SPR-6464 Polish following code review.

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/FlashMap.java

@@ -17,10 +17,10 @@
 package org.springframework.web.servlet;
 
 import java.util.HashMap;
-import java.util.LinkedHashMap;
-import java.util.Map;
 
-import org.springframework.beans.BeanUtils;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.util.StringUtils;
 
 /**
  * A FlashMap provides a way for one request to store attributes intended for 
@@ -35,7 +35,7 @@ import org.springframework.beans.BeanUtils;
  * recipient. On a redirect, the target URL is known and for example
  * {@code org.springframework.web.servlet.view.RedirectView} has the
  * opportunity to automatically update the current FlashMap with target
- * URL information .
+ * URL information.
  * 
  * <p>Annotated controllers will usually not use this type directly.
  * See {@code org.springframework.web.servlet.mvc.support.RedirectAttributes}
@@ -46,13 +46,13 @@ import org.springframework.beans.BeanUtils;
  * 
  * @see FlashMapManager
  */
-public class FlashMap extends HashMap<String, Object> implements Comparable<FlashMap> {
+public final class FlashMap extends HashMap<String, Object> implements Comparable<FlashMap> {
 
 	private static final long serialVersionUID = 1L;
 	
 	private String targetRequestPath;
 	
-	private final Map<String, String> targetRequestParams = new LinkedHashMap<String, String>();
+	private final MultiValueMap<String, String> targetRequestParams = new LinkedMultiValueMap<String, String>();
 	
 	private long expirationStartTime;
 	
@@ -93,17 +93,15 @@ public class FlashMap extends HashMap<String, Object> implements Comparable<Flas
 	}
 
 	/**
-	 * Provide request parameter pairs to identify the request for this FlashMap. 
-	 * Only simple type, non-null parameter values are used.
+	 * Provide request parameters identifying the request for this FlashMap.
+	 * Null or empty keys and values are skipped.
 	 * @param params a Map with the names and values of expected parameters.
-	 * @see BeanUtils#isSimpleValueType(Class)
 	 */
-	public FlashMap addTargetRequestParams(Map<String, ?> params) {
+	public FlashMap addTargetRequestParams(MultiValueMap<String, String> params) {
 		if (params != null) {
-			for (String name : params.keySet()) {
-				Object value = params.get(name);
-				if ((value != null) && BeanUtils.isSimpleValueType(value.getClass())) {
-					this.targetRequestParams.put(name, value.toString());
+			for (String key : params.keySet()) {
+				for (String value : params.get(key)) {
+					addTargetRequestParam(key, value);
 				}
 			}
 		}
@@ -111,19 +109,21 @@ public class FlashMap extends HashMap<String, Object> implements Comparable<Flas
 	}
 
 	/**
-	 * Provide a request parameter to identify the request for this FlashMap.
-	 * @param name the name of the expected parameter, never {@code null}
-	 * @param value the value for the expected parameter, never {@code null}
+	 * Provide a request parameter identifying the request for this FlashMap.
+	 * @param name the expected parameter name, skipped if {@code null}
+	 * @param value the expected parameter value, skipped if {@code null}
 	 */
 	public FlashMap addTargetRequestParam(String name, String value) {
-		this.targetRequestParams.put(name, value.toString());
+		if (StringUtils.hasText(name) && StringUtils.hasText(value)) {
+			this.targetRequestParams.add(name, value);
+		}
 		return this;
 	}
 	
 	/**
-	 * Return the parameters identifying the target request, or an empty Map.
+	 * Return the parameters identifying the target request, or an empty map.
 	 */
-	public Map<String, String> getTargetRequestParams() {
+	public MultiValueMap<String, String> getTargetRequestParams() {
 		return targetRequestParams;
 	}
 
@@ -174,11 +174,11 @@ public class FlashMap extends HashMap<String, Object> implements Comparable<Flas
 
 	@Override
 	public String toString() {
-		StringBuilder result = new StringBuilder();
-		result.append("[Attributes=").append(super.toString());
-		result.append(", targetRequestPath=").append(this.targetRequestPath);
-		result.append(", targetRequestParams=" + this.targetRequestParams.toString()).append("]");
-		return result.toString();
+		StringBuilder sb = new StringBuilder();
+		sb.append("[Attributes=").append(super.toString());
+		sb.append(", targetRequestPath=").append(this.targetRequestPath);
+		sb.append(", targetRequestParams=").append(this.targetRequestParams).append("]");
+		return sb.toString();
 	}
 
 }

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/FlashMapManager.java

@@ -29,8 +29,7 @@ import javax.servlet.http.HttpServletRequest;
  * instances are exposed as request attributes and are accessible via methods
  * in {@code org.springframework.web.servlet.support.RequestContextUtils}.
  * 
- * <p>Annotated controllers are most likely to store and access flash attributes
- * through their model. 
+ * <p>Annotated controllers will usually not use this FlashMap directly.
  * See {@code org.springframework.web.servlet.mvc.support.RedirectAttributes}.
  * 
  * @author Rossen Stoyanchev

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/config/AnnotationDrivenBeanDefinitionParser.java

