Polishing

(cherry picked from commit 96f1a0e)

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

@@ -164,10 +164,10 @@ public class WebMvcConfigurationSupport implements ApplicationContextAware, Serv
 
 	private List<Object> interceptors;
 
-	private ContentNegotiationManager contentNegotiationManager;
-
 	private PathMatchConfigurer pathMatchConfigurer;
 
+	private ContentNegotiationManager contentNegotiationManager;
+
 	private List<HttpMessageConverter<?>> messageConverters;
 
 
@@ -186,6 +186,7 @@ public class WebMvcConfigurationSupport implements ApplicationContextAware, Serv
 		this.servletContext = servletContext;
 	}
 
+
 	/**
 	 * Return a {@link RequestMappingHandlerMapping} ordered at 0 for mapping
 	 * requests to annotated controllers.
@@ -207,11 +208,13 @@ public class WebMvcConfigurationSupport implements ApplicationContextAware, Serv
 		if (configurer.isUseTrailingSlashMatch() != null) {
 			handlerMapping.setUseTrailingSlashMatch(configurer.isUseTrailingSlashMatch());
 		}
-		if (configurer.getPathMatcher() != null) {
-			handlerMapping.setPathMatcher(configurer.getPathMatcher());
+		UrlPathHelper pathHelper = configurer.getUrlPathHelper();
+		if (pathHelper != null) {
+			handlerMapping.setUrlPathHelper(pathHelper);
 		}
-		if (configurer.getUrlPathHelper() != null) {
-			handlerMapping.setUrlPathHelper(configurer.getUrlPathHelper());
+		PathMatcher pathMatcher = configurer.getPathMatcher();
+		if (pathMatcher != null) {
+			handlerMapping.setPathMatcher(pathMatcher);
 		}
 
 		return handlerMapping;
@@ -240,48 +243,6 @@ public class WebMvcConfigurationSupport implements ApplicationContextAware, Serv
 	protected void addInterceptors(InterceptorRegistry registry) {
 	}
 
-	/**
-	 * Return a {@link ContentNegotiationManager} instance to use to determine
-	 * requested {@linkplain MediaType media types} in a given request.
-	 */
-	@Bean
-	public ContentNegotiationManager mvcContentNegotiationManager() {
-		if (this.contentNegotiationManager == null) {
-			ContentNegotiationConfigurer configurer = new ContentNegotiationConfigurer(this.servletContext);
-			configurer.mediaTypes(getDefaultMediaTypes());
-			configureContentNegotiation(configurer);
-			try {
-				this.contentNegotiationManager = configurer.getContentNegotiationManager();
-			}
-			catch (Exception ex) {
-				throw new BeanInitializationException("Could not create ContentNegotiationManager", ex);
-			}
-		}
-		return this.contentNegotiationManager;
-	}
-
-	protected Map<String, MediaType> getDefaultMediaTypes() {
-		Map<String, MediaType> map = new HashMap<String, MediaType>();
-		if (romePresent) {
-			map.put("atom", MediaType.APPLICATION_ATOM_XML);
-			map.put("rss", MediaType.valueOf("application/rss+xml"));
-		}
-		if (jaxb2Present) {
-			map.put("xml", MediaType.APPLICATION_XML);
-		}
-		if (jackson2Present || jacksonPresent) {
-			map.put("json", MediaType.APPLICATION_JSON);
-		}
-		return map;
-	}
-
-	/**
-	 * Override this method to configure content negotiation.
-	 * @see DefaultServletHandlerConfigurer
-	 */
-	protected void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
-	}
-
 	/**
 	 * Callback for building the {@link PathMatchConfigurer}.
 	 * Delegates to {@link #configurePathMatch}.
@@ -312,12 +273,8 @@ public class WebMvcConfigurationSupport implements ApplicationContextAware, Serv
 	 */
 	@Bean
 	public PathMatcher mvcPathMatcher() {
-		if (getPathMatchConfigurer().getPathMatcher() != null) {
-			return getPathMatchConfigurer().getPathMatcher();
-		}
-		else {
-			return new AntPathMatcher();
-		}
+		PathMatcher pathMatcher = getPathMatchConfigurer().getPathMatcher();
+		return (pathMatcher != null ? pathMatcher : new AntPathMatcher());
 	}
 
