Add protected method for required RequestBody

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2016 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.
@@ -146,7 +146,7 @@ public class RequestResponseBodyMethodProcessor extends AbstractMessageConverter
 
 		Object arg = readWithMessageConverters(inputMessage, methodParam, paramType);
 		if (arg == null) {
-			if (methodParam.getParameterAnnotation(RequestBody.class).required()) {
+			if (checkRequired(methodParam)) {
 				throw new HttpMessageNotReadableException("Required request body is missing: " +
 						methodParam.getMethod().toGenericString());
 			}
@@ -154,6 +154,10 @@ public class RequestResponseBodyMethodProcessor extends AbstractMessageConverter
 		return arg;
 	}
 
+	protected boolean checkRequired(MethodParameter methodParam) {
+		return methodParam.getParameterAnnotation(RequestBody.class).required();
+	}
+
 	@Override
 	public void handleReturnValue(Object returnValue, MethodParameter returnType,
 			ModelAndViewContainer mavContainer, NativeWebRequest webRequest)