@@ -130,6 +130,7 @@ class AnnotationDrivenBeanDefinitionParser implements BeanDefinitionParser {
 		methodAdapterDef.setRole(BeanDefinition.ROLE_INFRASTRUCTURE);
 		methodAdapterDef.getPropertyValues().add("webBindingInitializer", bindingDef);
 		methodAdapterDef.getPropertyValues().add("messageConverters", messageConverters);
+		methodAdapterDef.getPropertyValues().add("ignoreDefaultModelOnRedirect", true);
 		if (argumentResolvers != null) {
 			methodAdapterDef.getPropertyValues().add("customArgumentResolvers", argumentResolvers);
 		}

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

@@ -73,42 +73,59 @@ import org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandl
 import org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver;
 
 /**
- * A base class that provides default configuration for Spring MVC applications by registering Spring MVC 
- * infrastructure components to be detected by the {@link DispatcherServlet}. Typically applications should not
- * have to extend this class. A more likely place to start is to annotate an @{@link Configuration}
- * class with @{@link EnableWebMvc} (see @{@link EnableWebMvc} and {@link WebMvcConfigurer} for details).
+ * A base class that provides default configuration for Spring MVC applications 
+ * by registering Spring MVC infrastructure components to be detected by the 
+ * {@link DispatcherServlet}. An application configuration class is not required
+ * to extend this class. A more likely place to start is to annotate 
+ * an @{@link Configuration} class with @{@link EnableWebMvc} 
+ * (see @{@link EnableWebMvc} and {@link WebMvcConfigurer} for details).
  * 
- * <p>If using @{@link EnableWebMvc} does not give you all you need, consider extending directly from this 
- * class. Remember to add @{@link Configuration} to your subclass and @{@link Bean} to any superclass 
- * @{@link Bean} methods you choose to override.
+ * <p>If the customization options available with use of @{@link EnableWebMvc} 
+ * are not enough, consider extending directly from this class and override the
+ * appropriate methods. Remember to add @{@link Configuration} to your subclass 
+ * and @{@link Bean} to any superclass @{@link Bean} methods you override.
  * 
  * <p>This class registers the following {@link HandlerMapping}s:</p>
  * <ul>
- * 	<li>{@link RequestMappingHandlerMapping} ordered at 0 for mapping requests to annotated controller methods.
- * 	<li>{@link HandlerMapping} ordered at 1 to map URL paths directly to view names.
- * 	<li>{@link BeanNameUrlHandlerMapping} ordered at 2 to map URL paths to controller bean names.
- * 	<li>{@link HandlerMapping} ordered at {@code Integer.MAX_VALUE-1} to serve static resource requests.
- * 	<li>{@link HandlerMapping} ordered at {@code Integer.MAX_VALUE} to forward requests to the default servlet.
+ * 	<li>{@link RequestMappingHandlerMapping} 
+ * 	ordered at 0 for mapping requests to annotated controller methods.
+ * 	<li>{@link HandlerMapping} 
+ * 	ordered at 1 to map URL paths directly to view names.
+ * 	<li>{@link BeanNameUrlHandlerMapping} 
+ * 	ordered at 2 to map URL paths to controller bean names.
+ * 	<li>{@link HandlerMapping} 
+ * 	ordered at {@code Integer.MAX_VALUE-1} to serve static resource requests.
+ * 	<li>{@link HandlerMapping} 
+ * 	ordered at {@code Integer.MAX_VALUE} to forward requests to the default servlet.
  * </ul>
  *
  * <p>Registers these {@link HandlerAdapter}s:
  * <ul>
- * 	<li>{@link RequestMappingHandlerAdapter} for processing requests with annotated controller methods.
- * 	<li>{@link HttpRequestHandlerAdapter} for processing requests with {@link HttpRequestHandler}s.
- * 	<li>{@link SimpleControllerHandlerAdapter} for processing requests with interface-based {@link Controller}s.
+ * 	<li>{@link RequestMappingHandlerAdapter} 
+ * 	for processing requests with annotated controller methods.
+ * 	<li>{@link HttpRequestHandlerAdapter} 
+ * 	for processing requests with {@link HttpRequestHandler}s.
+ * 	<li>{@link SimpleControllerHandlerAdapter} 
+ * 	for processing requests with interface-based {@link Controller}s.
  * </ul>
  *
- * <p>Registers a {@link HandlerExceptionResolverComposite} with this chain of exception resolvers:
+ * <p>Registers a {@link HandlerExceptionResolverComposite} with this chain of
+ * exception resolvers:
  * <ul>
- * 	<li>{@link ExceptionHandlerExceptionResolver} for handling exceptions through @{@link ExceptionHandler} methods.
- * 	<li>{@link ResponseStatusExceptionResolver} for exceptions annotated with @{@link ResponseStatus}.
- * 	<li>{@link DefaultHandlerExceptionResolver} for resolving known Spring exception types
+ * 	<li>{@link ExceptionHandlerExceptionResolver} for handling exceptions 
+ * 	through @{@link ExceptionHandler} methods.
+ * 	<li>{@link ResponseStatusExceptionResolver} for exceptions annotated 
+ * 	with @{@link ResponseStatus}.
+ * 	<li>{@link DefaultHandlerExceptionResolver} for resolving known Spring 
+ * 	exception types
  * </ul>
  *
  * <p>Registers these other instances:
  * <ul>
- * 	<li>{@link FormattingConversionService} for use with annotated controller methods and the spring:eval JSP tag.
- * 	<li>{@link Validator} for validating model attributes on annotated controller methods.
+ * 	<li>{@link FormattingConversionService} 
+ * 	for use with annotated controller methods and the spring:eval JSP tag.
+ * 	<li>{@link Validator} 
+ * 	for validating model attributes on annotated controller methods.
  * </ul>
  *
  * @see EnableWebMvc
@@ -137,7 +154,8 @@ public abstract class WebMvcConfigurationSupport implements ApplicationContextAw
 	}
 	