 	/**
@@ -329,12 +286,50 @@ public class WebMvcConfigurationSupport implements ApplicationContextAware, Serv
 	 */
 	@Bean
 	public UrlPathHelper mvcUrlPathHelper() {
-		if (getPathMatchConfigurer().getUrlPathHelper() != null) {
-			return getPathMatchConfigurer().getUrlPathHelper();
+		UrlPathHelper pathHelper = getPathMatchConfigurer().getUrlPathHelper();
+		return (pathHelper != null ? pathHelper : new UrlPathHelper());
+	}
+
+	/**
+	 * Return a {@link ContentNegotiationManager} instance to use to determine
+	 * requested {@linkplain MediaType media types} in a given request.
+	 */
+	@Bean
+	public ContentNegotiationManager mvcContentNegotiationManager() {
+		if (this.contentNegotiationManager == null) {
+			ContentNegotiationConfigurer configurer = new ContentNegotiationConfigurer(this.servletContext);
+			configurer.mediaTypes(getDefaultMediaTypes());
+			configureContentNegotiation(configurer);
+			try {
+				this.contentNegotiationManager = configurer.getContentNegotiationManager();
+			}
+			catch (Exception ex) {
+				throw new BeanInitializationException("Could not create ContentNegotiationManager", ex);
+			}
 		}
-		else {
-			return new UrlPathHelper();
+		return this.contentNegotiationManager;
+	}
+
+	protected Map<String, MediaType> getDefaultMediaTypes() {
+		Map<String, MediaType> map = new HashMap<String, MediaType>(4);
+		if (romePresent) {
+			map.put("atom", MediaType.APPLICATION_ATOM_XML);
+			map.put("rss", MediaType.valueOf("application/rss+xml"));
 		}
+		if (jaxb2Present) {
+			map.put("xml", MediaType.APPLICATION_XML);
+		}
+		if (jackson2Present || jacksonPresent) {
+			map.put("json", MediaType.APPLICATION_JSON);
+		}
+		return map;
+	}
+
+	/**
+	 * Override this method to configure content negotiation.
+	 * @see DefaultServletHandlerConfigurer
+	 */
+	protected void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
 	}
 
 	/**
@@ -450,7 +445,6 @@ public class WebMvcConfigurationSupport implements ApplicationContextAware, Serv
 
 		AsyncSupportConfigurer configurer = new AsyncSupportConfigurer();
 		configureAsyncSupport(configurer);
-
 		if (configurer.getTaskExecutor() != null) {
 			adapter.setTaskExecutor(configurer.getTaskExecutor());
 		}
@@ -475,6 +469,20 @@ public class WebMvcConfigurationSupport implements ApplicationContextAware, Serv
 		return initializer;
 	}
 
+	/**
+	 * Override this method to provide a custom {@link MessageCodesResolver}.
+	 */
+	protected MessageCodesResolver getMessageCodesResolver() {
+		return null;
+	}
+
+	/**
+	 * Override this method to configure asynchronous request processing options.
+	 * @see AsyncSupportConfigurer
+	 */
+	protected void configureAsyncSupport(AsyncSupportConfigurer configurer) {
+	}
+
 	/**
 	 * Return a {@link FormattingConversionService} for use with annotated
 	 * controller methods and the {@code spring:eval} JSP tag.
@@ -487,6 +495,12 @@ public class WebMvcConfigurationSupport implements ApplicationContextAware, Serv
 		return conversionService;
 	}
 
+	/**
+	 * Override this method to add custom {@link Converter}s and {@link Formatter}s.
+	 */
+	protected void addFormatters(FormatterRegistry registry) {
+	}
+
 	/**
 	 * Return a global {@link Validator} instance for example for validating
 	 * {@code @ModelAttribute} and {@code @RequestBody} method arguments.
@@ -511,7 +525,7 @@ public class WebMvcConfigurationSupport implements ApplicationContextAware, Serv
 				catch (LinkageError ex) {
 					throw new BeanInitializationException("Could not load default validator class", ex);
 				}
-				validator = (Validator) BeanUtils.instantiate(clazz);
+				validator = (Validator) BeanUtils.instantiateClass(clazz);
 			}
 			else {
 				validator = new NoOpValidator();
@@ -527,13 +541,6 @@ public class WebMvcConfigurationSupport implements ApplicationContextAware, Serv
 		return null;
 	}
 
-	/**
-	 * Override this method to provide a custom {@link MessageCodesResolver}.
-	 */
-	protected MessageCodesResolver getMessageCodesResolver() {
-		return null;
-	}
-
 	/**
 	 * Add custom {@link HandlerMethodArgumentResolver}s to use in addition to
 	 * the ones registered by default.
@@ -625,19 +632,6 @@ public class WebMvcConfigurationSupport implements ApplicationContextAware, Serv
 		}
 	}
 
