Polishing

spring-web/src/main/java/org/springframework/web/bind/WebDataBinder.java

@@ -201,8 +201,8 @@ public class WebDataBinder extends DataBinder {
 	 * @see #getFieldDefaultPrefix
 	 */
 	protected void checkFieldDefaults(MutablePropertyValues mpvs) {
-		if (getFieldDefaultPrefix() != null) {
-			String fieldDefaultPrefix = getFieldDefaultPrefix();
+		String fieldDefaultPrefix = getFieldDefaultPrefix();
+		if (fieldDefaultPrefix != null) {
 			PropertyValue[] pvArray = mpvs.getPropertyValues();
 			for (PropertyValue pv : pvArray) {
 				if (pv.getName().startsWith(fieldDefaultPrefix)) {
@@ -228,8 +228,8 @@ public class WebDataBinder extends DataBinder {
 	 * @see #getEmptyValue(String, Class)
 	 */
 	protected void checkFieldMarkers(MutablePropertyValues mpvs) {
-		if (getFieldMarkerPrefix() != null) {
-			String fieldMarkerPrefix = getFieldMarkerPrefix();
+		String fieldMarkerPrefix = getFieldMarkerPrefix();
+		if (fieldMarkerPrefix != null) {
 			PropertyValue[] pvArray = mpvs.getPropertyValues();
 			for (PropertyValue pv : pvArray) {
 				if (pv.getName().startsWith(fieldMarkerPrefix)) {
@@ -246,7 +246,7 @@ public class WebDataBinder extends DataBinder {
 
 	/**
 	 * Determine an empty value for the specified field.
-	 * <p>Default implementation returns:
+	 * <p>The default implementation returns:
 	 * <ul>
 	 * <li>{@code Boolean.FALSE} for boolean fields
 	 * <li>an empty array for array types
@@ -275,17 +275,20 @@ public class WebDataBinder extends DataBinder {
 				else if (Map.class.isAssignableFrom(fieldType)) {
 					return CollectionFactory.createMap(fieldType, 0);
 				}
-			} catch (IllegalArgumentException exc) {
-				return null;
+			}
+			catch (IllegalArgumentException ex) {
+				if (logger.isDebugEnabled()) {
+					logger.debug("Failed to create default value - falling back to null: " + ex.getMessage());
+				}
 			}
 		}
-		// Default value: try null.
+		// Default value: null.
 		return null;
 	}
 
 	/**
 	 * Bind all multipart files contained in the given request, if any
-	 * (in case of a multipart request).
+	 * (in case of a multipart request). To be called by subclasses.
 	 * <p>Multipart files will only be added to the property values if they
 	 * are not empty or if we're configured to bind empty multipart files too.
 	 * @param multipartFiles Map of field name String to MultipartFile object

spring-web/src/main/java/org/springframework/web/context/request/async/CallableProcessingInterceptor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -36,7 +36,7 @@ import org.springframework.web.context.request.NativeWebRequest;
  * the Exception instance as the concurrent result. Such exceptions will then
  * be processed through the {@code HandlerExceptionResolver} mechanism.
  *
- * <p>The {@link #handleTimeout(NativeWebRequest, Callable) afterTimeout} method
+ * <p>The {@link #handleTimeout(NativeWebRequest, Callable) handleTimeout} method
  * can select a value to be used to resume processing.
  *
  * @author Rossen Stoyanchev
@@ -45,9 +45,20 @@ import org.springframework.web.context.request.NativeWebRequest;
  */
 public interface CallableProcessingInterceptor {
 
-	static final Object RESULT_NONE = new Object();
+	/**
+	 * Constant indicating that no result has been determined by this
+	 * interceptor, giving subsequent interceptors a chance.
+	 * @see #handleTimeout
+	 */
+	Object RESULT_NONE = new Object();
+
+	/**
+	 * Constant indicating that the response has been handled by this interceptor
+	 * without a result and that no further interceptors are to be invoked.
+	 * @see #handleTimeout
+	 */
+	Object RESPONSE_HANDLED = new Object();
 
-	static final Object RESPONSE_HANDLED = new Object();
 
 	/**
 	 * Invoked <em>before</em> the start of concurrent handling in the original

spring-web/src/main/java/org/springframework/web/method/annotation/ExceptionHandlerMethodResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -94,7 +94,9 @@ public class ExceptionHandlerMethodResolver {
 				}
 			}
 		}
-		Assert.notEmpty(result, "No exception types mapped to {" + method + "}");
+		if (result.isEmpty()) {
+			throw new IllegalStateException("No exception types mapped to " + method);
+		}
 		return result;
 	}