 	/**
-	 * Returns a {@link RequestMappingHandlerMapping} ordered at 0 for mapping requests to annotated controllers.
+	 * Return a {@link RequestMappingHandlerMapping} ordered at 0 for mapping 
+	 * requests to annotated controllers.
 	 */
 	@Bean
 	public RequestMappingHandlerMapping requestMappingHandlerMapping() {
@@ -148,8 +166,9 @@ public abstract class WebMvcConfigurationSupport implements ApplicationContextAw
 	}
 	
 	/**
-	 * Provides access to the shared handler interceptors used to configure {@link HandlerMapping} instances with.
-	 * This method cannot be overridden, use {@link #addInterceptors(InterceptorRegistry)} instead. 
+	 * Provide access to the shared handler interceptors used to configure 
+	 * {@link HandlerMapping} instances with. This method cannot be overridden, 
+	 * use {@link #addInterceptors(InterceptorRegistry)} instead. 
 	 */
 	protected final Object[] getInterceptors() {
 		if (interceptors == null) {
@@ -162,15 +181,17 @@ public abstract class WebMvcConfigurationSupport implements ApplicationContextAw
 	}
 	
 	/**
-	 * Override this method to add Spring MVC interceptors for pre/post-processing of controller invocation.
+	 * Override this method to add Spring MVC interceptors for 
+	 * pre- and post-processing of controller invocation.
 	 * @see InterceptorRegistry
 	 */
 	protected void addInterceptors(InterceptorRegistry registry) {
 	}
 
 	/**
-	 * Returns a handler mapping ordered at 1 to map URL paths directly to view names.
-	 * To configure view controllers, override {@link #addViewControllers(ViewControllerRegistry)}. 
+	 * Return a handler mapping ordered at 1 to map URL paths directly to 
+	 * view names. To configure view controllers, override 
+	 * {@link #addViewControllers}. 
 	 */
 	@Bean
 	public HandlerMapping viewControllerHandlerMapping() {
@@ -191,7 +212,8 @@ public abstract class WebMvcConfigurationSupport implements ApplicationContextAw
 	}
 	
 	/**
-	 * Returns a {@link BeanNameUrlHandlerMapping} ordered at 2 to map URL paths to controller bean names.
+	 * Return a {@link BeanNameUrlHandlerMapping} ordered at 2 to map URL 
+	 * paths to controller bean names.
 	 */
 	@Bean
 	public BeanNameUrlHandlerMapping beanNameHandlerMapping() {
@@ -202,8 +224,9 @@ public abstract class WebMvcConfigurationSupport implements ApplicationContextAw
 	}
 
 	/**
-	 * Returns a handler mapping ordered at Integer.MAX_VALUE-1 with mapped resource handlers.
-	 * To configure resource handling, override {@link #addResourceHandlers(ResourceHandlerRegistry)}.
+	 * Return a handler mapping ordered at Integer.MAX_VALUE-1 with mapped 
+	 * resource handlers. To configure resource handling, override 
+	 * {@link #addResourceHandlers}.
 	 */
 	@Bean
 	public HandlerMapping resourceHandlerMapping() {
@@ -222,9 +245,9 @@ public abstract class WebMvcConfigurationSupport implements ApplicationContextAw
 	}
 
 	/**
-	 * Returns a handler mapping ordered at Integer.MAX_VALUE with a mapped default servlet handler.
-	 * To configure "default" Servlet handling, override 
-	 * {@link #configureDefaultServletHandling(DefaultServletHandlerConfigurer)}.  
+	 * Return a handler mapping ordered at Integer.MAX_VALUE with a mapped 
+	 * default servlet handler. To configure "default" Servlet handling, 
+	 * override {@link #configureDefaultServletHandling}.  
 	 */
 	@Bean
 	public HandlerMapping defaultServletHandlerMapping() {
@@ -243,12 +266,13 @@ public abstract class WebMvcConfigurationSupport implements ApplicationContextAw
 	}
 
