApplicationObjectSu
 
 	public View resolveViewName(String viewName, Locale locale) throws Exception {
 		if (!isCache()) {
-			logger.warn("View caching is SWITCHED OFF -- DEVELOPMENT SETTING ONLY: This can severely impair performance");
 			return createView(viewName, locale);
 		}
 		else {
@@ -112,7 +111,7 @@ public abstract class AbstractCachingViewResolver extends WebApplicationObjectSu
 		}
 		else {
 			Object cacheKey = getCacheKey(viewName, locale);
-			Object cachedView = null;
+			Object cachedView;
 			synchronized (this.viewCache) {
 				cachedView = this.viewCache.remove(cacheKey);
 			}

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2008 the original author or authors.
+ * Copyright 2002-2009 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.
@@ -75,6 +75,16 @@ public abstract class AbstractUrlBasedView extends AbstractView implements Initi
 		return true;
 	}
 
+	/**
+	 * Check whether the underlying resource that the configured URL points to
+	 * actually exists.
+	 * @return <code>true</code> if the resource exists (or is assumed to exist);
+	 * <code>false</code> if we know that it does not exist
+	 * @throws Exception if the resource exists but is invalid (e.g. could not be parsed)
+	 */
+	public boolean checkResource() throws Exception {
+		return true;
+	}
 
 	@Override
 	public String toString() {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2008 the original author or authors.
+ * Copyright 2002-2009 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.
@@ -61,9 +61,12 @@ import org.springframework.web.servlet.View;
  * <p>Note: This class does not support localized resolution, i.e. resolving
  * a symbolic view name to different resources depending on the current locale.
  *
- * <p>Note: When chaining ViewResolvers, a UrlBasedViewResolver always needs
- * to be last, as it will attempt to resolve any view name, no matter whether
- * the underlying resource actually exists.
+ * <p><b>Note:</b> When chaining ViewResolvers, a UrlBasedViewResolver will check whether
+ * the {@link AbstractUrlBasedView#checkResource specified resource actually exists}.
+ * However, with {@link InternalResourceView}, it is not generally possible to
+ * determine the existence of the target resource upfront. In such a scenario,
+ * a UrlBasedViewResolver will always return View for any given view name;
+ * as a consequence, it should be configured as the last ViewResolver in the chain.
  *
  * @author Juergen Hoeller
  * @author Rob Harrop
@@ -370,8 +373,7 @@ public class UrlBasedViewResolver extends AbstractCachingViewResolver implements
 		// Check for special "redirect:" prefix.
 		if (viewName.startsWith(REDIRECT_URL_PREFIX)) {
 			String redirectUrl = viewName.substring(REDIRECT_URL_PREFIX.length());
-			return new RedirectView(
-							redirectUrl, isRedirectContextRelative(), isRedirectHttp10Compatible());
+			return new RedirectView(redirectUrl, isRedirectContextRelative(), isRedirectHttp10Compatible());
 		}
 		// Check for special "forward:" prefix.
 		if (viewName.startsWith(FORWARD_URL_PREFIX)) {
@@ -415,7 +417,8 @@ public class UrlBasedViewResolver extends AbstractCachingViewResolver implements
 	@Override
 	protected View loadView(String viewName, Locale locale) throws Exception {
 		AbstractUrlBasedView view = buildView(viewName);
-		return (View) getApplicationContext().getAutowireCapableBeanFactory().initializeBean(view, viewName);
+		View result = (View) getApplicationContext().getAutowireCapableBeanFactory().initializeBean(view, viewName);
+		return (view.checkResource() ? result : null);
 	}
 
 	/**

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/view/freemarker/FreeMarkerConfig.java

@@ -1,12 +1,12 @@
 /*
- * Copyright 2002-2005 the original author or authors.
- * 
+ * Copyright 2002-2009 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.
  * 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.
@@ -22,7 +22,7 @@ import freemarker.ext.jsp.TaglibFactory;
 /**
  * Interface to be implemented by objects that configure and manage a
  * FreeMarker Configuration object in a web environment. Detected and
- * used by FreeMarkerView.
+ * used by {@link FreeMarkerView}.
  *
  * @author Darren Davison
  * @author Rob Harrop