-	/**
-	 * Override this method to add custom {@link Converter}s and {@link Formatter}s.
-	 */
-	protected void addFormatters(FormatterRegistry registry) {
-	}
-
-	/**
-	 * Override this method to configure asynchronous request processing options.
-	 * @see AsyncSupportConfigurer
-	 */
-	public void configureAsyncSupport(AsyncSupportConfigurer configurer) {
-	}
-
 	/**
 	 * Returns a {@link HttpRequestHandlerAdapter} for processing requests
 	 * with {@link HttpRequestHandler}s.
@@ -670,11 +664,9 @@ public class WebMvcConfigurationSupport implements ApplicationContextAware, Serv
 	public HandlerExceptionResolver handlerExceptionResolver() {
 		List<HandlerExceptionResolver> exceptionResolvers = new ArrayList<HandlerExceptionResolver>();
 		configureHandlerExceptionResolvers(exceptionResolvers);
-
 		if (exceptionResolvers.isEmpty()) {
 			addDefaultHandlerExceptionResolvers(exceptionResolvers);
 		}
-
 		HandlerExceptionResolverComposite composite = new HandlerExceptionResolverComposite();
 		composite.setOrder(0);
 		composite.setExceptionResolvers(exceptionResolvers);

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

@@ -61,14 +61,6 @@ public interface WebMvcConfigurer {
 	 */
 	void configureMessageConverters(List<HttpMessageConverter<?>> converters);
 
-	/**
-	 * Provide a custom {@link Validator} instead of the one created by default.
-	 * The default implementation, assuming JSR-303 is on the classpath, is:
-	 * {@link org.springframework.validation.beanvalidation.LocalValidatorFactoryBean}.
-	 * Leave the return value as {@code null} to keep the default.
-	 */
-	Validator getValidator();
-
 	/**
 	 * Configure content negotiation options.
 	 */
@@ -79,7 +71,6 @@ public interface WebMvcConfigurer {
 	 */
 	void configureAsyncSupport(AsyncSupportConfigurer configurer);
 
-
 	/**
 	 * Helps with configuring HandlerMappings path matching options such as trailing slash match,
 	 * suffix registration, path matcher and path helper.
@@ -126,13 +117,6 @@ public interface WebMvcConfigurer {
 	 */
 	void addInterceptors(InterceptorRegistry registry);
 
-	/**
-	 * Provide a custom {@link MessageCodesResolver} for building message codes
-	 * from data binding and validation error codes. Leave the return value as
-	 * {@code null} to keep the default.
-	 */
-	MessageCodesResolver getMessageCodesResolver();
-
 	/**
 	 * Add view controllers to create a direct mapping between a URL path and
 	 * view name without the need for a controller in between.
@@ -154,4 +138,19 @@ public interface WebMvcConfigurer {
 	 */
 	void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer);
 
+	/**
+	 * Provide a custom {@link Validator} instead of the one created by default.
+	 * The default implementation, assuming JSR-303 is on the classpath, is:
+	 * {@link org.springframework.validation.beanvalidation.LocalValidatorFactoryBean}.
+	 * Leave the return value as {@code null} to keep the default.
+	 */
+	Validator getValidator();
+
+	/**
+	 * Provide a custom {@link MessageCodesResolver} for building message codes
+	 * from data binding and validation error codes. Leave the return value as
+	 * {@code null} to keep the default.
+	 */
+	MessageCodesResolver getMessageCodesResolver();
+
 }

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

@@ -28,7 +28,7 @@ import org.springframework.web.servlet.HandlerExceptionResolver;
 
 /**
  * An implementation of {@link WebMvcConfigurer} with empty methods allowing
- * sub-classes to override only the methods they're interested in.
+ * subclasses to override only the methods they're interested in.
  *
  * @author Rossen Stoyanchev
  * @since 3.1
@@ -49,14 +49,6 @@ public abstract class WebMvcConfigurerAdapter implements WebMvcConfigurer {
 	public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
 	}
 