 	/**
-	 * Returns a {@link RequestMappingHandlerAdapter} for processing requests through annotated controller methods.
-	 * Consider overriding one of these other more fine-grained methods:
+	 * Returns a {@link RequestMappingHandlerAdapter} for processing requests 
+	 * through annotated controller methods. Consider overriding one of these 
+	 * other more fine-grained methods:
 	 * <ul>
-	 *  <li>{@link #addArgumentResolvers(List)} for adding custom argument resolvers.
-	 * 	<li>{@link #addReturnValueHandlers(List)} for adding custom return value handlers.
-	 * 	<li>{@link #configureMessageConverters(List)} for adding custom message converters.
+	 *  <li>{@link #addArgumentResolvers} for adding custom argument resolvers.
+	 * 	<li>{@link #addReturnValueHandlers} for adding custom return value handlers.
+	 * 	<li>{@link #configureMessageConverters} for adding custom message converters.
 	 * </ul>
 	 */
 	@Bean
@@ -268,34 +292,46 @@ public abstract class WebMvcConfigurationSupport implements ApplicationContextAw
 		adapter.setWebBindingInitializer(webBindingInitializer);
 		adapter.setCustomArgumentResolvers(argumentResolvers);
 		adapter.setCustomReturnValueHandlers(returnValueHandlers);
+		adapter.setIgnoreDefaultModelOnRedirect(true);
 		return adapter;
 	}
 
 	/**
-	 * Add custom {@link HandlerMethodArgumentResolver}s to use in addition to the ones registered by default.
-	 * <p>Custom argument resolvers are invoked before built-in resolvers except for those that rely on the presence 
-	 * of annotations (e.g. {@code @RequestParameter}, {@code @PathVariable}, etc.). The latter can be customized 
-	 * by configuring the {@link RequestMappingHandlerAdapter} directly. 
-	 * @param argumentResolvers the list of custom converters; initially an empty list.
+	 * Add custom {@link HandlerMethodArgumentResolver}s to use in addition to 
+	 * the ones registered by default.
+	 * <p>Custom argument resolvers are invoked before built-in resolvers 
+	 * except for those that rely on the presence of annotations (e.g. 
+	 * {@code @RequestParameter}, {@code @PathVariable}, etc.). 
+	 * The latter can  be customized by configuring the 
+	 * {@link RequestMappingHandlerAdapter} directly. 
+	 * @param argumentResolvers the list of custom converters; 
+	 * 	initially an empty list.
 	 */
 	protected void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
 	}
 
 	/**
-	 * Add custom {@link HandlerMethodReturnValueHandler}s in addition to the ones registered by default.
-	 * <p>Custom return value handlers are invoked before built-in ones except for those that rely on the presence 
-	 * of annotations (e.g. {@code @ResponseBody}, {@code @ModelAttribute}, etc.). The latter can be customized
-	 * by configuring the {@link RequestMappingHandlerAdapter} directly.
-	 * @param returnValueHandlers the list of custom handlers; initially an empty list.
+	 * Add custom {@link HandlerMethodReturnValueHandler}s in addition to the 
+	 * ones registered by default.
+	 * <p>Custom return value handlers are invoked before built-in ones except 
+	 * for those that rely on the presence of annotations (e.g. 
+	 * {@code @ResponseBody}, {@code @ModelAttribute}, etc.). 
+	 * The latter can be customized by configuring the 
+	 * {@link RequestMappingHandlerAdapter} directly.
+	 * @param returnValueHandlers the list of custom handlers; 
+	 * initially an empty list.
 	 */
 	protected void addReturnValueHandlers(List<HandlerMethodReturnValueHandler> returnValueHandlers) {
 	}
 
 	/**
 	 * Provides access to the shared {@link HttpMessageConverter}s used by the 
-	 * {@link RequestMappingHandlerAdapter} and the {@link ExceptionHandlerExceptionResolver}. 
-	 * This method cannot be overridden. Use {@link #configureMessageConverters(List)} instead.
-	 * Also see {@link #addDefaultHttpMessageConverters(List)} that can be used to add default message converters.
+	 * {@link RequestMappingHandlerAdapter} and the 
+	 * {@link ExceptionHandlerExceptionResolver}. 
+	 * This method cannot be overridden. 
+	 * Use {@link #configureMessageConverters(List)} instead.
+	 * Also see {@link #addDefaultHttpMessageConverters(List)} that can be 
+	 * used to add default message converters.
 	 */
 	protected final List<HttpMessageConverter<?>> getMessageConverters() {
 		if (messageConverters == null) {
@@ -309,17 +345,20 @@ public abstract class WebMvcConfigurationSupport implements ApplicationContextAw
 	}
 
 	/**
-	 * Override this method to add custom {@link HttpMessageConverter}s to use with 
-	 * the {@link RequestMappingHandlerAdapter} and the {@link ExceptionHandlerExceptionResolver}.
-	 * Adding converters to the list turns off the default converters that would otherwise be registered by default.
-	 * Also see {@link #addDefaultHttpMessageConverters(List)} that can be used to add default message converters.
-	 * @param converters a list to add message converters to; initially an empty list.
+	 * Override this method to add custom {@link HttpMessageConverter}s to use 
+	 * with the {@link RequestMappingHandlerAdapter} and the 
+	 * {@link ExceptionHandlerExceptionResolver}. Adding converters to the 
+	 * list turns off the default converters that would otherwise be registered
+	 * by default. Also see {@link #addDefaultHttpMessageConverters(List)} that 
+	 * can be used to add default message converters.
+	 * @param converters a list to add message converters to; 
+	 * initially an empty list.
 	 */
 	protected void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
 	}
 