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/view/freemarker/FreeMarkerConfigurer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2006 the original author or authors.
+ * Copyright 2002-2009 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.
@@ -18,10 +18,10 @@ package org.springframework.web.servlet.view.freemarker;
 
 import java.io.IOException;
 import java.util.List;
-
 import javax.servlet.ServletContext;
 
 import freemarker.cache.ClassTemplateLoader;
+import freemarker.cache.TemplateLoader;
 import freemarker.ext.jsp.TaglibFactory;
 import freemarker.template.Configuration;
 import freemarker.template.TemplateException;
@@ -120,7 +120,7 @@ public class FreeMarkerConfigurer extends FreeMarkerConfigurationFactory
 	 * for the Spring-provided macros, added to the end of the list.
 	 */
 	@Override
-	protected void postProcessTemplateLoaders(List templateLoaders) {
+	protected void postProcessTemplateLoaders(List<TemplateLoader> templateLoaders) {
 		templateLoaders.add(new ClassTemplateLoader(FreeMarkerConfigurer.class, ""));
 		logger.info("ClassTemplateLoader for Spring macros added to FreeMarker configuration");
 	}

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/view/freemarker/FreeMarkerView.java

@@ -16,6 +16,7 @@
 
 package org.springframework.web.servlet.view.freemarker;
 
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.util.Collections;
 import java.util.Enumeration;
@@ -112,7 +113,7 @@ public class FreeMarkerView extends AbstractTemplateView {
 
 	/**
 	 * Set the FreeMarker Configuration to be used by this view.
-	 * If this is not set, the default lookup will occur: a single {@link FreeMarkerConfig}
+	 * <p>If this is not set, the default lookup will occur: a single {@link FreeMarkerConfig}
 	 * is expected in the current web application context, with any bean name.
 	 * <strong>Note:</strong> using this method will cause a new instance of {@link TaglibFactory}
 	 * to created for every single {@link FreeMarkerView} instance. This can be quite expensive
@@ -158,8 +159,6 @@ public class FreeMarkerView extends AbstractTemplateView {
 			throw new BeanInitializationException("Initialization of GenericServlet adapter failed", ex);
 		}
 		this.servletContextHashModel = new ServletContextHashModel(servlet, getObjectWrapper());
-
-		checkTemplate();
 	}
 
 	/**
@@ -196,12 +195,19 @@ public class FreeMarkerView extends AbstractTemplateView {
 	 * Check that the FreeMarker template used for this view exists and is valid.
 	 * <p>Can be overridden to customize the behavior, for example in case of
 	 * multiple templates to be rendered into a single view.
-	 * @throws ApplicationContextException if the template cannot be found or is invalid
 	 */
-	protected void checkTemplate() throws ApplicationContextException {
+	@Override
+	public boolean checkResource() throws Exception {
 		try {
 			// Check that we can get the template, even if we might subsequently get it again.
-			getTemplate(getConfiguration().getLocale());
+			getTemplate(getUrl(), getConfiguration().getLocale());
+			return true;
+		}
+		catch (FileNotFoundException ex) {
+			if (logger.isDebugEnabled()) {
+				logger.debug("No FreeMarker view found for URL: " + getUrl());
+			}
+			return false;
 		}
 		catch (ParseException ex) {
 			throw new ApplicationContextException(

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/view/freemarker/FreeMarkerViewResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2006 the original author or authors.
+ * Copyright 2002-2009 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.
@@ -19,15 +19,15 @@ package org.springframework.web.servlet.view.freemarker;
 import org.springframework.web.servlet.view.AbstractTemplateViewResolver;
 