-	/**
-	 * {@inheritDoc}
-	 * <p>This implementation returns {@code null}
-	 */
-	public Validator getValidator() {
-		return null;
-	}
-
 	/**
 	 * {@inheritDoc}
 	 * <p>This implementation is empty.
@@ -99,14 +91,6 @@ public abstract class WebMvcConfigurerAdapter implements WebMvcConfigurer {
 	public void configureHandlerExceptionResolvers(List<HandlerExceptionResolver> exceptionResolvers) {
 	}
 
-	/**
-	 * {@inheritDoc}
-	 * <p>This implementation is empty.
-	 */
-	public MessageCodesResolver getMessageCodesResolver() {
-		return null;
-	}
-
 	/**
 	 * {@inheritDoc}
 	 * <p>This implementation is empty.
@@ -135,4 +119,20 @@ public abstract class WebMvcConfigurerAdapter implements WebMvcConfigurer {
 	public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
 	}
 
+	/**
+	 * {@inheritDoc}
+	 * <p>This implementation returns {@code null}.
+	 */
+	public Validator getValidator() {
+		return null;
+	}
+
+	/**
+	 * {@inheritDoc}
+	 * <p>This implementation returns {@code null}.
+	 */
+	public MessageCodesResolver getMessageCodesResolver() {
+		return null;
+	}
+
 }

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

@@ -21,6 +21,7 @@ import java.util.List;
 
 import org.springframework.format.FormatterRegistry;
 import org.springframework.http.converter.HttpMessageConverter;
+import org.springframework.util.CollectionUtils;
 import org.springframework.validation.MessageCodesResolver;
 import org.springframework.validation.Validator;
 import org.springframework.web.method.support.HandlerMethodArgumentResolver;
@@ -28,7 +29,7 @@ import org.springframework.web.method.support.HandlerMethodReturnValueHandler;
 import org.springframework.web.servlet.HandlerExceptionResolver;
 
 /**
- * An {@link WebMvcConfigurer} implementation that delegates to other {@link WebMvcConfigurer} instances.
+ * A {@link WebMvcConfigurer} that delegates to one or more others.
  *
  * @author Rossen Stoyanchev
  * @since 3.1
@@ -37,12 +38,14 @@ class WebMvcConfigurerComposite implements WebMvcConfigurer {
 
 	private final List<WebMvcConfigurer> delegates = new ArrayList<WebMvcConfigurer>();
 
+
 	public void addWebMvcConfigurers(List<WebMvcConfigurer> configurers) {
-		if (configurers != null) {
+		if (!CollectionUtils.isEmpty(configurers)) {
 			this.delegates.addAll(configurers);
 		}
 	}
 
+
 	public void addFormatters(FormatterRegistry registry) {
 		for (WebMvcConfigurer delegate : this.delegates) {
 			delegate.addFormatters(registry);
@@ -126,6 +129,17 @@ class WebMvcConfigurerComposite implements WebMvcConfigurer {
 		return selectSingleInstance(candidates, Validator.class);
 	}
 
+	public MessageCodesResolver getMessageCodesResolver() {
+		List<MessageCodesResolver> candidates = new ArrayList<MessageCodesResolver>();
+		for (WebMvcConfigurer configurer : this.delegates) {
+			MessageCodesResolver messageCodesResolver = configurer.getMessageCodesResolver();
+			if (messageCodesResolver != null) {
+				candidates.add(messageCodesResolver);
+			}
+		}
+		return selectSingleInstance(candidates, MessageCodesResolver.class);
+	}
+
 	private <T> T selectSingleInstance(List<T> instances, Class<T> instanceType) {
 		if (instances.size() > 1) {
 			throw new IllegalStateException(
@@ -139,15 +153,4 @@ class WebMvcConfigurerComposite implements WebMvcConfigurer {
 		}
 	}
 
-	public MessageCodesResolver getMessageCodesResolver() {
-		List<MessageCodesResolver> candidates = new ArrayList<MessageCodesResolver>();
-		for (WebMvcConfigurer configurer : this.delegates) {
-			MessageCodesResolver messageCodesResolver = configurer.getMessageCodesResolver();
-			if (messageCodesResolver != null) {
-				candidates.add(messageCodesResolver);
-			}
-		}
-		return selectSingleInstance(candidates, MessageCodesResolver.class);
-	}
-
 }

spring-webmvc/src/test/java/org/springframework/web/servlet/config/annotation/DelegatingWebMvcConfigurationTests.java