 	/**
-	 * A method available to subclasses to add default {@link HttpMessageConverter}s. 
+	 * Override this method to add default {@link HttpMessageConverter}s. 
 	 * @param messageConverters the list to add the default message converters to
 	 */
 	protected final void addDefaultHttpMessageConverters(List<HttpMessageConverter<?>> messageConverters) {
@@ -346,9 +385,9 @@ public abstract class WebMvcConfigurationSupport implements ApplicationContextAw
 	}
 	
 	/**
-	 * Returns a {@link FormattingConversionService} for use with annotated controller methods and the 
-	 * {@code spring:eval} JSP tag. Also see {@link #addFormatters(FormatterRegistry)} as an alternative
-	 * to overriding this method.
+	 * Returns a {@link FormattingConversionService} for use with annotated 
+	 * controller methods and the {@code spring:eval} JSP tag. 
+	 * Also see {@link #addFormatters} as an alternative to overriding this method.
 	 */
 	@Bean
 	public FormattingConversionService mvcConversionService() {
@@ -364,8 +403,9 @@ public abstract class WebMvcConfigurationSupport implements ApplicationContextAw
 	}
 
 	/**
-	 * Returns {@link Validator} for validating {@code @ModelAttribute} and {@code @RequestBody} arguments of 
-	 * annotated controller methods. To configure a custom validation, override {@link #getValidator()}.
+	 * Returns {@link Validator} for validating {@code @ModelAttribute} 
+	 * and {@code @RequestBody} arguments of annotated controller methods. 
+	 * To configure a custom validation, override {@link #getValidator()}.
 	 */
 	@Bean
 	Validator mvcValidator() {
@@ -404,7 +444,8 @@ public abstract class WebMvcConfigurationSupport implements ApplicationContextAw
 	}
 
 	/**
-	 * Returns a {@link HttpRequestHandlerAdapter} for processing requests with {@link HttpRequestHandler}s.
+	 * Returns a {@link HttpRequestHandlerAdapter} for processing requests 
+	 * with {@link HttpRequestHandler}s.
 	 */
 	@Bean
 	public HttpRequestHandlerAdapter httpRequestHandlerAdapter() {
@@ -412,7 +453,8 @@ public abstract class WebMvcConfigurationSupport implements ApplicationContextAw
 	}
 
 	/**
-	 * Returns a {@link SimpleControllerHandlerAdapter} for processing requests with interface-based controllers.
+	 * Returns a {@link SimpleControllerHandlerAdapter} for processing requests 
+	 * with interface-based controllers.
 	 */
 	@Bean
 	public SimpleControllerHandlerAdapter simpleControllerHandlerAdapter() {
@@ -420,8 +462,9 @@ public abstract class WebMvcConfigurationSupport implements ApplicationContextAw
 	}
 
 	/**
-	 * Returns a {@link HandlerExceptionResolverComposite} that contains a list of exception resolvers.
-	 * To customize the list of exception resolvers, override {@link #configureHandlerExceptionResolvers(List)}.
+	 * Returns a {@link HandlerExceptionResolverComposite} that contains a list
+	 * of exception resolvers. To customize the list of exception resolvers, 
+	 * override {@link #configureHandlerExceptionResolvers(List)}.
 	 */
 	@Bean
 	HandlerExceptionResolver handlerExceptionResolver() throws Exception {
@@ -439,21 +482,28 @@ public abstract class WebMvcConfigurationSupport implements ApplicationContextAw
 	}
 
 	/**
-	 * Override this method to configure the list of {@link HandlerExceptionResolver}s to use.
-	 * Adding resolvers to the list turns off the default resolvers that would otherwise be registered by default.
-	 * Also see {@link #addDefaultHandlerExceptionResolvers(List)} that can be used to add the default exception resolvers.
-	 * @param exceptionResolvers a list to add exception resolvers to; initially an empty list.
+	 * Override this method to configure the list of 
+	 * {@link HandlerExceptionResolver}s to use. Adding resolvers to the list 
+	 * turns off the default resolvers that would otherwise be registered by 
+	 * default. Also see {@link #addDefaultHandlerExceptionResolvers(List)} 
+	 * that can be used to add the default exception resolvers.
+	 * @param exceptionResolvers a list to add exception resolvers to; 
+	 * initially an empty list.
 	 */
 	protected void configureHandlerExceptionResolvers(List<HandlerExceptionResolver> exceptionResolvers) {
 	}
 
