Allow greater flexibility for template method createDataBinderFactory

Prior to this commit, the template method createDataBinderFactory
would only allow ServletRequestDataBinderFactory as a return type.

This commit updates the method signature and allows
InitBinderDataBinderFactory, a superclass of the previous one.
Then other implementations can override this method and return
other InitBinderDataBinderFactory types.

Issue: SPR-10920

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

@@ -73,6 +73,7 @@ import org.springframework.web.method.HandlerMethod;
 import org.springframework.web.method.HandlerMethodSelector;
 import org.springframework.web.method.annotation.ErrorsMethodArgumentResolver;
 import org.springframework.web.method.annotation.ExpressionValueMethodArgumentResolver;
+import org.springframework.web.method.annotation.InitBinderDataBinderFactory;
 import org.springframework.web.method.annotation.MapMethodProcessor;
 import org.springframework.web.method.annotation.ModelAttributeMethodProcessor;
 import org.springframework.web.method.annotation.ModelFactory;
@@ -826,14 +827,14 @@ public class RequestMappingHandlerAdapter extends AbstractHandlerMethodAdapter i
 	}
 
 	/**
-	 * Template method to create a new ServletRequestDataBinderFactory instance.
+	 * Template method to create a new InitBinderDataBinderFactory instance.
 	 * <p>The default implementation creates a ServletRequestDataBinderFactory.
 	 * This can be overridden for custom ServletRequestDataBinder subclasses.
 	 * @param binderMethods {@code @InitBinder} methods
-	 * @return the ServletRequestDataBinderFactory instance to use
+	 * @return the InitBinderDataBinderFactory instance to use
 	 * @throws Exception in case of invalid state or arguments
 	 */
-	protected ServletRequestDataBinderFactory createDataBinderFactory(List<InvocableHandlerMethod> binderMethods)
+	protected InitBinderDataBinderFactory createDataBinderFactory(List<InvocableHandlerMethod> binderMethods)
 			throws Exception {
 
 		return new ServletRequestDataBinderFactory(binderMethods, getWebBindingInitializer());