 /**
- * Convenience subclass of UrlBasedViewResolver that supports FreeMarkerView
- * (i.e. FreeMarker templates) and custom subclasses of it.
+ * Convenience subclass of {@link org.springframework.web.servlet.view.UrlBasedViewResolver}
+ * that supports {@link FreeMarkerView} (i.e. FreeMarker templates) and custom subclasses of it.
  *
  * <p>The view class for all views generated by this resolver can be specified
- * via <code>setViewClass</code>. See UrlBasedViewResolver's javadoc for details.
+ * via the "viewClass" property. See UrlBasedViewResolver's javadoc for details.
  *
- * <p><b>Note:</b> When chaining ViewResolvers, a FreeMarkerViewResolver always
- * needs to be last, as it will attempt to resolve any view name, no matter
- * whether the underlying resource actually exists.
+ * <p><b>Note:</b> When chaining ViewResolvers, a FreeMarkerViewResolver will
+ * check for the existence of the specified template resources and only return
+ * a non-null View object if the template was actually found.
  *
  * @author Juergen Hoeller
  * @since 1.1
@@ -40,18 +40,12 @@ import org.springframework.web.servlet.view.AbstractTemplateViewResolver;
  */
 public class FreeMarkerViewResolver extends AbstractTemplateViewResolver {
 
-	/**
-	 * Sets default viewClass to <code>requiredViewClass</code>.
-	 * @see #setViewClass
-	 * @see #requiredViewClass
-	 */
 	public FreeMarkerViewResolver() {
 		setViewClass(requiredViewClass());
 	}
 
 	/**
-	 * Requires FreeMarkerView.
-	 * @see FreeMarkerView
+	 * Requires {@link FreeMarkerView}.
 	 */
 	@Override
 	protected Class requiredViewClass() {

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/view/tiles2/TilesConfigurer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2007 the original author or authors.
+ * Copyright 2002-2009 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.
@@ -18,7 +18,6 @@ package org.springframework.web.servlet.view.tiles2;
 
 import java.util.Enumeration;
 import java.util.Properties;
-
 import javax.servlet.ServletConfig;
 import javax.servlet.ServletContext;
 
@@ -49,14 +48,11 @@ import org.springframework.web.context.ServletContextAware;
  * for more information about Tiles, which basically is a templating
  * mechanism for JSP-based web applications.
  *
- * <p>The TilesConfigurer simply configures a TilesContainer using a set
- * of files containing definitions, to be accessed by {@link TilesView}
- * instances.
+ * <p>The TilesConfigurer simply configures a TilesContainer using a set of files
+ * containing definitions, to be accessed by {@link TilesView} instances.
  *
  * <p>TilesViews can be managed by any {@link org.springframework.web.servlet.ViewResolver}.
- * For simple convention-based view resolution, consider using
- * {@link org.springframework.web.servlet.view.UrlBasedViewResolver} with the
- * "viewClass" property set to "org.springframework.web.servlet.view.tiles2.TilesView".
+ * For simple convention-based view resolution, consider using {@link TilesViewResolver}.
  *
  * <p>A typical TilesConfigurer bean definition looks as follows:
  *

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/view/tiles2/TilesView.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2008 the original author or authors.
+ * Copyright 2002-2009 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.
@@ -17,7 +17,6 @@
 package org.springframework.web.servlet.view.tiles2;
 
 import java.util.Map;
-
 import javax.servlet.ServletContext;
 import javax.servlet.ServletException;
 import javax.servlet.http.HttpServletRequest;
@@ -49,6 +48,12 @@ import org.springframework.web.util.WebUtils;
  */
 public class TilesView extends AbstractUrlBasedView {
 
+	@Override
+	public boolean checkResource() throws Exception {
+		TilesContainer container = TilesAccess.getContainer(getServletContext());
+		return container.isValidDefinition(getUrl());
+	}
+
 	@Override
 	protected void renderMergedOutputModel(
 			Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception {

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/view/tiles2/TilesViewResolver.java

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2002-2009 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.
+ * 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.springframework.web.servlet.view.tiles2;
+
+import org.springframework.web.servlet.view.UrlBasedViewResolver;
+
+/**
+ * Convenience subclass of {@link org.springframework.web.servlet.view.UrlBasedViewResolver}
+ * that supports {@link TilesView} (i.e. Tiles definitions) and custom subclasses of it.
+ *
+ * <p>The view class for all views generated by this resolver can be specified
+ * via the "viewClass" property. See UrlBasedViewResolver's javadoc for details.
+ *
+ * <p><b>Note:</b> When chaining ViewResolvers, a TilesViewResolver will
+ * check for the existence of the specified template resources and only return
+ * a non-null View object if the template was actually found.
+ *
+ * @author Juergen Hoeller
+ * @since 3.0
+ * @see #setViewClass
+ * @see #setPrefix
+ * @see #setSuffix
+ * @see #setRequestContextAttribute
+ * @see TilesView
+ */
+public class TilesViewResolver extends UrlBasedViewResolver {
+
+	public TilesViewResolver() {
+		setViewClass(requiredViewClass());
+	}
+
+	/**
+	 * Requires {@link TilesView}.
+	 */
+	@Override
+	protected Class requiredViewClass() {
+		return TilesView.class;
+	}
+
+}