 	/**
-	 * A method available to subclasses for adding default {@link HandlerExceptionResolver}s.
+	 * A method available to subclasses for adding default 
+	 * {@link HandlerExceptionResolver}s.
 	 * <p>Adds the following exception resolvers:
 	 * <ul>
-	 * 	<li>{@link ExceptionHandlerExceptionResolver} for handling exceptions through @{@link ExceptionHandler} methods.
-	 * 	<li>{@link ResponseStatusExceptionResolver} for exceptions annotated with @{@link ResponseStatus}.
-	 * 	<li>{@link DefaultHandlerExceptionResolver} for resolving known Spring exception types
+	 * 	<li>{@link ExceptionHandlerExceptionResolver} 
+	 * 	for handling exceptions through @{@link ExceptionHandler} methods.
+	 * 	<li>{@link ResponseStatusExceptionResolver} 
+	 * 	for exceptions annotated with @{@link ResponseStatus}.
+	 * 	<li>{@link DefaultHandlerExceptionResolver} 
+	 * 	for resolving known Spring exception types
 	 * </ul>
 	 */
 	protected final void addDefaultHandlerExceptionResolvers(List<HandlerExceptionResolver> exceptionResolvers) {

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/ExceptionHandlerExceptionResolver.java

@@ -235,7 +235,7 @@ public class ExceptionHandlerExceptionResolver extends AbstractHandlerMethodExce
 			return null;
 		}
 		
-		if (!mavContainer.isResolveView()) {
+		if (mavContainer.isRequestHandled()) {
 			return new ModelAndView();
 		}
 		else {

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerAdapter.java

@@ -93,7 +93,6 @@ import org.springframework.web.servlet.mvc.method.annotation.support.ServletRequ
 import org.springframework.web.servlet.mvc.method.annotation.support.ServletResponseMethodArgumentResolver;
 import org.springframework.web.servlet.mvc.method.annotation.support.ViewMethodReturnValueHandler;
 import org.springframework.web.servlet.mvc.support.RedirectAttributes;
-import org.springframework.web.servlet.mvc.support.RedirectAttributesModelMap;
 import org.springframework.web.servlet.support.RequestContextUtils;
 import org.springframework.web.util.WebUtils;
 
@@ -147,7 +146,7 @@ public class RequestMappingHandlerAdapter extends AbstractHandlerMethodAdapter i
 
 	private SessionAttributeStore sessionAttributeStore = new DefaultSessionAttributeStore();
 	
-	private boolean alwaysUseRedirectAttributes;
+	private boolean ignoreDefaultModelOnRedirect = false;
 	
 	private final Map<Class<?>, SessionAttributesHandler> sessionAttributesHandlerCache =
 		new ConcurrentHashMap<Class<?>, SessionAttributesHandler>();
@@ -334,19 +333,20 @@ public class RequestMappingHandlerAdapter extends AbstractHandlerMethodAdapter i
 	}
 	
 	/**
-	 * By default a controller uses {@link Model} to select attributes for 
-	 * rendering and for redirecting. However, a controller can also use 
-	 * {@link RedirectAttributes} to select attributes before a redirect.
-	 * <p>When this flag is set to {@code true}, {@link RedirectAttributes} 
-	 * becomes the only way to select attributes for a redirect. 
-	 * In other words, for a redirect a controller must use 
-	 * {@link RedirectAttributes} or no attributes will be used.
-	 * <p>The default value is {@code false}, meaning the {@link Model} is
-	 * used unless {@link RedirectAttributes} is used.
+	 * A controller can use the "default" {@link Model} in rendering and
+	 * redirect scenarios. Alternatively, it can use {@link RedirectAttributes}
+	 * to provide attributes for a redirect scenario.
+	 * <p>When this flag is set to {@code true}, the "default" model is never 
+	 * used in a redirect even if the controller method doesn't explicitly 
+	 * declare a RedirectAttributes argument.
+	 * <p>When set to {@code false}, the "default" model may be used in a 
+	 * redirect if the controller method doesn't explicitly declare a 
+	 * RedirectAttributes argument.
+	 * <p>The default setting is {@code false}.
 	 * @see RedirectAttributes
 	 */
-	public void setAlwaysUseRedirectAttributes(boolean alwaysUseRedirectAttributes) {
-		this.alwaysUseRedirectAttributes = alwaysUseRedirectAttributes;
+	public void setIgnoreDefaultModelOnRedirect(boolean ignoreDefaultModelOnRedirect) {
+		this.ignoreDefaultModelOnRedirect = ignoreDefaultModelOnRedirect;
 	}
 
 	public void setBeanFactory(BeanFactory beanFactory) {
@@ -538,18 +538,14 @@ public class RequestMappingHandlerAdapter extends AbstractHandlerMethodAdapter i
 		ModelAndViewContainer mavContainer = new ModelAndViewContainer();
 		mavContainer.addAllAttributes(RequestContextUtils.getInputFlashMap(request));
 		modelFactory.initModel(webRequest, mavContainer, requestMappingMethod);
+		mavContainer.setIgnoreDefaultModelOnRedirect(this.ignoreDefaultModelOnRedirect);
 