@@ -17,7 +17,7 @@
 package org.springframework.web.servlet.config.annotation;
 
 import java.util.ArrayList;
-import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 
 import org.junit.Before;
@@ -26,6 +26,7 @@ import org.mockito.ArgumentCaptor;
 import org.mockito.Captor;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
+
 import org.springframework.core.convert.ConversionService;
 import org.springframework.format.support.FormattingConversionService;
 import org.springframework.http.converter.HttpMessageConverter;
@@ -88,10 +89,10 @@ public class DelegatingWebMvcConfigurationTests {
 		delegatingConfig = new DelegatingWebMvcConfiguration();
 	}
 
+
 	@Test
 	public void requestMappingHandlerAdapter() throws Exception {
-
-		delegatingConfig.setConfigurers(Arrays.asList(webMvcConfigurer));
+		delegatingConfig.setConfigurers(Collections.singletonList(webMvcConfigurer));
 		RequestMappingHandlerAdapter adapter = delegatingConfig.requestMappingHandlerAdapter();
 
 		ConfigurableWebBindingInitializer initializer = (ConfigurableWebBindingInitializer) adapter.getWebBindingInitializer();
@@ -132,7 +133,7 @@ public class DelegatingWebMvcConfigurationTests {
 	public void getCustomValidator() {
 		given(webMvcConfigurer.getValidator()).willReturn(new LocalValidatorFactoryBean());
 
-		delegatingConfig.setConfigurers(Arrays.asList(webMvcConfigurer));
+		delegatingConfig.setConfigurers(Collections.singletonList(webMvcConfigurer));
 		delegatingConfig.mvcValidator();
 
 		verify(webMvcConfigurer).getValidator();
@@ -142,7 +143,7 @@ public class DelegatingWebMvcConfigurationTests {
 	public void getCustomMessageCodesResolver() {
 		given(webMvcConfigurer.getMessageCodesResolver()).willReturn(new DefaultMessageCodesResolver());
 
-		delegatingConfig.setConfigurers(Arrays.asList(webMvcConfigurer));
+		delegatingConfig.setConfigurers(Collections.singletonList(webMvcConfigurer));
 		delegatingConfig.getMessageCodesResolver();
 
 		verify(webMvcConfigurer).getMessageCodesResolver();
@@ -150,8 +151,7 @@ public class DelegatingWebMvcConfigurationTests {
 
 	@Test
 	public void handlerExceptionResolver() throws Exception {
-
-		delegatingConfig.setConfigurers(Arrays.asList(webMvcConfigurer));
+		delegatingConfig.setConfigurers(Collections.singletonList(webMvcConfigurer));
 		delegatingConfig.handlerExceptionResolver();
 
 		verify(webMvcConfigurer).configureMessageConverters(converters.capture());
@@ -177,7 +177,7 @@ public class DelegatingWebMvcConfigurationTests {
 		delegatingConfig.setConfigurers(configurers);
 
 		HandlerExceptionResolverComposite composite =
-			(HandlerExceptionResolverComposite) delegatingConfig.handlerExceptionResolver();
+				(HandlerExceptionResolverComposite) delegatingConfig.handlerExceptionResolver();
 		assertEquals("Only one custom converter is expected", 1, composite.getExceptionResolvers().size());
 	}
 
@@ -200,11 +200,16 @@ public class DelegatingWebMvcConfigurationTests {
 
 		RequestMappingHandlerMapping handlerMapping = delegatingConfig.requestMappingHandlerMapping();
 		assertNotNull(handlerMapping);
-		assertTrue(handlerMapping.useRegisteredSuffixPatternMatch());
-		assertTrue(handlerMapping.useSuffixPatternMatch());
-		assertFalse(handlerMapping.useTrailingSlashMatch());
-		assertSame(pathHelper, handlerMapping.getUrlPathHelper());
-		assertSame(pathMatcher, handlerMapping.getPathMatcher());
+		assertEquals("PathMatchConfigurer should configure RegisteredSuffixPatternMatch",
+				true, handlerMapping.useRegisteredSuffixPatternMatch());
+		assertEquals("PathMatchConfigurer should configure SuffixPatternMatch",
+				true, handlerMapping.useSuffixPatternMatch());
+		assertEquals("PathMatchConfigurer should configure TrailingSlashMatch",
+				false, handlerMapping.useTrailingSlashMatch());
+		assertEquals("PathMatchConfigurer should configure UrlPathHelper",
+				pathHelper, handlerMapping.getUrlPathHelper());
+		assertEquals("PathMatchConfigurer should configure PathMatcher",
+				pathMatcher, handlerMapping.getPathMatcher());
 	}
 
 }