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/view/velocity/VelocityLayoutView.java

@@ -17,14 +17,13 @@
 package org.springframework.web.servlet.view.velocity;
 
 import java.io.StringWriter;
-
 import javax.servlet.http.HttpServletResponse;
 
 import org.apache.velocity.Template;
 import org.apache.velocity.context.Context;
 import org.apache.velocity.exception.ResourceNotFoundException;
 
-import org.springframework.context.ApplicationContextException;
+import org.springframework.core.NestedIOException;
 
 /**
  * VelocityLayoutView emulates the functionality offered by Velocity's
@@ -119,19 +118,22 @@ public class VelocityLayoutView extends VelocityToolboxView {
 	 * can be changed which may invalidate any early checking done here.
 	 */
 	@Override
-	protected void checkTemplate() throws ApplicationContextException {
-		super.checkTemplate();
+	public boolean checkResource() throws Exception {
+		if (!super.checkResource()) {
+			return false;
+		}
 
 		try {
 			// Check that we can get the template, even if we might subsequently get it again.
 			getTemplate(this.layoutUrl);
+			return true;
 		}
 		catch (ResourceNotFoundException ex) {
-			throw new ApplicationContextException("Cannot find Velocity template for URL [" + this.layoutUrl +
+			throw new NestedIOException("Cannot find Velocity template for URL [" + this.layoutUrl +
 					"]: Did you specify the correct resource loader path?", ex);
 		}
 		catch (Exception ex) {
-			throw new ApplicationContextException(
+			throw new NestedIOException(
 					"Could not load Velocity template for URL [" + this.layoutUrl + "]", ex);
 		}
 	}

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/view/velocity/VelocityView.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2008 the original author or authors.
+ * Copyright 2002-2009 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.
@@ -34,6 +34,7 @@ import org.springframework.beans.BeansException;
 import org.springframework.beans.factory.BeanFactoryUtils;
 import org.springframework.beans.factory.NoSuchBeanDefinitionException;
 import org.springframework.context.ApplicationContextException;
+import org.springframework.core.NestedIOException;
 import org.springframework.web.servlet.support.RequestContextUtils;
 import org.springframework.web.servlet.view.AbstractTemplateView;
 import org.springframework.web.util.NestedServletException;
@@ -52,10 +53,10 @@ import org.springframework.web.util.NestedServletException;
  * view, or <code>null</code> if not needed. VelocityFormatter is part of standard Velocity.
  * <li><b>dateToolAttribute</b> (optional, default=null): the name of the
  * DateTool helper object to expose in the Velocity context of this view,
- * or <code>null</code> if not needed. DateTool is part of Velocity Tools 1.0.
+ * or <code>null</code> if not needed. DateTool is part of Velocity Tools.
  * <li><b>numberToolAttribute</b> (optional, default=null): the name of the
  * NumberTool helper object to expose in the Velocity context of this view,
- * or <code>null</code> if not needed. NumberTool is part of Velocity Tools 1.1.
+ * or <code>null</code> if not needed. NumberTool is part of Velocity Tools.
  * <li><b>cacheTemplate</b> (optional, default=false): whether or not the Velocity
  * template should be cached. It should normally be true in production, but setting
  * this to false enables us to modify Velocity templates without restarting the
@@ -67,8 +68,8 @@ import org.springframework.web.util.NestedServletException;
  * accessible in the current web application context, with any bean name.
  * Alternatively, you can set the VelocityEngine object as bean property.
  *
- * <p>Note: Spring's VelocityView requires Velocity 1.3 or higher, and optionally
- * Velocity Tools 1.0 or higher (depending on the use of DateTool and/or NumberTool).
+ * <p>Note: Spring 3.0's VelocityView requires Velocity 1.4 or higher, and optionally
+ * Velocity Tools 1.1 or higher (depending on the use of DateTool and/or NumberTool).
  *
  * @author Rod Johnson
  * @author Juergen Hoeller
@@ -194,7 +195,7 @@ public class VelocityView extends AbstractTemplateView {
 