-		if (this.alwaysUseRedirectAttributes) {
-			DataBinder dataBinder = binderFactory.createBinder(webRequest, null, null);
-			mavContainer.setRedirectModel(new RedirectAttributesModelMap(dataBinder));
-		}
-		
 		SessionStatus sessionStatus = new SimpleSessionStatus();
 		
 		requestMappingMethod.invokeAndHandle(webRequest, mavContainer, sessionStatus);
 		modelFactory.updateModel(webRequest, mavContainer, sessionStatus);
 
-		if (!mavContainer.isResolveView()) {
+		if (mavContainer.isRequestHandled()) {
 			return null;
 		}
 		else {

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/ServletInvocableHandlerMethod.java

@@ -75,7 +75,7 @@ public class ServletInvocableHandlerMethod extends InvocableHandlerMethod {
 	 * <p>Return value handling may be skipped entirely when the method returns {@code null} (also possibly due
 	 * to a {@code void} return type) and one of the following additional conditions is true:
 	 * <ul>
-	 * <li>A {@link HandlerMethodArgumentResolver} has set the {@link ModelAndViewContainer#setResolveView(boolean)}
+	 * <li>A {@link HandlerMethodArgumentResolver} has set the {@link ModelAndViewContainer#setRequestHandled(boolean)}
 	 * flag to {@code false} -- e.g. method arguments providing access to the response.
 	 * <li>The request qualifies as "not modified" as defined in {@link ServletWebRequest#checkNotModified(long)}
 	 * and {@link ServletWebRequest#checkNotModified(String)}. In this case a response with "not modified" response
@@ -98,13 +98,13 @@ public class ServletInvocableHandlerMethod extends InvocableHandlerMethod {
 		setResponseStatus((ServletWebRequest) request);
 
 		if (returnValue == null) {
-			if (isRequestNotModified(request) || hasResponseStatus() || !mavContainer.isResolveView()) {
-				mavContainer.setResolveView(false);
+			if (isRequestNotModified(request) || hasResponseStatus() || mavContainer.isRequestHandled()) {
+				mavContainer.setRequestHandled(true);
 				return;
 			}
 		}
 
-		mavContainer.setResolveView(true);
+		mavContainer.setRequestHandled(false);
 
 		try {
 			returnValueHandlers.handleReturnValue(returnValue, getReturnType(), mavContainer, request);

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/support/HttpEntityMethodProcessor.java

@@ -101,7 +101,7 @@ public class HttpEntityMethodProcessor extends AbstractMessageConverterMethodPro
 								  ModelAndViewContainer mavContainer, 
 								  NativeWebRequest webRequest) throws Exception {
 		
-		mavContainer.setResolveView(false);
+		mavContainer.setRequestHandled(true);
 
 		if (returnValue == null) {
 			return;

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/support/ModelAndViewMethodReturnValueHandler.java

@@ -24,7 +24,7 @@ import org.springframework.web.servlet.ModelAndView;
 
 /**
  * Handles return values of type {@link ModelAndView} transferring their content to the {@link ModelAndViewContainer}. 
- * If the return value is {@code null}, the {@link ModelAndViewContainer#setResolveView(boolean)} flag is set to 
+ * If the return value is {@code null}, the {@link ModelAndViewContainer#setRequestHandled(boolean)} flag is set to 
  * {@code false} to indicate view resolution is not needed.
  *
  * @author Rossen Stoyanchev
@@ -49,7 +49,7 @@ public class ModelAndViewMethodReturnValueHandler implements HandlerMethodReturn
 			mavContainer.addAllAttributes(mav.getModel());
 		}
 		else {
-			mavContainer.setResolveView(false);
+			mavContainer.setRequestHandled(true);
 		}
 	}
 

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/support/RedirectAttributesMethodArgumentResolver.java

@@ -49,16 +49,10 @@ public class RedirectAttributesMethodArgumentResolver implements HandlerMethodAr
 								  ModelAndViewContainer mavContainer,
 								  NativeWebRequest webRequest, 
 								  WebDataBinderFactory binderFactory) throws Exception {
-		
-		if (mavContainer.getRedirectModel() != null) {
-			return mavContainer.getRedirectModel();
-		}
-		else {
-			DataBinder dataBinder = binderFactory.createBinder(webRequest, null, null);
-			ModelMap redirectAttributes  = new RedirectAttributesModelMap(dataBinder);
-			mavContainer.setRedirectModel(redirectAttributes);
-			return redirectAttributes;
-		}
+		DataBinder dataBinder = binderFactory.createBinder(webRequest, null, null);
+		ModelMap redirectAttributes  = new RedirectAttributesModelMap(dataBinder);
+		mavContainer.setRedirectModel(redirectAttributes);
+		return redirectAttributes;
 	}
 
 }

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/support/RequestResponseBodyMethodProcessor.java

@@ -98,7 +98,7 @@ public class RequestResponseBodyMethodProcessor extends AbstractMessageConverter
 								  MethodParameter returnType,
 								  ModelAndViewContainer mavContainer,
 								  NativeWebRequest webRequest) throws IOException, HttpMediaTypeNotAcceptableException {
-		mavContainer.setResolveView(false);
+		mavContainer.setRequestHandled(true);
 		if (returnValue != null) {
 			writeWithMessageConverters(returnValue, returnType, webRequest);
 		}

