Add MessageCodesResolver hook to WebMvcConfigurer

This change makes it possible to provide a custom MessageCodesResolver
through the MVC Java config whether using @EnableWebMvc and extending
WebMVcConfigurerAdapter or sub-classing directly from
WebMvcConfigurationSupport.

Issue: SPR-9223

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2011 the original author or authors.
+ * Copyright 2002-2012 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.
@@ -35,6 +35,7 @@ import org.junit.Test;
 import org.springframework.format.support.FormattingConversionService;
 import org.springframework.http.converter.HttpMessageConverter;
 import org.springframework.http.converter.StringHttpMessageConverter;
+import org.springframework.validation.DefaultMessageCodesResolver;
 import org.springframework.validation.beanvalidation.LocalValidatorFactoryBean;
 import org.springframework.web.bind.support.ConfigurableWebBindingInitializer;
 import org.springframework.web.method.support.HandlerMethodArgumentResolver;
@@ -72,6 +73,7 @@ public class DelegatingWebMvcConfigurationTests {
 
 		configurer.configureMessageConverters(capture(converters));
 		expect(configurer.getValidator()).andReturn(null);
+		expect(configurer.getMessageCodesResolver()).andReturn(null);
 		configurer.addFormatters(capture(conversionService));
 		configurer.addArgumentResolvers(capture(resolvers));
 		configurer.addReturnValueHandlers(capture(handlers));
@@ -91,7 +93,7 @@ public class DelegatingWebMvcConfigurationTests {
 		verify(configurer);
 	}
 
-	@Test 
+	@Test
 	public void configureMessageConverters() {
 		List<WebMvcConfigurer> configurers = new ArrayList<WebMvcConfigurer>();
 		configurers.add(new WebMvcConfigurerAdapter() {
@@ -102,11 +104,11 @@ public class DelegatingWebMvcConfigurationTests {
 		});
 		mvcConfiguration = new DelegatingWebMvcConfiguration();
 		mvcConfiguration.setConfigurers(configurers);
-		
+
 		RequestMappingHandlerAdapter adapter = mvcConfiguration.requestMappingHandlerAdapter();
 		assertEquals("Only one custom converter should be registered", 1, adapter.getMessageConverters().size());
 	}
-	
+
 	@Test
 	public void getCustomValidator() {
 		expect(configurer.getValidator()).andReturn(new LocalValidatorFactoryBean());
@@ -118,6 +120,17 @@ public class DelegatingWebMvcConfigurationTests {
 		verify(configurer);
 	}
 
+	@Test
+	public void getCustomMessageCodesResolver() {
+		expect(configurer.getMessageCodesResolver()).andReturn(new DefaultMessageCodesResolver());
+		replay(configurer);
+
+		mvcConfiguration.setConfigurers(Arrays.asList(configurer));
+		mvcConfiguration.getMessageCodesResolver();
+
+		verify(configurer);
+	}
+
 	@Test
 	public void handlerExceptionResolver() throws Exception {
 		Capture<List<HttpMessageConverter<?>>> converters = new Capture<List<HttpMessageConverter<?>>>();
@@ -139,7 +152,7 @@ public class DelegatingWebMvcConfigurationTests {
 		verify(configurer);
 	}
 
-	@Test 
+	@Test
 	public void configureExceptionResolvers() throws Exception {
 		List<WebMvcConfigurer> configurers = new ArrayList<WebMvcConfigurer>();
 		configurers.add(new WebMvcConfigurerAdapter() {
@@ -149,10 +162,10 @@ public class DelegatingWebMvcConfigurationTests {
 			}
 		});
 		mvcConfiguration.setConfigurers(configurers);
-		
-		HandlerExceptionResolverComposite composite = 
+
+		HandlerExceptionResolverComposite composite =
 			(HandlerExceptionResolverComposite) mvcConfiguration.handlerExceptionResolver();
 		assertEquals("Only one custom converter is expected", 1, composite.getExceptionResolvers().size());
 	}
-	
+
 }

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

@@ -40,7 +40,9 @@ import org.springframework.mock.web.MockHttpServletRequest;
 import org.springframework.mock.web.MockServletContext;
 import org.springframework.stereotype.Controller;
 import org.springframework.validation.BeanPropertyBindingResult;
+import org.springframework.validation.DefaultMessageCodesResolver;
 import org.springframework.validation.Errors;
+import org.springframework.validation.MessageCodesResolver;
 import org.springframework.validation.Validator;
 import org.springframework.validation.beanvalidation.LocalValidatorFactoryBean;
 import org.springframework.web.bind.annotation.RequestMapping;
@@ -190,6 +192,9 @@ public class WebMvcConfigurationSupportTests {
 		initializer.getValidator().validate(null, bindingResult);
 		assertEquals("invalid", bindingResult.getAllErrors().get(0).getCode());
 
+		String[] codes = initializer.getMessageCodesResolver().resolveMessageCodes("invalid", null);
+		assertEquals("custom.invalid", codes[0]);
+
 		@SuppressWarnings("unchecked")
 		List<HandlerMethodArgumentResolver> argResolvers= (List<HandlerMethodArgumentResolver>)
 			new DirectFieldAccessor(adapter).getPropertyValue("customArgumentResolvers");
@@ -248,8 +253,11 @@ public class WebMvcConfigurationSupportTests {
 	}
 
 	/**
-	 * The purpose of this class is to test that an implementation of a {@link WebMvcConfigurer}
-	 * can also apply customizations by extension from {@link WebMvcConfigurationSupport}.
+	 * Since WebMvcConfigurationSupport does not implement WebMvcConfigurer, the purpose
+	 * of this test class is also to ensure the two are in sync with each other. Effectively
+	 * that ensures that application config classes that use the combo {@code @EnableWebMvc}
+	 * plus WebMvcConfigurer can switch to extending WebMvcConfigurationSupport directly for
+	 * more advanced configuration needs.
 	 */
 	private class WebConfig extends WebMvcConfigurationSupport implements WebMvcConfigurer {
 
@@ -299,6 +307,17 @@ public class WebMvcConfigurationSupportTests {
 			registry.addInterceptor(new LocaleChangeInterceptor());
 		}
 
+		@SuppressWarnings("serial")
+		@Override
+		public MessageCodesResolver getMessageCodesResolver() {
+			return new DefaultMessageCodesResolver() {
+				@Override
+				public String[] resolveMessageCodes(String errorCode, String objectName) {
+					return new String[] { "custom." + errorCode };
+				}
+			};
+		}
+
 		@Override
 		public void addViewControllers(ViewControllerRegistry registry) {
 			registry.addViewController("/path");
@@ -313,6 +332,7 @@ public class WebMvcConfigurationSupportTests {
 		public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
 			configurer.enable("default");
 		}
+
 	}
 
 }