Remove FreeMarker/Velocity/TilesConfigurer MVC config

After some further discussion:

The MVC config simplifies ViewResolver configuration especially where
content negotiation view resolution is involved.

The configuration of the underlying view technology however is kept
completely separate. In the case of the MVC namespace, dedicated
top-level freemarker, velocity, and tiles namespace elements are
provided. In the case of the MVC Java config, applications simply
declare FreeMarkerConfigurer, VelocityConfigurer, or TilesConfigurer
beans respectively.

Issue: SPR-7093

Author: rstoyanchev

spring-test/src/test/java/org/springframework/test/web/servlet/samples/context/JavaConfigTests.java

@@ -51,7 +51,7 @@
  * @author Sebastien Deleuze
  */
 @RunWith(SpringJUnit4ClassRunner.class)
-@WebAppConfiguration("src/test/resources/META-INF/web-resources")
+@WebAppConfiguration("classpath:META-INF/web-resources")
 @ContextHierarchy({
 	@ContextConfiguration(classes = RootConfig.class),
 	@ContextConfiguration(classes = WebConfig.class)
@@ -100,7 +100,7 @@ public PersonDao personDao() {
 
 	@Configuration
 	@EnableWebMvc
-	static class WebConfig extends WebMvcConfigurerAdapter implements TilesWebMvcConfigurer {
+	static class WebConfig extends WebMvcConfigurerAdapter {
 
 		@Autowired
 		private RootConfig rootConfig;
@@ -130,9 +130,11 @@ public void configureViewResolvers(ViewResolverRegistry registry) {
 			registry.tiles();
 		}
 
-		@Override
-		public void configureTiles(TilesConfigurer configurer) {
+		@Bean
+		public TilesConfigurer tilesConfigurer() {
+			TilesConfigurer configurer = new TilesConfigurer();
 			configurer.setDefinitions("/WEB-INF/**/tiles.xml");
+			return configurer;
 		}
 	}
 

spring-webmvc/src/main/java/org/springframework/web/servlet/config/annotation/EnableWebMvc.java

@@ -33,10 +33,6 @@
  * }
  * </pre>
  *
- * <p>As of 4.1 this annotation may also import {@link WebMvcFreeMarkerConfiguration},
- * {@link WebMvcVelocityConfiguration}, or {@link WebMvcTilesConfiguration} if
- * those libraries are found on the classpath.
- *
  * <p>To customize the imported configuration, implement the interface
  * {@link WebMvcConfigurer} or more likely extend the empty method base class
  * {@link WebMvcConfigurerAdapter} and override individual methods, e.g.:
@@ -61,10 +57,6 @@
  * }
  * </pre>
  *
- * <p>To customize the FreeMarker, Velocity, or Tiles configuration, additionally
- * implement {@link FreeMarkerWebMvcConfigurer}, {@link VelocityWebMvcConfigurer},
- * and/or {@link TilesWebMvcConfigurer}.
- *
  * <p>If {@link WebMvcConfigurer} does not expose some advanced setting that
  * needs to be configured, consider removing the {@code @EnableWebMvc}
  * annotation and extending directly from {@link WebMvcConfigurationSupport}, e.g.:
@@ -87,23 +79,15 @@
  * }
  * </pre>
  *
- * <p>When the {@code @EnableWebMvc} annotation is removed, the FreeMarker,
- * Velocity, and Tiles configuration is no longer automatically imported and need
- * to be imported explicitly.
- *
  * @author Dave Syer
  * @author Rossen Stoyanchev
- * @author Sebastien Deleuze
  * @since 3.1
  * @see org.springframework.web.servlet.config.annotation.WebMvcConfigurer
  * @see org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter
- * @see org.springframework.web.servlet.config.annotation.FreeMarkerWebMvcConfigurer
- * @see org.springframework.web.servlet.config.annotation.VelocityWebMvcConfigurer
- * @see org.springframework.web.servlet.config.annotation.TilesWebMvcConfigurer
  */
 @Retention(RetentionPolicy.RUNTIME)
 @Target(ElementType.TYPE)
 @Documented
-@Import({DelegatingWebMvcConfiguration.class, ViewConfigurationImportSelector.class})
+@Import({DelegatingWebMvcConfiguration.class})
 public @interface EnableWebMvc {
 }

spring-webmvc/src/main/java/org/springframework/web/servlet/config/annotation/FreeMarkerWebMvcConfigurer.java

@@ -130,28 +130,27 @@ private void initContentNegotiatingViewResolver(View[] defaultViews) {
 	}
 
 	/**
-	 * Enable view resolution by forwarding to JSP pages with a default view name
-	 * prefix of "/WEB-INF/" and a default suffix of ".jsp".
+	 * Register JSP view resolver using a default view name prefix of "/WEB-INF/"
+	 * and a default suffix of ".jsp".
 	 *
-	 * <p>This method may be invoked multiple and each call will register a
-	 * separate ViewResolver instance. Note that since it's not easy to determine
+	 * <p>When this method is invoked more than once, each call will register a
+	 * new ViewResolver instance. Note that since it's not easy to determine
 	 * if a JSP exists without forwarding to it, using multiple JSP-based view
 	 * resolvers only makes sense in combination with the "viewNames" property
-	 * that indicates which view names are handled by which resolver.
+	 * on the resolver indicating which view names are handled by which resolver.
 	 */
 	public UrlBasedViewResolverRegistration jsp() {
 		return jsp("/WEB-INF/", ".jsp");
 	}
 