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/support/ServletResponseMethodArgumentResolver.java

@@ -54,7 +54,7 @@ public class ServletResponseMethodArgumentResolver implements HandlerMethodArgum
 
 	/**
 	 * {@inheritDoc}
-	 * <p>Sets the {@link ModelAndViewContainer#setResolveView(boolean)} flag to {@code false} to indicate
+	 * <p>Sets the {@link ModelAndViewContainer#setRequestHandled(boolean)} flag to {@code false} to indicate
 	 * that the method signature provides access to the response. If subsequently the underlying method  
 	 * returns {@code null}, view resolution will be bypassed.
 	 * @see ServletInvocableHandlerMethod#invokeAndHandle(NativeWebRequest, ModelAndViewContainer, Object...)
@@ -64,7 +64,7 @@ public class ServletResponseMethodArgumentResolver implements HandlerMethodArgum
 								  NativeWebRequest webRequest, 
 								  WebDataBinderFactory binderFactory) throws IOException {
 		
-		mavContainer.setResolveView(false);
+		mavContainer.setRequestHandled(true);
 
 		HttpServletResponse response = webRequest.getNativeResponse(HttpServletResponse.class);
 		Class<?> paramType = parameter.getParameterType();

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/mvc/method/annotation/support/ViewMethodReturnValueHandler.java

@@ -61,14 +61,14 @@ public class ViewMethodReturnValueHandler implements HandlerMethodReturnValueHan
 			String viewName = (String) returnValue;
 			mavContainer.setViewName(viewName);
 			if (isRedirectViewName(viewName)) {
-				mavContainer.setUseRedirectModel();
+				mavContainer.setUseRedirectModel(true);
 			}
 		}
 		else if (returnValue instanceof View){
 			View view = (View) returnValue;
 			mavContainer.setView(view);
 			if (isRedirectView(view)) {	
-				mavContainer.setUseRedirectModel();
+				mavContainer.setUseRedirectModel(true);
 			}
 		}
 		else {
@@ -95,7 +95,7 @@ public class ViewMethodReturnValueHandler implements HandlerMethodReturnValueHan
 	 * "false" otherwise.
 	 */
 	protected boolean isRedirectView(View view) {
-		if (SmartView.class.isAssignableFrom(view.getClass())) {
+		if (view instanceof SmartView) {
 			return ((SmartView) view).isRedirectView();
 		}
 		else {

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/support/DefaultFlashMapManager.java

@@ -27,13 +27,14 @@ import javax.servlet.http.HttpSession;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.springframework.util.CollectionUtils;
+import org.springframework.util.MultiValueMap;
 import org.springframework.util.StringUtils;
 import org.springframework.web.servlet.FlashMap;
 import org.springframework.web.servlet.FlashMapManager;
 import org.springframework.web.util.UrlPathHelper;
 
 /**
- * A default {@link FlashMapManager} implementation keeps {@link FlashMap}
+ * A default {@link FlashMapManager} implementation that stores {@link FlashMap}
  * instances in the HTTP session.
  * 
  * @author Rossen Stoyanchev
@@ -122,9 +123,10 @@ public class DefaultFlashMapManager implements FlashMapManager {
 				return false;
 			}
 		}
-		if (flashMap.getTargetRequestParams() != null) {
-			for (String paramName : flashMap.getTargetRequestParams().keySet()) {
-				if (!flashMap.getTargetRequestParams().get(paramName).equals(request.getParameter(paramName))) {
+		MultiValueMap<String, String> params = flashMap.getTargetRequestParams();
+		for (String key : params.keySet()) {
+			for (String value : params.get(key)) {
+				if (!value.equals(request.getParameter(key))) {
 					return false;
 				}
 			}

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

@@ -43,6 +43,8 @@ import org.springframework.web.servlet.HandlerMapping;
 import org.springframework.web.servlet.SmartView;
 import org.springframework.web.servlet.View;
 import org.springframework.web.servlet.support.RequestContextUtils;
+import org.springframework.web.util.UriComponents;
+import org.springframework.web.util.UriComponentsBuilder;
 import org.springframework.web.util.UriUtils;
 import org.springframework.web.util.WebUtils;
 
@@ -240,11 +242,9 @@ public class RedirectView extends AbstractUrlBasedView implements SmartView {
 
 		FlashMap flashMap = RequestContextUtils.getOutputFlashMap(request);
 		if (!CollectionUtils.isEmpty(flashMap)) {
-			String targetPath = WebUtils.extractUrlPath(targetUrl.toString());
-			flashMap.setTargetRequestPath(targetPath);
-			if (this.exposeModelAttributes) {
-				flashMap.addTargetRequestParams(model);
-			}				
+			UriComponents uriComponents = UriComponentsBuilder.fromUriString(targetUrl).build();
+			flashMap.setTargetRequestPath(uriComponents.getPath());
+			flashMap.addTargetRequestParams(uriComponents.getQueryParams());
 		}
 		
 		sendRedirect(request, response, targetUrl.toString(), this.http10Compatible);