 	/**
 	 * Set the VelocityEngine to be used by this view.
-	 * If this is not set, the default lookup will occur: A single VelocityConfig
+	 * <p>If this is not set, the default lookup will occur: A single VelocityConfig
 	 * is expected in the current web application context, with any bean name.
 	 * @see VelocityConfig
 	 */
@@ -222,8 +223,6 @@ public class VelocityView extends AbstractTemplateView {
 			// No explicit VelocityEngine: try to autodetect one.
 			setVelocityEngine(autodetectVelocityEngine());
 		}
-
-		checkTemplate();
 	}
 
 	/**
@@ -252,19 +251,22 @@ public class VelocityView extends AbstractTemplateView {
 	 * Check that the Velocity template used for this view exists and is valid.
 	 * <p>Can be overridden to customize the behavior, for example in case of
 	 * multiple templates to be rendered into a single view.
-	 * @throws ApplicationContextException if the template cannot be found or is invalid
 	 */
-	protected void checkTemplate() throws ApplicationContextException {
+	@Override
+	public boolean checkResource() throws Exception {
 		try {
 			// Check that we can get the template, even if we might subsequently get it again.
-			this.template = getTemplate();
+			this.template = getTemplate(getUrl());
+			return true;
 		}
 		catch (ResourceNotFoundException ex) {
-			throw new ApplicationContextException("Cannot find Velocity template for URL [" + getUrl() +
-				"]: Did you specify the correct resource loader path?", ex);
+			if (logger.isDebugEnabled()) {
+				logger.debug("No Velocity view found for URL: " + getUrl());
+			}
+			return false;
 		}
 		catch (Exception ex) {
-			throw new ApplicationContextException(
+			throw new NestedIOException(
 					"Could not load Velocity template for URL [" + getUrl() + "]", ex);
 		}
 	}

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/view/velocity/VelocityViewResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2008 the original author or authors.
+ * Copyright 2002-2009 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.
@@ -21,14 +21,14 @@ import org.springframework.web.servlet.view.AbstractUrlBasedView;
 
 /**
  * Convenience subclass of {@link org.springframework.web.servlet.view.UrlBasedViewResolver}
- * that supports VelocityView (i.e. Velocity templates) and custom subclasses of it.
+ * that supports {@link VelocityView} (i.e. Velocity templates) and custom subclasses of it.
  *
  * <p>The view class for all views generated by this resolver can be specified
- * via <code>setViewClass</code>. See UrlBasedViewResolver's javadoc for details.
+ * via the "viewClass" property. See UrlBasedViewResolver's javadoc for details.
  *
- * <p><b>Note:</b> When chaining ViewResolvers, a VelocityViewResolver always needs
- * to be last, as it will attempt to resolve any view name, no matter whether
- * the underlying resource actually exists.
+ * <p><b>Note:</b> When chaining ViewResolvers, a VelocityViewResolver will
+ * check for the existence of the specified template resources and only return
+ * a non-null View object if the template was actually found.
  *
  * @author Juergen Hoeller
  * @since 13.12.2003
@@ -50,24 +50,19 @@ public class VelocityViewResolver extends AbstractTemplateViewResolver {
 	private String toolboxConfigLocation;
 
 
-	/**
-	 * Sets default viewClass to <code>requiredViewClass</code>.
-	 * @see #setViewClass
-	 * @see #requiredViewClass
-	 */
 	public VelocityViewResolver() {
 		setViewClass(requiredViewClass());
 	}
 
 	/**
-	 * Requires VelocityView.
-	 * @see VelocityView
+	 * Requires {@link VelocityView}.
 	 */
 	@Override
 	protected Class requiredViewClass() {
 		return VelocityView.class;
 	}
 
+
 	/**
 	 * Set the name of the DateTool helper object to expose in the Velocity context
 	 * of this view, or <code>null</code> if not needed. DateTool is part of Velocity Tools 1.0.