 	/**
-	 * Enable view resolution by forwarding to JSP pages with the specified
-	 * prefix and suffix.
+	 * Register JSP view resolver with the specified prefix and suffix.
 	 *
-	 * <p>This method may be invoked multiple and each call will register a
-	 * separate ViewResolver instance. Note that since it's not easy to determine
+	 * <p>When this method is invoked more than once, each call will register a
+	 * new ViewResolver instance. Note that since it's not easy to determine
 	 * if a JSP exists without forwarding to it, using multiple JSP-based view
 	 * resolvers only makes sense in combination with the "viewNames" property
-	 * that indicates which view names are handled by which resolver.
+	 * on the resolver indicating which view names are handled by which resolver.
 	 */
 	public UrlBasedViewResolverRegistration jsp(String prefix, String suffix) {
 		InternalResourceViewResolver resolver = new InternalResourceViewResolver();
@@ -162,67 +161,63 @@ public UrlBasedViewResolverRegistration jsp(String prefix, String suffix) {
 	}
 
 	/**
-	 * Enable Tiles-based view resolution.
+	 * Register Tiles 3.x view resolver.
 	 *
-	 * <p>By default tiles definitions are expected to be in "/WEB-INF/tiles.xml".
-	 * To change that and other Tiles-related options please also implement the
-	 * interface {@link TilesWebMvcConfigurer}.
+	 * <p><strong>Note</strong> that you must also configure Tiles by adding a
+	 * {@link org.springframework.web.servlet.view.tiles3.TilesConfigurer} bean.
 	 */
 	public UrlBasedViewResolverRegistration tiles() {
 		if (this.applicationContext != null && !hasBeanOfType(TilesConfigurer.class)) {
-			throw new BeanInitializationException(
-					"It looks like you're trying to configure Tiles view resolution. " +
-					"If not using @EnableWebMvc you must import WebMvcTilesConfiguration, " +
-					"or declare your own TilesConfigurer bean.");
+			throw new BeanInitializationException("In addition to a Tiles view resolver " +
+					"there must also be a single TilesConfigurer bean in this web application context " +
+					"(or its parent).");
 		}
 		TilesRegistration registration = new TilesRegistration();
 		this.viewResolvers.add(registration.getViewResolver());
 		return registration;
 	}
 
 	/**
-	 * Enable FreeMarker-based view resolution with an empty default view name
+	 * Register a FreeMarker view resolver with an empty default view name
 	 * prefix and a default suffix of ".ftl".
 	 *
-	 * <p>By default the FreeMarker template loader path is set to "/WEB-INF/".
-	 * To change that and other FreeMarker-related options please also implement
-	 * the interface {@link FreeMarkerWebMvcConfigurer}.
+	 * <p><strong>Note</strong> that you must also configure FreeMarker by adding a
+	 * {@link org.springframework.web.servlet.view.freemarker.FreeMarkerConfigurer} bean.
 	 */
 	public UrlBasedViewResolverRegistration freeMarker() {
 		if (this.applicationContext != null && !hasBeanOfType(FreeMarkerConfigurer.class)) {
-			throw new BeanInitializationException(
-					"It looks like you're trying to configure FreeMarker view resolution. " +
-							"If not using @EnableWebMvc you must import WebMvcFreeMarkerConfiguration, " +
-							"or declare your own FreeMarkerConfigurer bean.");
+			throw new BeanInitializationException("In addition to a FreeMarker view resolver " +
+					"there must also be a single FreeMarkerConfig bean in this web application context " +
+					"(or its parent): FreeMarkerConfigurer is the usual implementation. " +
+					"This bean may be given any name.");
 		}
 		FreeMarkerRegistration registration = new FreeMarkerRegistration();
 		this.viewResolvers.add(registration.getViewResolver());
 		return registration;
 	}
 
 	/**
-	 * Enable Velocity-based view resolution with an empty default view name
+	 * Register Velocity view resolver with an empty default view name
 	 * prefix, a default suffix of ".vm".
 	 *
-	 * <p>By default the Velocity resource loader path is set to "/WEB-INF/".
-	 * To change that and other Velocity-related options please also implement
-	 * the interface {@link VelocityWebMvcConfigurer}.
+	 * <p><strong>Note</strong> that you must also configure Velocity by adding a
+	 * {@link org.springframework.web.servlet.view.velocity.VelocityConfigurer} bean.
 	 */
 	public UrlBasedViewResolverRegistration velocity() {
 		if (this.applicationContext != null && !hasBeanOfType(VelocityConfigurer.class)) {
-			throw new BeanInitializationException(
-					"It looks like you're trying to configure Velocity view resolution. " +
-					"If not using @EnableWebMvc you must import WebMvcVelocityConfiguration, " +
-					"or declare your own VelocityConfigurer bean.");
+			throw new BeanInitializationException("In addition to a Velocity view resolver " +
+					"there must also be a single VelocityConfig bean in this web application context " +
+					"(or its parent): VelocityConfigurer is the usual implementation. " +
+					"This bean may be given any name.");
 		}
 		VelocityRegistration registration = new VelocityRegistration();
 		this.viewResolvers.add(registration.getViewResolver());
 		return registration;
 	}
 
 	/**
-	 * Enable the ability to map view names returned from controllers to
-	 * {@link org.springframework.web.servlet.View} beans.
+	 * Register a bean name view resolver that interprets view names as the names
+	 * of {@link org.springframework.web.servlet.View} beans.
 	 */
 	public void beanName() {
 		BeanNameViewResolver resolver = new BeanNameViewResolver();